Insight into ovarian follicular dynamics and hormonal interplay during estrus period in Lakhimi cow of Assam

Insight into ovarian follicular dynamics and hormonal interplay during estrus period in Lakhimi cow of Assam | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Insight into ovarian follicular dynamics and hormonal interplay during estrus period in Lakhimi cow of Assam Anupam Datta, Anubha Baruah, Arundhati Bora, Devojyoti Dutta, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-2926683/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Lakhimi is a very promising indigenous dual cattle breed of Assam, India, with their superior draught power capacity, heat tolerance, disease resistance, and adaptability to harsh agro-climatic conditions. The present study was designed to monitor the ovarian follicular dynamics and hormonal profile during the estrus cycle in Lakhimi cows. The study revealed that two follicular wave cycles were predominant (66.7%) in Lakhimi cows with the least duration of ovulatory wave in both two and three-wave cycles. The emergence of wave in the two-wave cycle was 1.16 ± 0.30 and 10.83 ± 0.47 while in three wave cycle on day 0.83 ± 0.16, 7.33 ± 0.49, and 12.16 ± 0.47 of the cycle. The number of the antral follicular count was more in two waves estrous cycle (4.33 ± 0.49 number in the ovulatory wave) compare to three wave cycle with 3.66 ± 0.33 number of follicles. The maximum size of the DF two and three follicular waves were 11.51 ± 0.54 mm and 12.41 ± 0.69 mm respectively. The hormonal dynamics were characterized by peak progesterone concentration (ng/ml) on day 10th day. estradiol on the 20th (the day before estrous) and the day of heat, and LH peak on the 1st day of estrous with subsequent low concentration in Lakhimi Cows. So ovarian follicular waves in Lakhimi cows were characterized by two wave cycles with a low antral follicular count, less diameter of DF, and lower concentration of LH, Progesterone, and estradiol. Assam Local Cow. Follicular wave. Lakhimi cow. Ovary. Oestrus Cycle Figures Figure 1 Figure 2 Figure 3 Introduction India has 41 recognized indigenous breeds of cattle (ICAR-NBAGR, India) and the state of Assam possesses 8.4 million cattle out of which 7.9 million are indigenous (Source: Directorate of Animal Husbandry and Veterinary Department, Assam India). The indigenous cattle of Assam Lakhimi a small-sized, dual-purpose registered breed of India ((ICAR-NBAGR, India) have evolved through several generations of natural selection. The importance of these animals lies in their draught power capacity, heat tolerance, disease resistance, adaptability to harsh agro-climatic conditions, and ability to survive and perform under scarce feed and fodder. The optimum reproductive rhythm of the animal within the normal physiological range is key to production and performance in cows. Understanding, the ovarian follicular interplay during the oestrus cycle is essential to interpret the reproductive behavior of this breed. Ovarian follicular dynamics in cows are characterized by follicular waves growth and regression during the estrous cycle (Savio et al. 1993; Knopf et al.1989) under the influence of serum FSH for recruitment of follicles (2 - 5 mm) to become dominant (Ginther et al.1996), the selection of dominant follicles, and regression of subordinate follicles (Fortune et al. 1993;2003). Bovine usually shows two (Knopf et al. 1989; Taylor et al. 1991) or three (Savio et al.1988; Sirois et al. 1988) follicular waves during the estrous cycle, but cycles with one (Savio et al.1988) or four (Sirois et al. 1988) follicular waves are also found. Bovine follicular wave is varied with the breed (Figueiredo et al.1997), reproductive stage (Roche et al.1991), season (Lucy et al.1992; energy balance (Rhodes et al.1995), and body score condition. The association of ovarian follicular number in bovine with high repeatability (Ireland et al. 2008; Morotti et al. 2015;2017; Zangirolamo et al. 2018; Seneda et al. 2019) and reproductive performance is reported by (Burns et al. 2005; Evans et al. 2012, Ireland et al. 2011; Jimenes et al. 2017; Santos et al. 2016; Silva-Santos et al. 2014; Morotti et al. 2018; Moraes et al. 2019; Moraes et al. 2019; Morotti et al. 2018; De Lima et al. 2020). However, the exact dynamics of follicular wave remain unknown at the breed level, individual level, and its influence on cattle fertility. Low numbers of antral follicles in female cattle have been associated with poor reproductive performance (Mossa et al. 2012), small ovaries and reduced endometrial thickness (Jaminez et al. 2009), poor embryo (Ireland et al. 2008; Singh et al. 2004). The study of bovine follicular dynamics is not a new venture ( Savio et al.1993; Sunderland et al.1994; Bergfeld et al. 1994). It revealed many variations in timing, cycle patterns, and individuality (Ireland et al. 2008; Morotti et al. 2015;2017; Zangirolamo et al. 2018; Seneda et al. 2019; Burns et al. 2005; Evans et al. 2012; Ireland et al. 2011; Jimenez et al. 2016; Santos et al. 2016; Silva-Santos et al. 2014; Morotti et al. 2018; Moraes et al; 2019). Assam local cattle (Lakhimi) are such important in this agro-climatic region no such literature is available regarding the follicular dynamic study. To explore the reproductive potentials of the locally evolved Lakhimi cow of Assam it is very essential to investigate the reproductive rhythm and follicular dynamics along with the interplay of progesterone, estradiol, pituitary-dependant follicle-stimulating hormone (FSH), luteinizing hormone. The study of follicular dynamics during the estrous cycle may help to clarify the phenomena that interfere in estrous synchronization and ovulation as well as in the ovarian response of superovulated animals and may improve fertility levels. (Bhosrekar et al. 2006). Materials And Methods Ethical Permission: The experiment was approved by the Institutional Ethical Committee Approval 770/ac/CPCSEA/FVSc/AAU/IAEC/17-18/569 Location of the experiment The study was conducted at the Experimental animal shed, Department of Veterinary Physiology, College of Veterinary Science, AAU, Khanapara. RIA (Radio immune assay) was performed at NRL (Nuclear research laboratory), Department of Veterinary Physiology, College of Veterinary Science, AAU, Khanapara. ELISA was conducted at the Department of Veterinary Microbiology, College of Veterinary Science, AAU, Khanapara, Assam. Experimental animals and their management Six Assam local (Lakhimi) adult healthy cyclic cows, dewormed, routinely vaccinated (fig-1) with good body score condition, without any reproductive abnormalities were selected for the study. All the Lakhimi cows had regular estrous cycles and were confirmed non-pregnant by rectal palpation and ultrasonography before the study. All the experimental cows were housed together in well-ventilated hygienic sheds and maintained under the same conditions throughout the study with ad libitum clean drinking water and fodder. Preparation of animals for ultrasonography The animal selected for ultrasonography was restrained in a standing position for scanning in the Travis, The area was prepared for darkness to observe the fine details of images for necessary interpretation. Ultrasound scanning of the ovary: All cows were scanned by using a real-time, B-mode, ultrasound scanner (M turbo C, Fujifilm Sonosite Inc., Bothell, USA) equipped with a 7.5-9.0 MHz linear rectal transducer adapted for transrectal examination in large domestic animals. The ultrasound scanning was undertaken on lateromedial and dorsoventral planes to monitor ovarian follicular dynamics. Follicular measurements were recorded (length and width), throughout an estrous cycle starting from observed estrus (day 0) to subsequent standing estrus. The day-to-day identity of follicles was profiled as described by Tom et al. (1998). The number of follicles recruited (as evidenced by small 3-4 mm size follicles on the day of emergence) and the characteristics of the dominant follicles (DFs) during the first follicular wave (Wave I) and ovulatory wave were compared. Various observations like follicular, luteal dimensions, development, and regression days, in different waves were recorded. Each ovary was scanned for the positions of the antral follicles and corpus luteum. Small follicles, medium, large, and ovulatory follicles (fig-3) were identified with diameters of - 3mm to 6mm, above 6mm to 9mm, above 9 mm, and more than 9 mm respectively. Blood samples and hormone assay: 5 ml blood samples were collected on every alternate day of an estrous cycle in heparinized tubes and placed on ice immediately after collection. Plasma was separated by centrifuging the blood sample at 1500 rpm for 15 minutes, within 30 minutes of blood collection, and transferred to cryovials and stored at -20˚c until assayed for hormones. Estimation of hormone: The concentration of P4 was measured with a solid phase RIA kit (Progesterone C.T. RIA kit (Pkg: 100 T) Batch No 181008D, M/s Beckman Coulter; supplied by M/S Anand brothers New Delhi) and the radioactivity was counted in a 125I (STRATEC Germany) gamma counter. Serum Estradiol and LH assay employs the competitive enzyme immunoassay technique. The microtiter plate provided in this kit has been pre-coated with E2 and LH antibodies. Statistical analysis was performed by Independent Sample T- test using SPSS Results The estrous cycle of the Lakhimi cow evaluated in this study presented the characteristic pattern of follicular growth and waves, initial development of a group of ≥ 3 mm follicles in each wave, followed by selection, development, and atresia of a dominant anovulatory follicle or ovulation of ovulatory dominant follicle. Two patterns (two and three) of follicular development were detected during twelve estrous cycles of the Lakhimi cows that were monitored. Lakhimi cows have a predominance of the estrous cycle with two follicular waves (66%). In the two-wave cycle (fig-2a), the first and second wave emerged on day 1.16 ± 0.30 and 10.83 ± 0.47 of the cycle and was followed by selection (divergence) of DF on day 5.5 ± 0.42 and 14.83 ± 0.60 of the cycle while in three wave cycle (fig-2b, table-1), first, second and third wave emerged on day 0.83 ± 0.16, 7.33 ± 0.49 and 12.16 ± 0.47 of the cycle and was followed by selection (divergence) of DF on day 4.83 ± 0.30, 9.16 ± 0.31 and 15.5 ±0.5. The divergence of follicles is defined as the difference in growth rates between the two larger follicles and is marked by the continued development of the largest follicle but a decline or stop in the growth of others (Table-1,2). In two wave estrous cycle, 3.5 ± 0.42 and 4.33 ± 0.49 number of follicles (>3 mm) emerged at the first and second wave emergence while in three wave cycles 3.83 ± 0.47, 2.83 ± 0.30 and 3.66 ± 0.33 number of follicles (>3 mm) emerged at first, second and third wave emergence in Lakhimi cows (Table-1,3). The maximum size of the DF of the first and second follicular wave in two wave estrous cycles was 8.49 ± 0.49 and 11.51 ± 0.54 mm on a mean day was 6.83 ± 0.40 and 20.16 ± 0.30 while the maximum size of the DF of the first, second and third follicular wave in three wave cycle was 9.41 ± 0.87, 8.51 ± 0.26 and 12.41 ± 0.69 mm on the mean day 6.16 ± 0.47, 15.5 ± 0.56 and 20.33 ± 0.33 in Lakhimi cows (Table-2,4). First-wave DF reached its maximum size during the luteal phase, it persisted for 3-6 days and then underwent atresia while second-wave DF reached its maximum size during luteal regression and ovulated. The first wave dominant follicle of the two waves estrous cycle underwent atresia on the mean (±SE) day 8.83 ± 0.30 whereas in three wave cycle first and second wave dominant follicles underwent atresia on the mean (± SE) day 7.83 ± 0.30 and 15.16 ± 0.40 in Lakhimi cows. In two-wave cycles, ovulation occurred on the mean (± SE) day 20.16 ± 0.30 whereas in three wave cycle, ovulation occurred on the mean (± SE) day 20.33 ± 0.33. Time of ovulation may be variable because these studies were done on a day basis, so there may be chances of biases in the detection time of the start of overt signs of estrus. In two wave estrous cycle, the first and second waves persisted for 14.33 ± 0.55 and 10.66 ± 0.49 days whereas, in three wave cycle first, second and third waves persisted for 14.16 ± 0.40, 11.83 ± 0.60, and 7.16 ± 0.47 days (Table-3,4). Hormonal profiles during the estrous cycle of Lakhimi cows The concentration of progesterone (ng/ml) was found highest in cows up to day 10 of the estrous cycle (10.94 ±1.93) and declined towards the end of the cycle up to the next estrus. In the present study, serum progesterone levels ranged from 0.41 to 1.54 ng/ml during the follicular phase and between 3.52 to 10.94 ng/ml during the luteal phase. The level of estradiol was highest on the day before estrus (day 20) and on the day of heat (day 0) during the estrous cycle (192±11.35) and day 20 (118±13.81). However, the level of estradiol was maintained very low on other days of the estrous cycle. The serum LH (ng/ml) level of the Lakhimi cow was found highest on day 1 of the estrous cycle (7.97±1.03). The LH level however was maintained at a very low concentration on other days of the estrous cycle in both the group of animals (table-5). Table No-1 D ifferent ovarian follicular of characteristics (mean±se) of two wave cycle in L akhimi cows Characteristics Follicular Waves 1 st (Anovulatory) 2 nd (Ovulatory) Day of Wave emergence 1.16±0.30 10.83±0.47 No. of Follicles (>3mm) 3.5±0.42 4.33±0.49 Day of emergence of DF 5.5±0.42 14.83±0.60 Maximum diameter of DF 8.49±0.49 11.51±0.54 Day of maximum diameter 6.83±0.40 20.16±0.30 Day of onset of atresia 8.83±0.30 - Day of termination of wave 13.66±0.42 - Duration of persistence of wave (days) 14.33 10.66±0.49 Table No-2 T he mean±se of the follicle diameter (mm) at different days in two wave cycle in L akhimi cows Days of estrous cycle 1 st Follicular wave 2 nd Follicular wave Day 0 4.2000±0.44721 - Day 2 5.3000±0.49193 - Day 4 6.0117±0.48666 - Day 6 8.4967±0.49165 - Day 8 5.6950±0.53762 - Day 10 6.3983 ± 0.59200 4.4983 ± 0.63518 Day 12 4.3117 ± 0.60159 6.1950 ± 0.40261 Day 14 - 8.8100 ± 0.52472 Day 16 - 8.9950 ± 0.53611 Day 18 - 9.4950 ± 0.58092 Day 20 - 11.2200 ± 0.68172 Day 21 - 11.5117 ± 0.54980 Table: 3. O varian follicular characteristics (mean±se) of three wave cycle in L akhimi cows Characteristics Follicular Waves 1 st (Anovulatory) 2 nd Anovulatory) 3 rd (Ovulatory) Day of Wave emergence 0.83 ± 0.16 7.33 ± 0.49 12.16 ± 0.47 No. Of Follicles (>3mm) 3.83 ± 0.47 2.83 ± 0.30 3.66 ± 0.33 Day of emergence of DF 4.83 ± 0.30 9.16 ± 0.31 15.5 ±0.5 Maximum diameter of DF 9.41 ± 0.87 8.51 ± 0.26 12.41 ± 0.69 Day of maximum diameter 6.16 ± 0.47 15.5 ± 0.56 20.33 ± 0.33 Day of onset of atresia 7.83 ± 0.30 15.16 ± 0.40 Day of termination of wave 14.33 ± 0.42 19.16 ± 0.47 Duration of persistence of wave (days) 14.16 ± 0.40 11.83 ± 0.60 7.16 ± 0.47 Table : 4 Mean±SEof the follicle diameter (mm) at different days in three wave cycle Days of estrous cycle 1 st Follicular wave 2 nd Follicular wave 3 rd Follicular wave Day 0 - - - Day 2 4.3117 ± 0.43593 Day 4 5.8450 ± 0.91365 Day 6 9.4117 ± 0.87254 3.5067 ± 0.47532 - Day 8 9.2283 ± 0.54345 4.6283 ± 0.49127 - Day 10 6.2317 ± 0.54287 5.7117 ± 0.56724 - Day 12 4.1450 ± 0.55115 7.3283 ± 0.60960 4.0483 ± 0.46914 Day 14 3.0083 ± 0.70524 7.7300 ± 0.38221 6.5283 ± 0.77125 Day 16 - 8.5167 ± 0.26594 7.8133 ± 0.78803 Day 18 - 7.5267 ± 0.82291 9.3967 ± 0.58485 Day 20 - 4.8133 ± 0.44034 11.8017 ± 0.59335 Day 21 - - 12.4150 ± 0.69786 TABLE 5 : S erum progesterone , estradiol and LH (ng/ml) profile (mean±se) in L akhimi cows Days of estrous cycle Maen concentration of Serum progesterone (ng/ml) Maen concentration of Serum estradiol (ng/ml) Maen concentration of Serum LH (ng/ml) Day 0 0.41±0.09 192±11.35 2.61±0.53 Day 1 0.43±0.08 29±3.03 7.97±1.03 Day 2 0.56±0.08 28±2.79 1.85±0.41 Day 4 4.63±0.54 25±0.44 1.82±0.41 Day 6 7.69±1.43 20±1.6 0.91±0.20 Day 8 8.92±1.43 25±1.4 0.91±0.20 Day 10 10.94±1.93 21±1.2 0.79±0.09 Day 12 10.34±0.93 15±1.58 0.67±0.09 Day 14 7.77±1.07 12±1.24 0.54±0.09 Day 16 3.52±0.67 12±1.44 0.78±0.12 Day 18 1.54±0.40 79±9.18 1.01±0.12 Day 20 0.71±0.14 118±13.81 1.52±0.14 Discussion Follicular wave cycles in general (2-3) with the predominance of two follicular waves (66%) were recorded in Lakhimi cows. Similar observations were also recorded by many authors (Nelore cow- Figueiredo et al.1997; Crossbred cows- Filho et al. 2001; Crossbred cows- Alves et al. 2002; European cows – Burns et al. 2005 and Rathi cows – Gaur et al. 2007; Islam et al. 2020 in Red Chittagong cows). However, cycles with three follicular waves were also observed in indigenous Zebu cattle by Gambini et al. (1998). No cycle was observed with four or more follicular waves during the present study. Viana et al. (2000) recorded a small proportion of cows showing four and five follicular waves during the estrous cycle in Gir cows. Factors like the length of the luteal phase (Figueiredo et al. 1997), follicular size, estradiol concentration (Nosier et al. 2003), peaks of FSH (Adams et al. 2008) and IGF (Alveraz et al. 2000) may have an important role in determining waves of the follicle during the estrous cycle. Before the rise of a follicular wave peaks of FSH occur, and the number of peaks is related to the number of follicular developments in cows (Adams et al. 2008). In the present study, in the two-wave cycle, the emergence of the first and second wave can be compared with those of Bahaman heifers on Day 0.2 ± 0.1 and Day 10.0 ± 0.4 (Rhodes et al. 1995) and Day 1.50 ± 0.15 and 12.0 ± 0.91 in Nelore cattle (Figueiredo et al.1997). However, Islam et al. (2020) reported 2.00 ± 1.50 and 12.00 ± 2.10 days respectively in two wave cycles in Red Chittagong cows. Follicular wave lengths during 1st and 2nd waves in Lakhimi cows were delayed compared to Red Chittagong cows (Islam et al. 2020) on 12.44 ± 0.08 and 8.07 ± 0.06 days but concomitant to Nelore cattle on day 14.75 ± 0.70 and 9.05 ± 0.69 (Figueiredo et al. 1997) respectively. The three wave cycles in Lakhimi cows were similar to Zebu cows (Viana et al. 2000) and crossbred cows (Jaiswal et al. 2007; Filho et al. 2001). The variations in the persistence of waves in different breeds may be influenced by the pulsatile frequency of LH (Lucy et al. 1992), and progesterone (Gambini et al.1998). In the present study the day of emergence, followed by selection (divergence) of DF in Lakhimi cows were correspondent to observations by Figueiredo et al. (1997) in Nellore cows; Gir (Gambini et al. 1998); crossbred (Filho et al. 2001; Jaiswal et al. 2007). The presence of more numbers of ovarian follicles (>3mm) in two waves estrous cycle than in the three waves in the Lakhimi cow were in correspond to the Sirois et al. (1988z) in Holstein heifer, Alvarez et al. (2000) in Brahman cows, Amrozi et al. (2004) in Holstein cows and Jaiswal et al. (2007) in Crossbred cows. However, Islam et al. (2020) reported 8.00 ± 1.50 and 6.50 ± 1.70 numbers of follicles in Red Chittagong Cows. Variations in the number of follicles reported may be due to individual differences (Boni et al.1997), serum growth hormone, and IGF-I (Lucy et al.1992; Gong et al.1996) concentration. Season (Lammoglia et al.1998) and nutrition status (Lucy et al.1992) of cow. The ovarian antral follicular count is an important indicator of fertility and the number of follicles varies with breed, ovarian dimension, heritability, and size of the dominant follicle (Lima et al. 2020). The maximum size of the DF of the first and second follicular waves was smaller (8.49 ± 0.49 and 11.51 ± 0.54 mm) than in Red Chittagong cows (10-11 mm) (Islam et al. 2020), Nelore heifers (10 - 12 mm) (Figueiredo et al. 1997), Holstein heifers (14 - 20 mm), Brahman heifers (13 - 18 mm) (Rhodes et al. 1995) and similar to the DF (8 - 9 mm) reported for Chinese Yellow Cattle (Vasconcelos et al. 2001). However, the maximum diameter of DF during three follicular waves in Lakhimi cows was in agreement with the observations made by Gambini et al. (1998) in Gir and Nellore cows, Gaur et al. 2007 in Rathi cows) and Filho et al. (2001) in crossbred cows. Though the pattern of growth and turnover of DF were similar to Nellore, and Brahman cows but the sizes of DF in the ovaries of Lakhimi cows can be compared with Red Chittagong Cow but smaller than those of Nelore and Brahman heifers and Holstein. In the present study, DF reached maximum size during the luteal phase, it persisted for 3-6 days and then underwent atresia while second wave DF reached its maximum size during luteal regression and ovulated. This finding matches the reports on Rathi cows by Gaur et al. (2007), Zebu cows by Viana et al. (2000), and crossbred cows by Filho et al. (2001). The difference in attaining a maximum diameter of DF may be because the second wave emerges during the period of higher progesterone production by the CL, whereas the first and third waves emerge respectively during the luteogenic and luteolytic periods (Viana et al. 2000; Gambini et al. 1998). during first follicular wave due to low concentration of progesterone, satisfactory negative feedback can not be generated on hypothalamic-pituitary to prevent the release of luteinizing hormone. The second wave started in the presence of fully formed CL that secretes a high concentration of progesterone, sufficient to inhibit the release of LH. Low-frequency pulses of LH were observed during the luteogenic and luteal phases of the estrous cycle, leading to regression of the DF and initiation of a new follicular wave (Gambini et al.1998). The third wave coincides with the reduced secretion of progesterone by the CL, resulting in an increased frequency of pulses of LH to a peak. This phase is to check the rapid follicular growth and ovulation (Savio et al.1993). The lower concentration of progesterone present during luteogenic and luteolytic periods may be associated with higher gonadotrophic concentration and consequently with higher diameter and persistency of DFs. Maximum size of the wave DF is proportional to the FSH release inhibition (Ginther et al.1996) but the final maturation and ovulation of DF are dependent on a high frequency of LH pulses (Roche et al. 1991). Nutritional status also influences the follicular dynamics during the estrous cycle. Maximum diameter and persistence of DF reduced in case of negative energy balance (Rhodes et al.1995). The mean day of follicular atresia in Lakhimi cows was in agreement with the findings by Ginther et al. (1996) in Holstein cows, Jaiswal et al. (2007) in crossbred cows, and Gaur et al.(2007) in Rathi cows. The day of ovulation accounted in the present study for two and three waves is in agreement with Gambini et al. (1998) in Gir and Nelore cows, Pinheiro et al. (1998) in European cows. Time of ovulation may be variable because these studies were done daily, so there may be chances of biases in the detection time of the start of overt signs of estrus. The duration of growth of ovulatory follicle (OF) in Lakhimi cows can be comparable with two follicular wave cycles of Red Chittagong cows (8.24 ± 0.56 and 9.51 ± 0.68 days) Islam et al. (2020), Nelore cattle with two and three follicular wave cycles (8.65 ± 0.73 and 7.0 ± 0.51 days) Figueiredo et al. (1997) and Holstein heifers with two and three follicular waves cycles (7.50 ± 0.19 and 5.90 ± 0.30 days). Slower rates of follicular growth were recorded compared to those of Nelore cattle and Holstein heifers, which may be a breed variation. The follicular deviation after ovulation in Lakhimi cows in the present study during the two and three-wave cycle was approximately 2 days and Islam et al. (2020) reported 1.53 days in Red Chittagong cows. The emergence of the first follicular wave does not usually occur until 24 h after ovulation in Lakhimi Cow therefore, follicular deviation seems to occur earlier than in Nelore and Holstein females. (Fortune et al. 2003) Hormonal profile in Lakhimi Cows concerning follicular dynamics. The peak progesterone (ng/ml) concentration on the 10th day of the estrous cycle was followed by a decline towards the end of the cycle up to the next heat/estrus with a range from 0.41 to 1.54 ng/ml during the follicular phase and 3.52 to 10.94 ng/ml during luteal phase of the estrous cycle in Lakhimi cows. A similar trend of progesterone levels during the estrous cycle has been reported by Saini et al. (2021); Islam et al. (2020) in indigenous cows; Oyedipe et al. (1986) in Nigerian zebu cows. However, the magnitude of serum progesterone may vary from breed to breed. Islam et al. (2020) observed a progressive increase in serum progesterone from <1 ng/ml to ≥27 ng/ml on days 4 - 6 and consequent follicular deviation in Red Chittagong cows. Progesterone plays an important role in follicle development, and the functional status of CL and also affect LH secretion (Noseir et al. 2003; McDonald et al.1980). The post-ovulatory rise in progesterone level occurs due to luteinization of follicular cells and the development of the corpus luteum. Developing corpus luteum is the source of high progesterone concentration during luteal phase of the cycle under the stimulation of LH hormone (Islam et al.2020). High progesterone levels during luteal phase are required for the creation of a uterine environment for the successful implantation of the zygote. Mid-cycle high progesterone level exerts its negative feedback action on the hypothalamic hypophyseal axis, thus preventing follicular maturation and ovulation. A decline in serum progesterone levels beyond day 13, recorded in this study, collated with the regression of corpus luteum. The level of estradiol in the Lakhimi cow during the estrous cycle was highest on the day before estrus, on day 0, and maintained a low concentration throughout the cycle, as reported by Islam et al. 2020). Only a peak concentration of LH in the Lakhimi cow on day 1 of the estrous cycle, was maintained at a very low throughout the cycle which is crucial for final oocyte maturation as reported by Dias et al. (2010). The ovarian follicular dynamics pattern in Lakhimi cows followed two wave patterns mostly with low numbers of follicles (>3mm). The circulating serum progesterone, estradiol, and LH concentrations dynamics are almost similar to other indigenous cows. However, the size of the dominant follicle and pre-ovulatory follicles were smaller than the cross-breed Holstein and can be comparable with the local indigenous breeds like zebu, red Chittagong cows, Bhraman cow, etc. De Lima et al. (2020) have pointed the close relationship between follicular dynamics, progesterone concentrations, pregnancy rates with a high or low antral follicle count in Bos Indicus. Documentation of an ovarian follicular wave phenomenon in this potential Lakhimi cattle breed will provide insight for understanding the folliculogenesis of native cattle estrus cycle, proper heat detection, the timing of artificial insemination, and have profound implications for infertility diagnosis, repeat breeding, and treatment. To explore the optimum reproductive potential and to preserve the germplasm, future works may be initiated to identify the follicular number, and DF size concerning fertility index with its molecular mechanism for this breed. Declarations Funding Directorate of Biotechnology Govt of India under twinning project Programme Conflicts of Interest We declare no conflict of interest. Acknowledgement : Authors are extending thanks to the Directorate of Biotechnology Govt of India for the Financial support, Dean FVSc AAU Assam India for providing all the facilities, Head Department of Veterinary Physiology and Department of Animal Reproduction Gynaecology and obstetrics for providing all the kind help for carrying out the research work Data availability The authors declare that all the data and materials used in this study comply with field standards and are available on demand. Authors contribution : All authors contributed to the study’s conception and design. Material preparation, data collection, and analysis were performed by Anupam Datta , Anubha Baruah, Arundhati Bora, D.J. Dutta,J. Goswami,D. Bhuyan, The first draft of the manuscript was written by Sukanta Das, Avishek Paul and Anupam Datta .All authors read and approved the final manuscript. References Https: //nbagr.icar.gov.in/en/home/ Alvarez, P., Spicer, L. J., Chase Jr, C. C., Payton, M. E., Hamilton, T. D., Stewart, R. E., Hammond, A. C., Olson,T. A., Wettemann, R. P. (2000).Ovarian and endocrine characteristics during an estrous cycle in Angus, Brahman, and Senepol cows in a subtropical environment. Journal of Animal Science, 78(5), 1291–1302 Adams, G.P., Jaiswal, R., Singh, J. and Malhi, P. (2008) Progress in Understanding Ovarian Follicular Dynamics in Cattle. Theriogenology, 69, 72–80 Alves, N. G., Da Costa, E. P., Guimaraes, J. D., Silva, M. R., Zamperlini, B., Costa, F. M. J., Santos, A. D. F., Miranda-Neto, T. (2002). Ovarian activity in Holstein and crossbred Holstein X Zebu cows during two normal estrous cycles. Revista Brasileira-de-zootecnia, 31(2), 627–634 Amrozi, A., Kamimura, S., Ando, T., Hamana, K. (2004). Distribution of estrogen receptor alpha in the dominant follicles and corpus luteum at the three stages of estrous cycle in Japanese black cows. The Journal of Veterinary Medical Science, 66,1183–1188 Bergfeld, E. G. M., Kojima, F. N., Cupp, A. S., Wehrman, M. E., Peters, K. E., GarciaWinder, M., Kinder, J. E. (1994). Ovarian follicular development in prepubertal heifers os influenced by level of dietary energy intake. Biology of Reproduction, 51,1051–1057 Bhosrekar, M. R. (2006). Buffalo for rural upliftment fertility management of buffaloes, National symposium on Buffalo for Rural upliftment- Physiology and Reproduction. May, 27–30, Bombay Veterinary College, Mumbai, pp. 67 Boni, R., Roelofsen, M.W.M., Pieterse, M. C., Kogut, J.,Kruip, T. (1997). Follicular dynamics, repeatability and predictability of follicular recruitment in cows undergoing repeated follicular puncture. Theriogenology, 48(2), 277–289 Burns, D. S., Jimenez-Krassel, F., Ireland, J. L., Knight, P.G., Ireland, J. J. (2005). Numbers of antral follicles during follicular waves in cattle: evidence for high variation among animals, very high repeatability in individuals, and an inverse association with serum follicle-stimulating hormone concentrations. Biology of Reproduction, 73(1), 54–62 Dias, F. C., Colazo, M.G., Kastelic, J. P., Mapletoft, R.J., Adams, G.P., Singh, J. (2010) Progesterone concentration, estradiol pretreatment, and dose of gonadotropin-releasing hormone affect gonadotropin-releasing hormonemediated luteinizing hormone release in beef heifers. Domestic Animal Endocrinology, 39,155–162 De Lima, M.A., Morotti, F., Bayeux, B.M., Rezende, R.G., Botigelli, R.C., De Bem, Patrícia,T.H.C., Fontes, K., Nogueira, M.F.G., Meirelles, F.V., Baruselli, P.S., Silveira, J.C., Perecin,F., Seneda, M.M. (2020). Ovarian follicular dynamics, progesterone concentrations, pregnancy rates and transcriptional patterns in Bos indicus females with a high or low antral follicle count. Scientifc Reports, 10,19557 Evans, A.C.O., Currie, W. D., Rawlings, N.C. (2012). Effects of naloxone on circulating gonadotropin concentrations in prepubertal heifers from 2 to 36 weeks of age. Journal of Reproduction and Fertility, 102,463–470 Figueiredo, R. A., Barros, C. M., Pinheiro, O. P., Soler, J.M.P. (1997). Ovarian follicular dynamics in Nellore breed (Bos indicus) cattle. Theriogenology, 47(8), 1489–1505 Filho, S. A. S., Olivera, M. A. L., Caldaa, J. G. L., Lima, P. F., Donato, I. V. (2001). Ovarian follicular dynamics of five eight Girolando cows. Reproduction in Domestic Animals, 36(3–4), 207–210 Fortune, J. E. (1993). Follicular dynamics during the bovine oestrous cycle: a limiting factor in improvement of fertility. Animal Reproduction Science, 33(1–4),111–125 Fortune, J. E. (2003). The early stages of follicular development: activation of primordial follicles and growth of preantral follicles. Animal Reproduction Science, 78(3–4), 135–163 Gambini, A.L.G., Moreira, M.B.P. Castilho, C., Barros, C.M (1998). Follicular development and synchronization of ovulation in Gir cows. Brazilian Journal of Animal Reproduction, 22 (4), 201–210 Gaur, M., Purohit, G. N. (2007). Follicular dynamics in Rathi (Bosindicus) cattle. Veterinarski Arhiv, 77(2), 177–186 Ginther, O.J., Kot, K., Kulick, L.J., Martin, S.,Wiltbank, M.C. (1996). Relationships between FSH and ovarian follicular waves during the last six months of pregnancy in cattle. Journal of Reproduction and Fertility, 108, 271–279 Knopf, L., Kastelic, J.P., Schallenberger, E., Ginther, O. J. (1989). Ovarian follicular dynamics in heifers: Test of two wave hypothesis by ultrasonically monitoring individual follicles. Domestic Animal Endocrinology, 6(2),111–119 Lammoglia, M. A., Short, R. E., Bellows, S. E., Bellows, R. A., MacNeil, M. D., Hafs, H. D. (1998). Induced and synchronized estrus in cattle: Dose titration of estradiol benzoate in peripubertal heifers and postpartum cows after treatment with an intravaginal progesterone-releasing insert and prostaglandin F2α. Journal of Animal Science, 76, 1662–1670 Lucy, M. C., Savio, J. D., Badinga, R. L., De La Sota, R. L., Thatcher, W. W. (1992). Factors that affect ovarian follicular dynamics in cattle. Journal of Animal Science, 70, 3615–3626 McDonald, L. E. (1980). Veterinary Endocrinology and Reproduction, 3rd Edn. Lea and Febiger, Philadelphia. Oyedipe, E. O., Voh Jr, A. A., Marire, B. N., Pathiraja, N. (1986). Plasma progesterone concentrations during the oestrous cycle and following fertile and non-fertile insemination of zebu heifers. British Veterinary Journal, 142(1), 41–46 Pinheiro, O. L., Barros, C. M., Figueiredo, R. A., Do Valle, E. R., Encarnação, R. O., Padovani, C. R. (1998). Estrous behavior and the estrus-to-ovulation interval in nelore cattle (Bos indicus with natural estrus or estrus induced with prostaglandin F2α or norgestomet and estradiol valerate. Theriogenology, 49(3), 667–681 Rao, L. V., Pandey, R. S. (1982). Seasonal changes in plasma progesterone concentrations in buffalo cows (Bubalus bubalis). Reproduction, 66(1), 57–61 Rhodes, F. M., Fitzpatrick, L. A., Entwistle, K. W., De’ath, G. (1995). Sequential changes in ovarian follicular dynamics in Bos indicus heifers before and after nutritional anestrus. Journal of Reproduction Fertility, 104(1), 41–49 Roche, J. F., Boland, M. P. (1991).Turnover of dominant follicles in cattle of different reproductive states. Theriogenology, 35(1), 81–90 Savio, J. D., Thatcher, W. W., Bandinga, R. I., Sota, R. I., Wolfenson, D. (1993). Regulation of dominant follicle turnover during the oestrous cycle in cows. Journal of Reproduction Fertility, 7, 197–203 Sirois, J., Fortune, J.E. (1988) Ovarian follicular dynamics during the oestrous cycle in heifers monitored by real time ultrasonography. Biology of Reproduction, Madison, 39, 308–317 Sunderland, S. J., Crowe, M. A., Boland, M. P., Roche, J. F., Ireland, J. J. (1994) Selection, dominance and atresia of follicles during the oestrous cycle of heifers. Journal of Reproduction Fertility, 101, 547–555 Saini,G.,Yadav,V.,Kumar,S.,Pandey,A. (2021). Importance of indigenous cattle and peculiarity of their reproductive cycle: A review. The Pharma Innovation Journal,10(11), 156–159 Tom, J. W., Pierson, R. A., Adams, G. P. (1998). Quantitative echotexture analysis of bovine ovarian follicles. Theriogenology, 50, 339–346 Viana, J. H. M., A. de- M. Fereirs; W. F. de S. B., L. S. de A. Camargo (2000). Follicular dynamics in zebu cattle. Pesquira-Agropecuaria-Brasileira, 35(12), 2501–2509 Morotti, F. (2015). Is the number of antral follicles an interesting selection criterium for fertility in cattle. Animal Reproduction,12, 479–486. Morotti, F. (2017). Antral follicle count in cattle: Advantages, challenges, and controversy. Animal Reproduction, 14, 514–520 Zangirolamo, A. F., Morotti, F., da Silva, N. C., Sanches, T. K., Seneda, M. M.(2018). Ovarian antral follicle populations and embryo production in cattle. Animal Reproduction,15, 310–315 Seneda, M. M. (2019). Antral follicle population in prepubertal and pubertal heifers. Reproduction Fertility Development, 31, 10–16 Ireland, J. L. (2008). Antral follicle count reliably predicts number of morphologically healthy oocytes and follicles in ovaries of young adult cattle. Biology of Reproduction, 79, 1219–1225 Ireland, J. J. (2011). Does size matter in females? An overview of the impact of the high variation in the ovarian reserve on ovarian function and fertility, utility of anti-Mullerian hormone as a diagnostic marker for fertility and causes of variation in the ovarian reserve in cattle. Reproduction Fertility Development, 23, 1–14 Islam, S., Kabir, Md.A., Miraz, Md.F.H., Tamanna, E.J., Sarker, S.R., Islam, Z., Hossain, S.M.J., Hossain, S. and Deb, G.K. (2020) Investigation of Ovarian Follicular Waves and Major Hormonal Profile in Red Chittagong Cattle. Advances in Bioscience and Biotechnology, 11, 7–21 Jimenez-Krassel, F., Scheetz, D. M., Neuder, L. M., Pursley, J. R., Ireland, J. J.(2016). A single ultrasound determination of ≥ 25 follicles ≥ 3 mm in diameter in dairy heifers is predictive of a reduced productive herd life. Journal of Dairy Science,100,5019–5027 Santos, G. M. G. (2016). High numbers of antral follicles are positively associated with in vitro embryo production but not the conception rate for FTAI in Nelore cattle. Animal Reproduction Science, 165, 17–21 Silva-Santos, K. C. (2014). Antral follicle populations and embryo production in vitro and in vivo of Bos indicus-taurus donors from weaning to yearling ages. Reproduction in Domestic Animal, 49, 228–232 Moraes, F. L. Z., Morotti, F., Costa, C. B., Lunardelli, P. A., Seneda, M. M. (2019) Relationships between antral follicle count, body condition, and pregnancy rates afer timed-AI in Bos indicus cattle. Theriogenology, 136, 10–14 Morotti, F. (2018). Ovarian follicular dynamics and conception rate in Bos indicus cows with diferent antral follicle counts subjected to timed artifcial insemination. Animal Reproduction Science, 188, 170–177 Mossa, F. (2012). Low numbers of ovarian follicles ≥ 3mm in diameter are associated with low fertility in dairy cows. Journal of Dairy Science, 95, 2355–2361 Noseir, W.M. (2003) Ovarian Follicular Activity and Hormonal Profile during Estrous Cycle in Cows: The Development of 2 versus 3 Waves. Reproductive Biology and Endocrinology, 1, 50 Singh, J., Dominguez, M., Jaiswal, R., Adams, G. P. (2004) A simple ultrasound test to predict the super stimulatory response in cattle.Theriogenology, 62, 227–243 Vasconcelos, J.L.M., Sartori, R., Oliveira, H.N., Guenther, J.G., Wiltbank, M.C. (2001) Reduction in Size of the Ovulatory Follicle Reduces Subsequent Luteal Size and Pregnancy Rate. Theriogenology, 56, 307–314 Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-2926683","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":208085339,"identity":"e3f67c98-bb2a-4ab8-a76d-b307423f5481","order_by":0,"name":"Anupam Datta","email":"","orcid":"","institution":"Animal Resources Development Department , Government of Tripura, India","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Anupam","middleName":"","lastName":"Datta","suffix":""},{"id":208085340,"identity":"7081baa1-1b0d-4e84-b4b0-6ea5128de5f4","order_by":1,"name":"Anubha Baruah","email":"","orcid":"","institution":"Faculty of Veterinary Science Assam, AAU India","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Anubha","middleName":"","lastName":"Baruah","suffix":""},{"id":208085341,"identity":"26a599f8-b876-494e-ab78-858e1903af43","order_by":2,"name":"Arundhati Bora","email":"","orcid":"","institution":"Faculty of Veterinary Science , Khanapara AAU, Assam India","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Arundhati","middleName":"","lastName":"Bora","suffix":""},{"id":208085342,"identity":"5580ac52-ac00-4753-bc98-42d2f80fae40","order_by":3,"name":"Devojyoti Dutta","email":"","orcid":"","institution":"Faculty of Veterinary Science, Khanapara AAU Assam India","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Devojyoti","middleName":"","lastName":"Dutta","suffix":""},{"id":208085343,"identity":"6f30a630-0bdb-482a-80d6-026dee59c719","order_by":4,"name":"Jiten Goswami","email":"","orcid":"","institution":"Faculty of Veterinary Science , Khanapara, AAU, Assam","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Jiten","middleName":"","lastName":"Goswami","suffix":""},{"id":208085344,"identity":"15c16ee7-f5f5-4305-b1cf-1cfd58ae12be","order_by":5,"name":"Dipak Bhuiya","email":"","orcid":"","institution":"Faculty of Veterinary Sciences ,AAU Assam India","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Dipak","middleName":"","lastName":"Bhuiya","suffix":""},{"id":208085345,"identity":"b161b07d-d21b-4b0a-8c5f-6688285078ae","order_by":6,"name":"Sukanta Das","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA6ElEQVRIiWNgGAWjYFACNgjFz998AEhJyBCpJYGBQXLGsQSQFh7itRgcyDEAcQlrkZ+Rlvi58IcdA8OBM59f3aix4GFgP3x0Az4tBjfSDkvPSEhmYGzu3WadcwzoMJ60tBt4tUikN0jzJDAzMDOc3WacwwbUIsFjhleL/Iz05t88CfVAL+U8M875R4QWhhtpx4C2HAZ6O4f5cW4bEVoMzjxLs+ZJO84jIXHMjDm3T4KHjZBf5NvTjG/z2FTL2Z9vfvw551udHD/74WP4HQYFoOhgkwCx2IhRDgPMH0hRPQpGwSgYBSMHAAAqnEHJc01yRgAAAABJRU5ErkJggg==","orcid":"","institution":"College of Veterinary Sciences and Animal Husbandry,R.K.Nagar Tripura India","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Sukanta","middleName":"","lastName":"Das","suffix":""},{"id":208085346,"identity":"10002392-09a9-4e59-8157-6e60efd53836","order_by":7,"name":"Avishek Paul","email":"","orcid":"","institution":"Veterinary Officer, Animal Resources Development Department , Govt of Tripura India","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Avishek","middleName":"","lastName":"Paul","suffix":""}],"badges":[],"createdAt":"2023-05-12 08:45:00","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-2926683/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-2926683/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":38406095,"identity":"59d3b9fc-1b1b-47d1-96ca-8dca793d06a4","added_by":"auto","created_at":"2023-06-12 14:48:52","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":68637,"visible":true,"origin":"","legend":"\u003cp\u003ePhotograph of a female cyclic Lakhimi cattle of Assam\u003c/p\u003e","description":"","filename":"Fig1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-2926683/v1/ac0a2cf3692494a80cc288e3.jpg"},{"id":38407517,"identity":"31e87cb9-94dc-4078-9db1-17273b0c0970","added_by":"auto","created_at":"2023-06-12 14:56:52","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":15876,"visible":true,"origin":"","legend":"\u003cp\u003eFollicular dynamics of Lakhimi cow with two (a) and three (b)follicular \u0026nbsp;waves during estrous cycle\u003c/p\u003e","description":"","filename":"Picture2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-2926683/v1/b09de1d29f47e01e1b119b59.jpg"},{"id":38406094,"identity":"b3d5ffa4-eb62-48d6-9693-cecf1650533e","added_by":"auto","created_at":"2023-06-12 14:48:52","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":47605,"visible":true,"origin":"","legend":"\u003cp\u003eUltrasonographical images showing follicular development and ovarian \u0026nbsp;changes during estrous cycle in Lakhimi cows (a-small follciles, b \u0026nbsp;medium c-large d ovulatory follicle and e-Corpus luteum with blood \u0026nbsp;vessels)\u003c/p\u003e","description":"","filename":"Picture1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-2926683/v1/665cbfae6a317f2c3de64bff.jpg"},{"id":50203528,"identity":"09bb8763-b632-4576-9982-787d049a4da6","added_by":"auto","created_at":"2024-01-26 08:20:47","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":504228,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-2926683/v1/0f304d6a-c22e-4b34-8cfb-cadadabafc33.pdf"}],"financialInterests":"","formattedTitle":"Insight into ovarian follicular dynamics and hormonal interplay during estrus period in Lakhimi cow of Assam","fulltext":[{"header":"Introduction","content":"\u003cp\u003eIndia has 41 recognized indigenous breeds of cattle (ICAR-NBAGR, India) and the state of Assam possesses 8.4 million cattle out of which 7.9 million are indigenous (Source: Directorate of Animal Husbandry and Veterinary Department, Assam India). The indigenous cattle of Assam Lakhimi a small-sized, dual-purpose registered breed of India ((ICAR-NBAGR, India) have evolved through several generations of natural selection. The importance of these animals lies in their draught power capacity, heat tolerance, disease resistance, adaptability to harsh agro-climatic conditions, and ability to survive and perform under scarce feed and fodder.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe optimum reproductive rhythm of the animal within the normal physiological range is key to production and performance in cows. Understanding, the ovarian follicular interplay during the oestrus cycle is essential to interpret the reproductive behavior of this breed. Ovarian follicular dynamics in cows are characterized by follicular waves growth and regression during the estrous cycle (Savio et al. 1993; Knopf et al.1989) under the influence of serum FSH for recruitment of follicles (2 - 5 mm) to become dominant (Ginther et al.1996), the selection of dominant follicles, and regression of subordinate follicles (Fortune et al. 1993;2003). Bovine usually shows two (Knopf et al. 1989; Taylor et al. 1991) or three (Savio et al.1988; Sirois et al. 1988) follicular waves during the estrous cycle, but cycles with one (Savio et al.1988) or four (Sirois et al. 1988) follicular waves are also found. Bovine follicular wave is varied with the breed (Figueiredo et al.1997), reproductive stage (Roche et al.1991), season (Lucy et al.1992; energy balance (Rhodes et al.1995), and body score condition. The association of ovarian follicular number in bovine with high repeatability (Ireland et al. 2008; Morotti et al. 2015;2017; Zangirolamo et al. 2018; Seneda et al. 2019) and reproductive performance is reported by (Burns et al. 2005; Evans et al. 2012, Ireland et al. 2011; Jimenes et al. 2017; Santos et al. 2016; Silva-Santos et al. 2014; Morotti et al. 2018; Moraes et al. 2019; Moraes et al. 2019; Morotti et al. 2018; De Lima et al. 2020). However, the exact dynamics of follicular wave remain unknown at the breed level, individual level, and its influence on cattle fertility. Low numbers of antral follicles in female cattle have been associated with poor reproductive performance (Mossa et al. 2012), small ovaries and reduced endometrial thickness (Jaminez et al. 2009), poor embryo (Ireland et al. 2008; Singh et al. 2004).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe study of bovine follicular dynamics is not a new venture ( Savio et al.1993; Sunderland et al.1994; Bergfeld et al. 1994). It revealed many variations in timing, cycle patterns, and individuality (Ireland et al. 2008; Morotti et al. 2015;2017; Zangirolamo et al. 2018; Seneda et al. 2019; Burns et al. 2005; Evans et al. 2012; Ireland et al. 2011; Jimenez et al. 2016; Santos et al. 2016; Silva-Santos et al. 2014; Morotti et al. 2018; Moraes et al; 2019). Assam local cattle (Lakhimi) are such important in this agro-climatic region no such literature is available regarding the follicular dynamic study.\u003c/p\u003e\n\u003cp\u003eTo explore the reproductive potentials of the locally evolved Lakhimi cow of Assam it is very essential to investigate the reproductive rhythm and follicular dynamics along with the interplay of progesterone, estradiol, pituitary-dependant follicle-stimulating hormone (FSH), luteinizing hormone. \u0026nbsp;The study of follicular dynamics during the estrous cycle may help to clarify the phenomena that interfere in estrous synchronization and ovulation as well as in the ovarian response of superovulated animals and may improve fertility levels. (Bhosrekar et al. 2006).\u0026nbsp;\u003c/p\u003e"},{"header":"Materials And Methods","content":"\u003cp\u003e\u003cstrong\u003eEthical Permission:\u003c/strong\u003e The experiment was approved by the Institutional Ethical Committee Approval \u0026nbsp; 770/ac/CPCSEA/FVSc/AAU/IAEC/17-18/569\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eLocation of the experiment\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study was conducted at the Experimental animal shed, Department of Veterinary Physiology, College of Veterinary Science, AAU, Khanapara. RIA (Radio immune assay) was performed at NRL (Nuclear research laboratory), Department of Veterinary Physiology, College of Veterinary Science, AAU, Khanapara. ELISA was conducted at the Department of Veterinary Microbiology, College of Veterinary Science, AAU, Khanapara, Assam.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eExperimental animals and their management\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSix Assam local (Lakhimi) adult healthy cyclic cows, dewormed, routinely vaccinated (fig-1) with good body score condition, without any reproductive abnormalities were selected for the study. All the Lakhimi cows had regular estrous cycles and were confirmed non-pregnant by rectal palpation and ultrasonography before the study. All the experimental cows were housed together in well-ventilated hygienic sheds and maintained under the same conditions throughout the study with ad libitum clean drinking water and fodder.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePreparation of animals for ultrasonography\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe animal selected for ultrasonography was restrained in a standing position for scanning in the Travis, The area was prepared for darkness to observe the fine details of images for necessary interpretation.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eUltrasound scanning of the ovary:\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll cows were scanned by using a real-time, B-mode, ultrasound scanner (M turbo C, Fujifilm Sonosite Inc., Bothell, USA) equipped with a 7.5-9.0 MHz linear rectal transducer adapted for transrectal examination in large domestic animals. The ultrasound scanning was undertaken on lateromedial and dorsoventral planes to monitor ovarian follicular dynamics. Follicular measurements were recorded (length and width), throughout an estrous cycle starting from observed estrus (day 0) to subsequent standing estrus. The day-to-day identity of follicles was profiled as described by Tom et al. (1998). The number of follicles recruited (as evidenced by small 3-4 mm size follicles on the day of emergence) and the characteristics of the dominant follicles (DFs) during the first follicular wave (Wave I) and ovulatory wave were compared.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eVarious observations like follicular, luteal dimensions, development, and regression days, in different waves were recorded. Each ovary was scanned for the positions of the antral follicles and corpus luteum. Small follicles, medium, large, and ovulatory follicles (fig-3) were identified with diameters of - 3mm to 6mm, above 6mm to 9mm, above 9 mm, and more than 9 mm respectively.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eBlood samples and hormone assay:\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e5 ml blood samples were collected on every alternate day of an estrous cycle in heparinized tubes and placed on ice immediately after collection. Plasma was separated by centrifuging the blood sample at 1500 rpm for 15 minutes, within 30 minutes of blood collection, and transferred to cryovials and stored at -20˚c until assayed for hormones.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEstimation of hormone:\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe concentration of P4 was measured with a solid phase RIA kit (Progesterone C.T. RIA kit (Pkg: 100 T) Batch No 181008D, M/s Beckman Coulter; supplied by M/S Anand brothers New Delhi) and the radioactivity was counted in a 125I (STRATEC Germany) gamma counter. Serum Estradiol and LH assay employs the competitive enzyme immunoassay technique. The microtiter plate provided in this kit has been pre-coated with E2 and LH antibodies.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eStatistical analysis was performed by Independent Sample T- test using SPSS\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eThe estrous cycle of the Lakhimi cow evaluated in this study presented the characteristic pattern of follicular growth and waves, initial development of a group of \u0026ge; 3 mm follicles in each wave, followed by selection, development, and atresia of a dominant anovulatory follicle or ovulation of ovulatory dominant follicle. Two patterns (two and three) of follicular development were detected during twelve estrous cycles of the Lakhimi cows that were monitored. Lakhimi cows have a predominance of the estrous cycle with two follicular waves (66%).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn the two-wave cycle (fig-2a), the first and second wave emerged on day 1.16 \u0026plusmn; 0.30 and 10.83 \u0026plusmn; 0.47 of the cycle and was followed by selection (divergence) of DF on day 5.5 \u0026plusmn; 0.42 and 14.83 \u0026plusmn; 0.60 of the cycle while in three wave cycle (fig-2b, table-1), first, second and third wave emerged on day 0.83 \u0026plusmn; 0.16, 7.33 \u0026plusmn; 0.49 and 12.16 \u0026plusmn; 0.47 of the cycle and was followed by selection (divergence) of DF on day 4.83 \u0026plusmn; 0.30, 9.16 \u0026plusmn; 0.31 and 15.5 \u0026plusmn;0.5. The divergence of follicles is defined as the difference in growth rates between the two larger follicles and is marked by the continued development of the largest follicle but a decline or stop in the growth of others (Table-1,2).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn two wave estrous cycle, 3.5 \u0026plusmn; 0.42 and 4.33 \u0026plusmn; 0.49 number of follicles (\u0026gt;3 mm) emerged at the first and second wave emergence while in three wave cycles 3.83 \u0026plusmn; 0.47, 2.83 \u0026plusmn; 0.30 and 3.66 \u0026plusmn; 0.33 number of follicles (\u0026gt;3 mm) emerged at first, second and third wave emergence in Lakhimi cows (Table-1,3). The maximum size of the DF of the first and second follicular wave in two wave estrous cycles was 8.49 \u0026plusmn; 0.49 and 11.51 \u0026plusmn; 0.54 mm on a mean day was 6.83 \u0026plusmn; 0.40 and 20.16 \u0026plusmn; 0.30 while the maximum size of the DF of the first, second and third follicular wave in three wave cycle was 9.41 \u0026plusmn; 0.87, 8.51 \u0026plusmn; 0.26 and 12.41 \u0026plusmn; 0.69 mm on the mean day 6.16 \u0026plusmn; 0.47, 15.5 \u0026plusmn; 0.56 and 20.33 \u0026plusmn; 0.33 in Lakhimi cows (Table-2,4). First-wave DF reached its maximum size during the luteal phase, it persisted for 3-6 days and then underwent atresia while second-wave DF reached its maximum size during luteal regression and ovulated. The first wave dominant follicle of the two waves estrous cycle underwent atresia on the mean (\u0026plusmn;SE) day 8.83 \u0026plusmn; 0.30 whereas in three wave cycle first and second wave dominant follicles underwent atresia on the mean (\u0026plusmn; SE) day 7.83 \u0026plusmn; 0.30 and 15.16 \u0026plusmn; 0.40 in Lakhimi cows. In two-wave cycles, ovulation occurred on the mean (\u0026plusmn; SE) day 20.16 \u0026plusmn; 0.30 whereas in three wave cycle, ovulation occurred on the mean (\u0026plusmn; SE) day 20.33 \u0026plusmn; 0.33. Time of ovulation may be variable because these studies were done on a day basis, so there may be chances of biases in the detection time of the start of overt signs of estrus. In two wave estrous cycle, the first and second waves persisted for 14.33 \u0026plusmn; 0.55 and 10.66 \u0026plusmn; 0.49 days whereas, in three wave cycle first, second and third waves persisted for 14.16 \u0026plusmn; 0.40, 11.83 \u0026plusmn; 0.60, and 7.16 \u0026plusmn; 0.47 days (Table-3,4).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eHormonal profiles during the estrous cycle of Lakhimi cows\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe concentration of progesterone (ng/ml) was found highest in cows up to day 10 of the estrous cycle (10.94 \u0026plusmn;1.93) and declined towards the end of the cycle up to the next estrus. In the present study, serum progesterone levels ranged from 0.41 to 1.54 ng/ml during the follicular phase and between 3.52 to 10.94 ng/ml during the luteal phase. The level of estradiol was highest on the day before estrus (day 20) and on the day of heat (day 0) during the estrous cycle (192\u0026plusmn;11.35) and day 20 (118\u0026plusmn;13.81). However, the level of estradiol was maintained very low on other days of the estrous cycle. The serum LH (ng/ml) level of the Lakhimi cow was found highest on day 1 of the estrous cycle (7.97\u0026plusmn;1.03). The LH level however was maintained at a very low concentration on other days of the estrous cycle in both the group of animals (table-5). \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTable No-1\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eD\u003c/strong\u003e\u003cstrong\u003eifferent ovarian follicular of characteristics (mean\u0026plusmn;se) of two wave cycle in \u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eL\u003c/strong\u003e\u003cstrong\u003eakhimi cows\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"575\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"40.34782608695652%\" rowspan=\"2\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eCharacteristics\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"59.65217391304348%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eFollicular Waves\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"51.75438596491228%\" valign=\"top\"\u003e\n \u003cp\u003e1\u003csup\u003est\u003c/sup\u003e (Anovulatory)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"48.24561403508772%\" valign=\"top\"\u003e\n \u003cp\u003e2\u003csup\u003end\u003c/sup\u003e (Ovulatory)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"40.41811846689895%\" valign=\"top\"\u003e\n \u003cp\u003eDay of Wave emergence\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"30.83623693379791%\" valign=\"top\"\u003e\n \u003cp\u003e1.16\u0026plusmn;0.30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.745644599303137%\" valign=\"top\"\u003e\n \u003cp\u003e10.83\u0026plusmn;0.47\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"40.41811846689895%\" valign=\"top\"\u003e\n \u003cp\u003eNo. of Follicles (\u0026gt;3mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"30.83623693379791%\" valign=\"top\"\u003e\n \u003cp\u003e3.5\u0026plusmn;0.42\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.745644599303137%\" valign=\"top\"\u003e\n \u003cp\u003e4.33\u0026plusmn;0.49\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"40.41811846689895%\" valign=\"top\"\u003e\n \u003cp\u003eDay of emergence of DF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"30.83623693379791%\" valign=\"top\"\u003e\n \u003cp\u003e5.5\u0026plusmn;0.42\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.745644599303137%\" valign=\"top\"\u003e\n \u003cp\u003e14.83\u0026plusmn;0.60\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"40.41811846689895%\" valign=\"top\"\u003e\n \u003cp\u003eMaximum diameter of DF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"30.83623693379791%\" valign=\"top\"\u003e\n \u003cp\u003e8.49\u0026plusmn;0.49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.745644599303137%\" valign=\"top\"\u003e\n \u003cp\u003e11.51\u0026plusmn;0.54\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"40.41811846689895%\" valign=\"top\"\u003e\n \u003cp\u003eDay of maximum diameter\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"30.83623693379791%\" valign=\"top\"\u003e\n \u003cp\u003e6.83\u0026plusmn;0.40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.745644599303137%\" valign=\"top\"\u003e\n \u003cp\u003e20.16\u0026plusmn;0.30\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"40.41811846689895%\" valign=\"top\"\u003e\n \u003cp\u003eDay of onset of atresia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"30.83623693379791%\" valign=\"top\"\u003e\n \u003cp\u003e8.83\u0026plusmn;0.30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.745644599303137%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"40.41811846689895%\" valign=\"top\"\u003e\n \u003cp\u003eDay of termination of wave\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"30.83623693379791%\" valign=\"top\"\u003e\n \u003cp\u003e13.66\u0026plusmn;0.42\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.745644599303137%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"40.41811846689895%\" valign=\"top\"\u003e\n \u003cp\u003eDuration of persistence of wave (days)\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"30.83623693379791%\" valign=\"top\"\u003e\n \u003cp\u003e14.33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.745644599303137%\" valign=\"top\"\u003e\n \u003cp\u003e10.66\u0026plusmn;0.49\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eTable No-2\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eT\u003c/strong\u003e\u003cstrong\u003ehe mean\u0026plusmn;se of the follicle diameter (mm) at different days in two wave cycle in\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eL\u003c/strong\u003e\u003cstrong\u003eakhimi cows\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"574\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.790940766550523%\" valign=\"top\"\u003e\n \u003cp\u003eDays of estrous cycle\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"36.23693379790941%\" valign=\"top\"\u003e\n \u003cp\u003e1\u003csup\u003est\u003c/sup\u003e Follicular wave\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.97212543554007%\" valign=\"top\"\u003e\n \u003cp\u003e2\u003csup\u003end\u003c/sup\u003e Follicular wave\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.790940766550523%\" valign=\"top\"\u003e\n \u003cp\u003eDay 0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"36.23693379790941%\" valign=\"top\"\u003e\n \u003cp\u003e4.2000\u0026plusmn;0.44721\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.97212543554007%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.790940766550523%\" valign=\"top\"\u003e\n \u003cp\u003eDay 2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"36.23693379790941%\" valign=\"top\"\u003e\n \u003cp\u003e5.3000\u0026plusmn;0.49193\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.97212543554007%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.790940766550523%\" valign=\"top\"\u003e\n \u003cp\u003eDay 4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"36.23693379790941%\" valign=\"top\"\u003e\n \u003cp\u003e6.0117\u0026plusmn;0.48666\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.97212543554007%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.790940766550523%\" valign=\"top\"\u003e\n \u003cp\u003eDay 6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"36.23693379790941%\" valign=\"top\"\u003e\n \u003cp\u003e8.4967\u0026plusmn;0.49165\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.97212543554007%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.790940766550523%\" valign=\"top\"\u003e\n \u003cp\u003eDay 8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"36.23693379790941%\" valign=\"top\"\u003e\n \u003cp\u003e5.6950\u0026plusmn;0.53762\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.97212543554007%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.790940766550523%\" valign=\"top\"\u003e\n \u003cp\u003eDay 10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"36.23693379790941%\" valign=\"top\"\u003e\n \u003cp\u003e6.3983 \u0026plusmn; 0.59200\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.97212543554007%\" valign=\"top\"\u003e\n \u003cp\u003e4.4983 \u0026plusmn; 0.63518\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.790940766550523%\" valign=\"top\"\u003e\n \u003cp\u003eDay 12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"36.23693379790941%\" valign=\"top\"\u003e\n \u003cp\u003e4.3117 \u0026plusmn; 0.60159\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.97212543554007%\" valign=\"top\"\u003e\n \u003cp\u003e6.1950 \u0026plusmn; 0.40261\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.790940766550523%\" valign=\"top\"\u003e\n \u003cp\u003eDay 14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"36.23693379790941%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.97212543554007%\" valign=\"top\"\u003e\n \u003cp\u003e8.8100 \u0026plusmn; 0.52472\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.790940766550523%\" valign=\"top\"\u003e\n \u003cp\u003eDay 16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"36.23693379790941%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.97212543554007%\" valign=\"top\"\u003e\n \u003cp\u003e8.9950 \u0026plusmn; 0.53611\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.790940766550523%\" valign=\"top\"\u003e\n \u003cp\u003eDay 18\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"36.23693379790941%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.97212543554007%\" valign=\"top\"\u003e\n \u003cp\u003e9.4950 \u0026plusmn; 0.58092\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.790940766550523%\" valign=\"top\"\u003e\n \u003cp\u003eDay 20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"36.23693379790941%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.97212543554007%\" valign=\"top\"\u003e\n \u003cp\u003e11.2200 \u0026plusmn; 0.68172\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.790940766550523%\" valign=\"top\"\u003e\n \u003cp\u003eDay 21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"36.23693379790941%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.97212543554007%\" valign=\"top\"\u003e\n \u003cp\u003e11.5117 \u0026plusmn; 0.54980\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003cstrong\u003eTable: 3. O\u003c/strong\u003e\u003cstrong\u003evarian follicular characteristics (mean\u0026plusmn;se) of three wave cycle in\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eL\u003c/strong\u003e\u003cstrong\u003eakhimi cows\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"577\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"41.34948096885813%\" rowspan=\"2\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eCharacteristics\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"58.65051903114187%\" colspan=\"3\" valign=\"top\"\u003e\n \u003cp\u003eFollicular Waves\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.49852507374631%\" valign=\"top\"\u003e\n \u003cp\u003e1\u003csup\u003est\u003c/sup\u003e (Anovulatory)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.92330383480826%\" valign=\"top\"\u003e\n \u003cp\u003e2\u003csup\u003end\u003c/sup\u003e Anovulatory)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"36.57817109144543%\" valign=\"top\"\u003e\n \u003cp\u003e3\u003csup\u003erd\u003c/sup\u003e (Ovulatory)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"41.34948096885813%\" valign=\"top\"\u003e\n \u003cp\u003eDay of Wave emergence\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.301038062283737%\" valign=\"top\"\u003e\n \u003cp\u003e0.83 \u0026plusmn; 0.16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.896193771626297%\" valign=\"top\"\u003e\n \u003cp\u003e7.33 \u0026plusmn; 0.49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.453287197231834%\" valign=\"top\"\u003e\n \u003cp\u003e12.16 \u0026plusmn; 0.47\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"41.34948096885813%\" valign=\"top\"\u003e\n \u003cp\u003eNo. Of Follicles (\u0026gt;3mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.301038062283737%\" valign=\"top\"\u003e\n \u003cp\u003e3.83 \u0026plusmn; 0.47\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.896193771626297%\" valign=\"top\"\u003e\n \u003cp\u003e2.83 \u0026plusmn; 0.30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.453287197231834%\" valign=\"top\"\u003e\n \u003cp\u003e3.66 \u0026plusmn; 0.33\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"41.34948096885813%\" valign=\"top\"\u003e\n \u003cp\u003eDay of emergence of DF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.301038062283737%\" valign=\"top\"\u003e\n \u003cp\u003e4.83 \u0026plusmn; 0.30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.896193771626297%\" valign=\"top\"\u003e\n \u003cp\u003e9.16 \u0026plusmn; 0.31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.453287197231834%\" valign=\"top\"\u003e\n \u003cp\u003e15.5 \u0026plusmn;0.5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"41.34948096885813%\" valign=\"top\"\u003e\n \u003cp\u003eMaximum diameter of DF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.301038062283737%\" valign=\"top\"\u003e\n \u003cp\u003e9.41 \u0026plusmn; 0.87\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.896193771626297%\" valign=\"top\"\u003e\n \u003cp\u003e8.51 \u0026plusmn; 0.26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.453287197231834%\" valign=\"top\"\u003e\n \u003cp\u003e12.41 \u0026plusmn; 0.69\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"41.34948096885813%\" valign=\"top\"\u003e\n \u003cp\u003eDay of maximum diameter\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.301038062283737%\" valign=\"top\"\u003e\n \u003cp\u003e6.16 \u0026plusmn; 0.47\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.896193771626297%\" valign=\"top\"\u003e\n \u003cp\u003e15.5 \u0026plusmn; 0.56\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.453287197231834%\" valign=\"top\"\u003e\n \u003cp\u003e20.33 \u0026plusmn; 0.33\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"41.34948096885813%\" valign=\"top\"\u003e\n \u003cp\u003eDay of onset of atresia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.301038062283737%\" valign=\"top\"\u003e\n \u003cp\u003e7.83 \u0026plusmn; 0.30\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.896193771626297%\" valign=\"top\"\u003e\n \u003cp\u003e15.16 \u0026plusmn; 0.40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.453287197231834%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"41.34948096885813%\" valign=\"top\"\u003e\n \u003cp\u003eDay of termination of wave\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.301038062283737%\" valign=\"top\"\u003e\n \u003cp\u003e14.33 \u0026plusmn; 0.42\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.896193771626297%\" valign=\"top\"\u003e\n \u003cp\u003e19.16 \u0026plusmn; 0.47\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.453287197231834%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"41.34948096885813%\" valign=\"top\"\u003e\n \u003cp\u003eDuration of persistence of wave (days)\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.301038062283737%\" valign=\"top\"\u003e\n \u003cp\u003e14.16 \u0026plusmn; 0.40 \u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.896193771626297%\" valign=\"top\"\u003e\n \u003cp\u003e11.83 \u0026plusmn; 0.60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.453287197231834%\" valign=\"top\"\u003e\n \u003cp\u003e7.16 \u0026plusmn; 0.47\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003cstrong\u003eTable : 4 Mean\u0026plusmn;SEof the follicle diameter (mm) at different days in three wave cycle\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"571\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.54385964912281%\" valign=\"top\"\u003e\n \u003cp\u003eDays of estrous cycle\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.68421052631579%\" valign=\"top\"\u003e\n \u003cp\u003e1\u003csup\u003est\u003c/sup\u003e Follicular wave\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.385964912280702%\" valign=\"top\"\u003e\n \u003cp\u003e2\u003csup\u003end\u003c/sup\u003e Follicular wave\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.385964912280702%\" valign=\"top\"\u003e\n \u003cp\u003e3\u003csup\u003erd\u003c/sup\u003e Follicular wave\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.54385964912281%\" valign=\"top\"\u003e\n \u003cp\u003eDay 0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.68421052631579%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.385964912280702%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.385964912280702%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.54385964912281%\" valign=\"top\"\u003e\n \u003cp\u003eDay 2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.68421052631579%\" valign=\"top\"\u003e\n \u003cp\u003e4.3117 \u0026plusmn; 0.43593\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.385964912280702%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.385964912280702%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.54385964912281%\" valign=\"top\"\u003e\n \u003cp\u003eDay 4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.68421052631579%\" valign=\"top\"\u003e\n \u003cp\u003e5.8450 \u0026plusmn; 0.91365\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.385964912280702%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.385964912280702%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.54385964912281%\" valign=\"top\"\u003e\n \u003cp\u003eDay 6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.68421052631579%\" valign=\"top\"\u003e\n \u003cp\u003e9.4117 \u0026plusmn; 0.87254\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.385964912280702%\" valign=\"top\"\u003e\n \u003cp\u003e3.5067 \u0026plusmn; 0.47532\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.385964912280702%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.54385964912281%\" valign=\"top\"\u003e\n \u003cp\u003eDay 8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.68421052631579%\" valign=\"top\"\u003e\n \u003cp\u003e9.2283 \u0026plusmn; 0.54345\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.385964912280702%\" valign=\"top\"\u003e\n \u003cp\u003e4.6283 \u0026plusmn; 0.49127\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.385964912280702%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.54385964912281%\" valign=\"top\"\u003e\n \u003cp\u003eDay 10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.68421052631579%\" valign=\"top\"\u003e\n \u003cp\u003e6.2317 \u0026plusmn; 0.54287\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.385964912280702%\" valign=\"top\"\u003e\n \u003cp\u003e5.7117 \u0026plusmn; 0.56724\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.385964912280702%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.54385964912281%\" valign=\"top\"\u003e\n \u003cp\u003eDay 12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.68421052631579%\" valign=\"top\"\u003e\n \u003cp\u003e4.1450 \u0026plusmn; 0.55115\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.385964912280702%\" valign=\"top\"\u003e\n \u003cp\u003e7.3283 \u0026plusmn; 0.60960\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.385964912280702%\" valign=\"top\"\u003e\n \u003cp\u003e4.0483 \u0026plusmn; 0.46914\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.54385964912281%\" valign=\"top\"\u003e\n \u003cp\u003eDay 14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.68421052631579%\" valign=\"top\"\u003e\n \u003cp\u003e3.0083 \u0026plusmn; 0.70524\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.385964912280702%\" valign=\"top\"\u003e\n \u003cp\u003e7.7300 \u0026plusmn; 0.38221\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.385964912280702%\" valign=\"top\"\u003e\n \u003cp\u003e6.5283 \u0026plusmn; 0.77125\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.54385964912281%\" valign=\"top\"\u003e\n \u003cp\u003eDay 16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.68421052631579%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.385964912280702%\" valign=\"top\"\u003e\n \u003cp\u003e8.5167 \u0026plusmn; 0.26594\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.385964912280702%\" valign=\"top\"\u003e\n \u003cp\u003e7.8133 \u0026plusmn; 0.78803\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.54385964912281%\" valign=\"top\"\u003e\n \u003cp\u003eDay 18\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.68421052631579%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.385964912280702%\" valign=\"top\"\u003e\n \u003cp\u003e7.5267 \u0026plusmn; 0.82291\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.385964912280702%\" valign=\"top\"\u003e\n \u003cp\u003e9.3967 \u0026plusmn; 0.58485\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.54385964912281%\" valign=\"top\"\u003e\n \u003cp\u003eDay 20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.68421052631579%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.385964912280702%\" valign=\"top\"\u003e\n \u003cp\u003e4.8133 \u0026plusmn; 0.44034\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.385964912280702%\" valign=\"top\"\u003e\n \u003cp\u003e11.8017 \u0026plusmn; 0.59335\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.54385964912281%\" valign=\"top\"\u003e\n \u003cp\u003eDay 21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.68421052631579%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.385964912280702%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.385964912280702%\" valign=\"top\"\u003e\n \u003cp\u003e12.4150 \u0026plusmn; 0.69786\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eTABLE\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e5\u003c/strong\u003e\u003cstrong\u003e:\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eS\u003c/strong\u003e\u003cstrong\u003eerum progesterone\u003c/strong\u003e\u003cstrong\u003e, estradiol and LH\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;(ng/ml) profile (mean\u0026plusmn;se) in\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;L\u003c/strong\u003e\u003cstrong\u003eakhimi cows\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cdiv\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"580\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"20.689655172413794%\" valign=\"top\"\u003e\n \u003cp\u003eDays of estrous cycle\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.551724137931036%\" valign=\"top\"\u003e\n \u003cp\u003eMaen concentration of Serum progesterone (ng/ml)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.20689655172414%\" valign=\"top\"\u003e\n \u003cp\u003eMaen concentration of Serum\u0026nbsp;estradiol\u0026nbsp;(ng/ml)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.551724137931036%\" valign=\"top\"\u003e\n \u003cp\u003eMaen concentration of Serum\u0026nbsp;LH\u0026nbsp;(ng/ml)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"20.689655172413794%\" valign=\"top\"\u003e\n \u003cp\u003eDay 0\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.551724137931036%\" valign=\"top\"\u003e\n \u003cp\u003e0.41\u0026plusmn;0.09\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.20689655172414%\" valign=\"top\"\u003e\n \u003cp\u003e192\u0026plusmn;11.35\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.551724137931036%\" valign=\"top\"\u003e\n \u003cp\u003e2.61\u0026plusmn;0.53\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"20.689655172413794%\" valign=\"top\"\u003e\n \u003cp\u003eDay 1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.551724137931036%\" valign=\"top\"\u003e\n \u003cp\u003e0.43\u0026plusmn;0.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.20689655172414%\" valign=\"top\"\u003e\n \u003cp\u003e29\u0026plusmn;3.03\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.551724137931036%\" valign=\"top\"\u003e\n \u003cp\u003e7.97\u0026plusmn;1.03\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"20.689655172413794%\" valign=\"top\"\u003e\n \u003cp\u003eDay 2\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.551724137931036%\" valign=\"top\"\u003e\n \u003cp\u003e0.56\u0026plusmn;0.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.20689655172414%\" valign=\"top\"\u003e\n \u003cp\u003e28\u0026plusmn;2.79\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.551724137931036%\" valign=\"top\"\u003e\n \u003cp\u003e1.85\u0026plusmn;0.41\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"20.689655172413794%\" valign=\"top\"\u003e\n \u003cp\u003eDay 4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.551724137931036%\" valign=\"top\"\u003e\n \u003cp\u003e4.63\u0026plusmn;0.54\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.20689655172414%\" valign=\"top\"\u003e\n \u003cp\u003e25\u0026plusmn;0.44\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.551724137931036%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;1.82\u0026plusmn;0.41\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"20.689655172413794%\" valign=\"top\"\u003e\n \u003cp\u003eDay 6\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.551724137931036%\" valign=\"top\"\u003e\n \u003cp\u003e7.69\u0026plusmn;1.43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.20689655172414%\" valign=\"top\"\u003e\n \u003cp\u003e20\u0026plusmn;1.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.551724137931036%\" valign=\"top\"\u003e\n \u003cp\u003e0.91\u0026plusmn;0.20\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"20.689655172413794%\" valign=\"top\"\u003e\n \u003cp\u003eDay 8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.551724137931036%\" valign=\"top\"\u003e\n \u003cp\u003e8.92\u0026plusmn;1.43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.20689655172414%\" valign=\"top\"\u003e\n \u003cp\u003e25\u0026plusmn;1.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.551724137931036%\" valign=\"top\"\u003e\n \u003cp\u003e0.91\u0026plusmn;0.20\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"20.689655172413794%\" valign=\"top\"\u003e\n \u003cp\u003eDay 10\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.551724137931036%\" valign=\"top\"\u003e\n \u003cp\u003e10.94\u0026plusmn;1.93\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.20689655172414%\" valign=\"top\"\u003e\n \u003cp\u003e21\u0026plusmn;1.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.551724137931036%\" valign=\"top\"\u003e\n \u003cp\u003e0.79\u0026plusmn;0.09\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"20.689655172413794%\" valign=\"top\"\u003e\n \u003cp\u003eDay 12\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.551724137931036%\" valign=\"top\"\u003e\n \u003cp\u003e10.34\u0026plusmn;0.93\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.20689655172414%\" valign=\"top\"\u003e\n \u003cp\u003e15\u0026plusmn;1.58\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.551724137931036%\" valign=\"top\"\u003e\n \u003cp\u003e0.67\u0026plusmn;0.09\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"20.689655172413794%\" valign=\"top\"\u003e\n \u003cp\u003eDay 14\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.551724137931036%\" valign=\"top\"\u003e\n \u003cp\u003e7.77\u0026plusmn;1.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.20689655172414%\" valign=\"top\"\u003e\n \u003cp\u003e12\u0026plusmn;1.24\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.551724137931036%\" valign=\"top\"\u003e\n \u003cp\u003e0.54\u0026plusmn;0.09\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"20.689655172413794%\" valign=\"top\"\u003e\n \u003cp\u003eDay 16\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.551724137931036%\" valign=\"top\"\u003e\n \u003cp\u003e3.52\u0026plusmn;0.67\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.20689655172414%\" valign=\"top\"\u003e\n \u003cp\u003e12\u0026plusmn;1.44\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.551724137931036%\" valign=\"top\"\u003e\n \u003cp\u003e0.78\u0026plusmn;0.12\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"20.689655172413794%\" valign=\"top\"\u003e\n \u003cp\u003eDay 18\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.551724137931036%\" valign=\"top\"\u003e\n \u003cp\u003e1.54\u0026plusmn;0.40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.20689655172414%\" valign=\"top\"\u003e\n \u003cp\u003e79\u0026plusmn;9.18\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.551724137931036%\" valign=\"top\"\u003e\n \u003cp\u003e1.01\u0026plusmn;0.12\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"20.689655172413794%\" valign=\"top\"\u003e\n \u003cp\u003eDay 20\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.551724137931036%\" valign=\"top\"\u003e\n \u003cp\u003e0.71\u0026plusmn;0.14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.20689655172414%\" valign=\"top\"\u003e\n \u003cp\u003e118\u0026plusmn;13.81\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.551724137931036%\" valign=\"top\"\u003e\n \u003cp\u003e1.52\u0026plusmn;0.14\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eFollicular wave cycles in general (2-3) with the predominance of two follicular waves (66%) were recorded in Lakhimi cows. Similar observations were also recorded by many authors (Nelore cow- Figueiredo et al.1997; Crossbred cows- Filho et al. 2001; Crossbred cows- Alves et al. 2002; European cows \u0026ndash; Burns et al. 2005 and Rathi cows \u0026ndash; Gaur et al. 2007; Islam et al. 2020 in Red Chittagong cows). However, cycles with three follicular waves were also observed in indigenous Zebu cattle by Gambini et al. (1998). No cycle was observed with four or more follicular waves during the present study. Viana et al. (2000) recorded a small proportion of cows showing four and five follicular waves during the estrous cycle in Gir cows.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eFactors like the length of the luteal phase (Figueiredo et al. 1997), follicular size, estradiol concentration (Nosier et al. 2003), peaks of FSH (Adams et al. 2008) and IGF (Alveraz et al. 2000) may have an important role in determining waves of the follicle during the estrous cycle. Before the rise of a follicular wave peaks of FSH occur, and the number of peaks is related to the number of follicular developments in cows (Adams et al. 2008).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn the present study, in the two-wave cycle, the emergence of the first and second wave can be compared with those of Bahaman heifers on Day 0.2 \u0026plusmn; 0.1 and Day 10.0 \u0026plusmn; 0.4 (Rhodes et al. 1995) and Day 1.50 \u0026plusmn; 0.15 and 12.0 \u0026plusmn; 0.91 in Nelore cattle (Figueiredo et al.1997). However, Islam et al. (2020) reported 2.00 \u0026plusmn; 1.50 and 12.00 \u0026plusmn; 2.10 days respectively in two wave cycles in Red Chittagong cows.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Follicular wave lengths during 1st and 2nd waves in Lakhimi cows were delayed compared to Red Chittagong cows (Islam et al. 2020) on 12.44 \u0026plusmn; 0.08 and 8.07 \u0026plusmn; 0.06 days but concomitant to Nelore cattle on day 14.75 \u0026plusmn; 0.70 and 9.05 \u0026plusmn; 0.69 (Figueiredo et al. 1997) respectively. The three wave cycles in Lakhimi cows were similar to Zebu cows (Viana et al. 2000) and crossbred cows (Jaiswal et al. 2007; Filho et al. 2001). The variations in the persistence of waves in different breeds may be influenced by the pulsatile frequency of LH (Lucy et al. 1992), and progesterone (Gambini et al.1998).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn the present study the day of emergence, followed by selection (divergence) of DF in Lakhimi cows were correspondent to observations by Figueiredo et al. (1997) in Nellore cows; Gir (Gambini et al. 1998); crossbred (Filho et al. 2001; Jaiswal et al. 2007).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe presence of more numbers of ovarian follicles (\u0026gt;3mm) in two waves estrous cycle than in the three waves in the Lakhimi cow were in correspond to the Sirois et al. (1988z) in Holstein heifer, Alvarez et al. (2000) in Brahman cows, Amrozi et al. (2004) in Holstein cows and Jaiswal et al. (2007) in Crossbred cows. However, Islam et al. (2020) reported 8.00 \u0026plusmn; 1.50 and 6.50 \u0026plusmn; 1.70 numbers of follicles in Red Chittagong Cows. Variations in the number of follicles reported may be due to individual differences (Boni et al.1997), serum growth hormone, and IGF-I (Lucy et al.1992; Gong et al.1996) concentration. Season (Lammoglia et al.1998) and nutrition status (Lucy et al.1992) of cow. The ovarian antral follicular count is an important indicator of fertility and the number of follicles varies with breed, ovarian dimension, heritability, and size of the dominant follicle (Lima et al. 2020).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;The maximum size of the DF of the first and second follicular waves was smaller (8.49 \u0026plusmn; 0.49 and 11.51 \u0026plusmn; 0.54 mm) than in Red Chittagong cows (10-11 mm) (Islam et al. 2020), Nelore heifers (10 - 12 mm) (Figueiredo et al. 1997), Holstein heifers (14 - 20 mm), Brahman heifers (13 - 18 mm) (Rhodes et al. 1995) and similar to the DF (8 - 9 mm) reported for Chinese Yellow Cattle (Vasconcelos et al. 2001). However, the maximum diameter of DF during three follicular waves in Lakhimi cows was in agreement with the observations made by Gambini et al. (1998) in Gir and Nellore cows, Gaur et al. 2007 in Rathi cows) and Filho et al. (2001) in crossbred cows. Though the pattern of growth and turnover of DF were similar to Nellore, and Brahman cows but the sizes of DF in the ovaries of Lakhimi cows can be compared with Red Chittagong Cow but smaller than those of Nelore and Brahman heifers and Holstein.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn the present study, DF reached maximum size during the luteal phase, it persisted for 3-6 days and then underwent atresia while second wave DF reached its maximum size during luteal regression and ovulated. This finding matches the reports on Rathi cows by Gaur et al. (2007), Zebu cows by Viana et al. (2000), and crossbred cows by Filho et al. (2001). The difference in attaining a maximum diameter of DF may be because the second wave emerges during the period of higher progesterone production by the CL, whereas the first and third waves emerge respectively during the luteogenic and luteolytic periods (Viana et al. 2000; Gambini et al. 1998). during first follicular wave due to low concentration of progesterone, satisfactory negative feedback can not be generated on hypothalamic-pituitary to prevent the release of luteinizing hormone. The second wave started in the presence of fully formed CL that secretes a high concentration of progesterone, sufficient to inhibit the release of LH. Low-frequency pulses of LH were observed during the luteogenic and luteal phases of the estrous cycle, leading to regression of the DF and initiation of a new follicular wave (Gambini et al.1998). The third wave coincides with the reduced secretion of progesterone by the CL, resulting in an increased frequency of pulses of LH to a peak. This phase is to check the rapid follicular growth and ovulation (Savio et al.1993). The lower concentration of progesterone present during luteogenic and luteolytic periods may be associated with higher gonadotrophic concentration and consequently with higher diameter and persistency of DFs. Maximum size of the wave DF is proportional to the FSH release inhibition (Ginther et al.1996) but the final maturation and ovulation of DF are dependent on a high frequency of LH pulses (Roche et al. 1991). Nutritional status also influences the follicular dynamics during the estrous cycle. Maximum diameter and persistence of DF reduced in case of negative energy balance (Rhodes et al.1995).\u003c/p\u003e\n\u003cp\u003eThe mean day of follicular atresia in Lakhimi cows was in agreement with the findings by Ginther et al. (1996) in Holstein cows, Jaiswal et al. (2007) in crossbred cows, and Gaur et al.(2007) in Rathi cows. The day of ovulation accounted in the present study for two and three waves is in agreement with Gambini et al. (1998) in Gir and Nelore cows, Pinheiro et al. (1998) in European cows. Time of ovulation may be variable because these studies were done daily, so there may be chances of biases in the detection time of the start of overt signs of estrus.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe duration of growth of ovulatory follicle (OF) in Lakhimi cows can be comparable with two follicular wave cycles of Red Chittagong cows (8.24 \u0026plusmn; 0.56 and 9.51 \u0026plusmn; 0.68 days) Islam et al. (2020), Nelore cattle with two and three follicular wave cycles (8.65 \u0026plusmn; 0.73 and 7.0 \u0026plusmn; 0.51 days) Figueiredo et al. (1997) and Holstein heifers with two and three follicular waves cycles (7.50 \u0026plusmn; 0.19 and 5.90 \u0026plusmn; 0.30 days). Slower rates of follicular growth were recorded compared to those of Nelore cattle and Holstein heifers, which may be a breed variation. The follicular deviation after ovulation in Lakhimi cows in the present study during the two and three-wave cycle was approximately 2 days and Islam et al. (2020) reported 1.53 days in Red Chittagong cows. The emergence of the first follicular wave does not usually occur until 24 h after ovulation in Lakhimi Cow therefore, follicular deviation seems to occur earlier than in Nelore and Holstein females. (Fortune et al. 2003)\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Hormonal profile in Lakhimi Cows concerning follicular dynamics.\u003c/p\u003e\n\u003cp\u003eThe peak progesterone (ng/ml) concentration on the 10th day of the estrous cycle was followed by a decline towards the end of the cycle up to the next heat/estrus with a range from 0.41 to 1.54 ng/ml during the follicular phase and 3.52 to 10.94 ng/ml during luteal phase of the estrous cycle in Lakhimi cows. A similar trend of progesterone levels during the estrous cycle has been reported by Saini et al. (2021); Islam et al. (2020) in indigenous cows; Oyedipe et al. (1986) in Nigerian zebu cows. However, the magnitude of serum progesterone may vary from breed to breed. Islam et al. (2020) observed a progressive increase in serum progesterone from \u0026lt;1 ng/ml to \u0026ge;27 ng/ml on days 4 - 6 and consequent follicular deviation in Red Chittagong cows.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eProgesterone plays an important role in follicle development, and the functional status of CL and also affect LH secretion (Noseir et al. 2003; McDonald et al.1980). The post-ovulatory rise in progesterone level occurs due to luteinization of follicular cells and the development of the corpus luteum. Developing corpus luteum is the source of high progesterone concentration during luteal phase of the cycle under the stimulation of LH hormone (Islam et al.2020). High progesterone levels during luteal phase are required for the creation of a uterine environment for the successful implantation of the zygote. Mid-cycle high progesterone level exerts its negative feedback action on the hypothalamic hypophyseal axis, thus preventing follicular maturation and ovulation. A decline in serum progesterone levels beyond day 13, recorded in this study, collated with the regression of corpus luteum. The level of estradiol in the Lakhimi cow during the estrous cycle was highest on the day before estrus, on day 0, and maintained a low concentration throughout the cycle, as reported by Islam et al. 2020). Only a peak concentration of LH in the Lakhimi cow on day 1 of the estrous cycle, was maintained at a very low throughout the cycle which is crucial for final oocyte maturation as reported by Dias et al. (2010).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe ovarian follicular dynamics pattern in Lakhimi cows followed two wave patterns mostly with low numbers of follicles (\u0026gt;3mm). The circulating serum progesterone, estradiol, and LH concentrations dynamics are almost similar to other indigenous cows. However, the size of the dominant follicle and pre-ovulatory follicles were smaller than the cross-breed Holstein and can be comparable with the local indigenous breeds like zebu, red Chittagong cows, Bhraman cow, etc. De Lima et al. (2020) have pointed the close relationship between follicular dynamics, progesterone concentrations, pregnancy rates with a high or low antral follicle count in Bos Indicus. Documentation of an ovarian follicular wave phenomenon in this potential Lakhimi cattle breed will provide insight for understanding the folliculogenesis of native cattle estrus cycle, proper heat detection, the timing of artificial insemination, and have profound implications for infertility diagnosis, repeat breeding, and treatment. To explore the optimum reproductive potential and to preserve the germplasm, future works may be initiated to identify the follicular number, and DF size concerning fertility index with its molecular mechanism for this breed.\u0026nbsp;\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eFunding\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eDirectorate of\u0026nbsp;Biotechnology Govt of India\u0026nbsp;under\u0026nbsp;twinning project\u0026nbsp;Programme\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003cstrong\u003eConflicts of Interest\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe declare no conflict of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgement\u003c/strong\u003e\u003cstrong\u003e:\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAuthors are extending thanks to the\u0026nbsp;Directorate of\u0026nbsp;Biotechnology Govt of India for the Financial support, Dean FVSc AAU Assam India for providing all the facilities, Head Department of Veterinary Physiology and Department of Animal Reproduction Gynaecology and obstetrics for providing all the kind help for carrying out the research work\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e The authors declare that all the data and materials used in this study comply with field standards and are available on demand.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors contribution\u003c/strong\u003e:\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAll authors contributed to the study\u0026rsquo;s conception and design. Material preparation, data collection, and analysis were performed by Anupam Datta , Anubha Baruah, Arundhati Bora, D.J. Dutta,J. Goswami,D. Bhuyan, The first draft of the manuscript was written by Sukanta Das, Avishek Paul and Anupam Datta .All authors read and approved the final manuscript.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eHttps:\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e//nbagr.icar.gov.in/en/home/\u003c/span\u003e\u003cspan address=\"http:////nbagr.icar.gov.in/en/home/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAlvarez, P., Spicer, L. J., Chase Jr, C. C., Payton, M. E., Hamilton, T. D., Stewart, R. E., Hammond, A. C., Olson,T. A., Wettemann, R. P. (2000).Ovarian and endocrine characteristics during an estrous cycle in Angus, Brahman, and Senepol cows in a subtropical environment. Journal of Animal Science, 78(5), 1291\u0026ndash;1302\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAdams, G.P., Jaiswal, R., Singh, J. and Malhi, P. (2008) Progress in Understanding Ovarian Follicular Dynamics in Cattle. Theriogenology, 69, 72\u0026ndash;80\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAlves, N. G., Da Costa, E. P., Guimaraes, J. D., Silva, M. R., Zamperlini, B., Costa, F. M. J., Santos, A. D. F., Miranda-Neto, T. (2002). Ovarian activity in Holstein and crossbred Holstein X Zebu cows during two normal estrous cycles. Revista Brasileira-de-zootecnia, 31(2), 627\u0026ndash;634\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAmrozi, A., Kamimura, S., Ando, T., Hamana, K. (2004). Distribution of estrogen receptor alpha in the dominant follicles and corpus luteum at the three stages of estrous cycle in Japanese black cows. The Journal of Veterinary Medical Science, 66,1183\u0026ndash;1188\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBergfeld, E. G. M., Kojima, F. N., Cupp, A. S., Wehrman, M. E., Peters, K. E., GarciaWinder, M., Kinder, J. E. (1994). Ovarian follicular development in prepubertal heifers os influenced by level of dietary energy intake. Biology of Reproduction, 51,1051\u0026ndash;1057\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBhosrekar, M. R. (2006). Buffalo for rural upliftment fertility management of buffaloes, National symposium on Buffalo for Rural upliftment- Physiology and Reproduction. May, 27\u0026ndash;30, Bombay Veterinary College, Mumbai, pp.\u0026nbsp;67\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBoni, R., Roelofsen, M.W.M., Pieterse, M. C., Kogut, J.,Kruip, T. (1997). Follicular dynamics, repeatability and predictability of follicular recruitment in cows undergoing repeated follicular puncture. Theriogenology, 48(2), 277\u0026ndash;289\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBurns, D. S., Jimenez-Krassel, F., Ireland, J. L., Knight, P.G., Ireland, J. J. (2005). Numbers of antral follicles during follicular waves in cattle: evidence for high variation among animals, very high repeatability in individuals, and an inverse association with serum follicle-stimulating hormone concentrations. Biology of Reproduction, 73(1), 54\u0026ndash;62\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDias, F. C., Colazo, M.G., Kastelic, J. P., Mapletoft, R.J., Adams, G.P., Singh, J. (2010) Progesterone concentration, estradiol pretreatment, and dose of gonadotropin-releasing hormone affect gonadotropin-releasing hormonemediated luteinizing hormone release in beef heifers. Domestic Animal Endocrinology, 39,155\u0026ndash;162\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDe Lima, M.A., Morotti, F., Bayeux, B.M., Rezende, R.G., Botigelli, R.C., De Bem, Patr\u0026iacute;cia,T.H.C., Fontes, K., Nogueira, M.F.G., Meirelles, F.V., Baruselli, P.S., Silveira, J.C., Perecin,F., Seneda, M.M. (2020). Ovarian follicular dynamics, progesterone concentrations, pregnancy rates and transcriptional patterns in Bos indicus females with a high or low antral follicle count. Scientifc Reports, 10,19557\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEvans, A.C.O., Currie, W. D., Rawlings, N.C. (2012). Effects of naloxone on circulating gonadotropin concentrations in prepubertal heifers from 2 to 36 weeks of age. Journal of Reproduction and Fertility, 102,463\u0026ndash;470\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFigueiredo, R. A., Barros, C. M., Pinheiro, O. P., Soler, J.M.P. (1997). Ovarian follicular dynamics in Nellore breed (Bos indicus) cattle. Theriogenology, 47(8), 1489\u0026ndash;1505\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFilho, S. A. S., Olivera, M. A. L., Caldaa, J. G. L., Lima, P. F., Donato, I. V. (2001). Ovarian follicular dynamics of five eight Girolando cows. Reproduction in Domestic Animals, 36(3\u0026ndash;4), 207\u0026ndash;210\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFortune, J. E. (1993). Follicular dynamics during the bovine oestrous cycle: a limiting factor in improvement of fertility. Animal Reproduction Science, 33(1\u0026ndash;4),111\u0026ndash;125\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFortune, J. E. (2003). The early stages of follicular development: activation of primordial follicles and growth of preantral follicles. Animal Reproduction Science, 78(3\u0026ndash;4), 135\u0026ndash;163\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGambini, A.L.G., Moreira, M.B.P. Castilho, C., Barros, C.M (1998). Follicular development and synchronization of ovulation in Gir cows. Brazilian Journal of Animal Reproduction, 22 (4), 201\u0026ndash;210\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGaur, M., Purohit, G. N. (2007). Follicular dynamics in Rathi (Bosindicus) cattle. Veterinarski Arhiv, 77(2), 177\u0026ndash;186\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGinther, O.J., Kot, K., Kulick, L.J., Martin, S.,Wiltbank, M.C. (1996). Relationships between FSH and ovarian follicular waves during the last six months of pregnancy in cattle. Journal of Reproduction and Fertility, 108, 271\u0026ndash;279\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKnopf, L., Kastelic, J.P., Schallenberger, E., Ginther, O. J. (1989). Ovarian follicular dynamics in heifers: Test of two wave hypothesis by ultrasonically monitoring individual follicles. Domestic Animal Endocrinology, 6(2),111\u0026ndash;119\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLammoglia, M. A., Short, R. E., Bellows, S. E., Bellows, R. A., MacNeil, M. D., Hafs, H. D. (1998). Induced and synchronized estrus in cattle: Dose titration of estradiol benzoate in peripubertal heifers and postpartum cows after treatment with an intravaginal progesterone-releasing insert and prostaglandin F2α. Journal of Animal Science, 76, 1662\u0026ndash;1670\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLucy, M. C., Savio, J. D., Badinga, R. L., De La Sota, R. L., Thatcher, W. W. (1992). Factors that affect ovarian follicular dynamics in cattle. Journal of Animal Science, 70, 3615\u0026ndash;3626\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMcDonald, L. E. (1980). Veterinary Endocrinology and Reproduction, 3rd Edn. Lea and Febiger, Philadelphia.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOyedipe, E. O., Voh Jr, A. A., Marire, B. N., Pathiraja, N. (1986). Plasma progesterone concentrations during the oestrous cycle and following fertile and non-fertile insemination of zebu heifers. British Veterinary Journal, 142(1), 41\u0026ndash;46\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePinheiro, O. L., Barros, C. M., Figueiredo, R. A., Do Valle, E. R., Encarna\u0026ccedil;\u0026atilde;o, R. O., Padovani, C. R. (1998). Estrous behavior and the estrus-to-ovulation interval in nelore cattle (Bos indicus with natural estrus or estrus induced with prostaglandin F2α or norgestomet and estradiol valerate. Theriogenology, 49(3), 667\u0026ndash;681\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRao, L. V., Pandey, R. S. (1982). Seasonal changes in plasma progesterone concentrations in buffalo cows (Bubalus bubalis). Reproduction, 66(1), 57\u0026ndash;61\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRhodes, F. M., Fitzpatrick, L. A., Entwistle, K. W., De\u0026rsquo;ath, G. (1995). Sequential changes in ovarian follicular dynamics in Bos indicus heifers before and after nutritional anestrus. Journal of Reproduction Fertility, 104(1), 41\u0026ndash;49\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRoche, J. F., Boland, M. P. (1991).Turnover of dominant follicles in cattle of different reproductive states. Theriogenology, 35(1), 81\u0026ndash;90\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSavio, J. D., Thatcher, W. W., Bandinga, R. I., Sota, R. I., Wolfenson, D. (1993). Regulation of dominant follicle turnover during the oestrous cycle in cows. Journal of Reproduction Fertility, 7, 197\u0026ndash;203\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSirois, J., Fortune, J.E. (1988) Ovarian follicular dynamics during the oestrous cycle in heifers monitored by real time ultrasonography. Biology of Reproduction, Madison, 39, 308\u0026ndash;317\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSunderland, S. J., Crowe, M. A., Boland, M. P., Roche, J. F., Ireland, J. J. (1994) Selection, dominance and atresia of follicles during the oestrous cycle of heifers. Journal of Reproduction Fertility, 101, 547\u0026ndash;555\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSaini,G.,Yadav,V.,Kumar,S.,Pandey,A. (2021). Importance of indigenous cattle and peculiarity of their reproductive cycle: A review. The Pharma Innovation Journal,10(11), 156\u0026ndash;159\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTom, J. W., Pierson, R. A., Adams, G. P. (1998). Quantitative echotexture analysis of bovine ovarian follicles. Theriogenology, 50, 339\u0026ndash;346\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eViana, J. H. M., A. de- M. Fereirs; W. F. de S. B., L. S. de A. Camargo (2000). Follicular dynamics in zebu cattle. Pesquira-Agropecuaria-Brasileira, 35(12), 2501\u0026ndash;2509\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMorotti, F. (2015). Is the number of antral follicles an interesting selection criterium for fertility in cattle. Animal Reproduction,12, 479\u0026ndash;486.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMorotti, F. (2017). Antral follicle count in cattle: Advantages, challenges, and controversy. Animal Reproduction, 14, 514\u0026ndash;520\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZangirolamo, A. F., Morotti, F., da Silva, N. C., Sanches, T. K., Seneda, M. M.(2018). Ovarian antral follicle populations and embryo production in cattle. Animal Reproduction,15, 310\u0026ndash;315\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSeneda, M. M. (2019). Antral follicle population in prepubertal and pubertal heifers. Reproduction Fertility Development, 31, 10\u0026ndash;16\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIreland, J. L. (2008). Antral follicle count reliably predicts number of morphologically healthy oocytes and follicles in ovaries of young adult cattle. Biology of Reproduction, 79, 1219\u0026ndash;1225\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIreland, J. J. (2011). Does size matter in females? An overview of the impact of the high variation in the ovarian reserve on ovarian function and fertility, utility of anti-Mullerian hormone as a diagnostic marker for fertility and causes of variation in the ovarian reserve in cattle. Reproduction Fertility Development, 23, 1\u0026ndash;14\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIslam, S., Kabir, Md.A., Miraz, Md.F.H., Tamanna, E.J., Sarker, S.R., Islam, Z., Hossain, S.M.J., Hossain, S. and Deb, G.K. (2020) Investigation of Ovarian Follicular Waves and Major Hormonal Profile in Red Chittagong Cattle. Advances in Bioscience and Biotechnology, 11, 7\u0026ndash;21\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJimenez-Krassel, F., Scheetz, D. M., Neuder, L. M., Pursley, J. R., Ireland, J. J.(2016). A single ultrasound determination of \u0026ge; 25 follicles \u0026ge; 3 mm in diameter in dairy heifers is predictive of a reduced productive herd life. Journal of Dairy Science,100,5019\u0026ndash;5027\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSantos, G. M. G. (2016). High numbers of antral follicles are positively associated with in vitro embryo production but not the conception rate for FTAI in Nelore cattle. Animal Reproduction Science, 165, 17\u0026ndash;21\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSilva-Santos, K. C. (2014). Antral follicle populations and embryo production in vitro and in vivo of Bos indicus-taurus donors from weaning to yearling ages. Reproduction in Domestic Animal, 49, 228\u0026ndash;232\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMoraes, F. L. Z., Morotti, F., Costa, C. B., Lunardelli, P. A., Seneda, M. M. (2019) Relationships between antral follicle count, body condition, and pregnancy rates afer timed-AI in Bos indicus cattle. Theriogenology, 136, 10\u0026ndash;14\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMorotti, F. (2018). Ovarian follicular dynamics and conception rate in Bos indicus cows with diferent antral follicle counts subjected to timed artifcial insemination. Animal Reproduction Science, 188, 170\u0026ndash;177\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMossa, F. (2012). Low numbers of ovarian follicles \u0026ge; 3mm in diameter are associated with low fertility in dairy cows. Journal of Dairy Science, 95, 2355\u0026ndash;2361\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNoseir, W.M. (2003) Ovarian Follicular Activity and Hormonal Profile during Estrous Cycle in Cows: The Development of 2 versus 3 Waves. Reproductive Biology and Endocrinology, 1, 50\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSingh, J., Dominguez, M., Jaiswal, R., Adams, G. P. (2004) A simple ultrasound test to predict the super stimulatory response in cattle.Theriogenology, 62, 227\u0026ndash;243\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVasconcelos, J.L.M., Sartori, R., Oliveira, H.N., Guenther, J.G., Wiltbank, M.C. (2001) Reduction in Size of the Ovulatory Follicle Reduces Subsequent Luteal Size and Pregnancy Rate. Theriogenology, 56, 307\u0026ndash;314\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":true,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Assam Local Cow. Follicular wave. Lakhimi cow. Ovary. Oestrus Cycle","lastPublishedDoi":"10.21203/rs.3.rs-2926683/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-2926683/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eLakhimi is a very promising indigenous dual cattle breed of Assam, India, with their superior draught power capacity, heat tolerance, disease resistance, and adaptability to harsh agro-climatic conditions. The present study was designed to monitor the ovarian follicular dynamics and hormonal profile during the estrus cycle in Lakhimi cows. The study revealed that two follicular wave cycles were predominant (66.7%) in Lakhimi cows with the least duration of ovulatory wave in both two and three-wave cycles. The emergence of wave in the two-wave cycle was 1.16\u0026thinsp;\u0026plusmn;\u0026thinsp;0.30 and 10.83\u0026thinsp;\u0026plusmn;\u0026thinsp;0.47 while in three wave cycle on day 0.83\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16, 7.33\u0026thinsp;\u0026plusmn;\u0026thinsp;0.49, and 12.16\u0026thinsp;\u0026plusmn;\u0026thinsp;0.47 of the cycle. The number of the antral follicular count was more in two waves estrous cycle (4.33\u0026thinsp;\u0026plusmn;\u0026thinsp;0.49 number in the ovulatory wave) compare to three wave cycle with 3.66\u0026thinsp;\u0026plusmn;\u0026thinsp;0.33 number of follicles. The maximum size of the DF two and three follicular waves were 11.51\u0026thinsp;\u0026plusmn;\u0026thinsp;0.54 mm and 12.41\u0026thinsp;\u0026plusmn;\u0026thinsp;0.69 mm respectively. The hormonal dynamics were characterized by peak progesterone concentration (ng/ml) on day 10th day. estradiol on the 20th (the day before estrous) and the day of heat, and LH peak on the 1st day of estrous with subsequent low concentration in Lakhimi Cows. So ovarian follicular waves in Lakhimi cows were characterized by two wave cycles with a low antral follicular count, less diameter of DF, and lower concentration of LH, Progesterone, and estradiol.\u003c/p\u003e","manuscriptTitle":"Insight into ovarian follicular dynamics and hormonal interplay during estrus period in Lakhimi cow of Assam","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2023-06-12 14:48:48","doi":"10.21203/rs.3.rs-2926683/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"dcf6dfea-799c-434b-b667-4ef63e480238","owner":[],"postedDate":"June 12th, 2023","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-01-26T08:12:40+00:00","versionOfRecord":[],"versionCreatedAt":"2023-06-12 14:48:48","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-2926683","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-2926683","identity":"rs-2926683","version":["v1"]},"buildId":"GqpaHPwrfC8PjnIFayRh5","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}