Use of a Visual Scoring System to Assess External Udder Conformation and Its Relationship to Colostrum Quality and Lamb Growth Rates

In sheep raised for meat production, the relationship between external udder conformation, colostrum quality, and lamb growth rates has not received much attention. We hypothesize that ewes with a more desirable udder conformation at lambing have greater colostrum quality and increased growth rates in lambs. Fifty Suffolk ewes were used in this study. Within 6-8 hours of parturition, colostrum samples from both halves of the udder were collected and a visual scoring of the udder was conducted. Colostrum quality was measured for total protein using both optical and Brix refractometers. On day 2, day 45, and day 60 after parturition, lamb weights were recorded, and udder conformation measurements were repeated. A visual scoring system evaluating udder floor (scale 1-4), udder depth (scale 1-9), teat placement (scale 1-9), teat lesions (present or absent), and the presence of wool (present or absent) was used to assess external udder conformation. Normal udder parameters include udder depth scores of 5 or 6, udder floor score of 1 or 2, teat placement scores 4, 5, and 6, and the absence of teat lesions and wool. All ewes not meeting normal parameters were considered to have an abnormal udder. The data was analyzed using the GLM procedure. Mean total colostrum total protein was greater (p = 0.03) in ewes displaying ‘normal’ udder conformation compared with those with ‘abnormal’ (14.82±0.5 and 13.31±0.3mg/dl). Mean Brix values were also greater (p = 0.03) for ewes with a ‘normal’ udder compared to an abnormal udder confirmation, respectively (21.70±0.8 and 19.54±0.5). On day 2 after parturition, mean lamb body weight was not different between ewes with ‘normal’ and abnormal udder (5.38±0.26 vs 5.46±0.15). No difference (p > 0.05) in lamb weights were detected between ewes with normal and abnormal udder conformations on day 45 and 60 after parturition. This data provides evidence of increased colostrum total protein values and increased Brix values present in ewes with ‘normal’ udder conformation and no difference in lamb weights between udder conformations.