Effects of European Propolis administration on the growth performance, health status, selected blood biochemical and immunological variables of pre-weaning calves

Abstract The present study aimed to investigate the effects of oral European Propolis supplementation on health status, growth performance, hematological, and serum biochemical variables of neonatal dairy calves. Twenty-four neonatal dairy calves were enrolled in this study from 48 hours after birth until seven days old. A complete clinical examination was performed daily during the study, by the same person. Blood sampling, body measurements, and lung ultrasonography were conducted on days 0,7,14 and 28. The concentrations of albumin, total protein, total immunoglobulin, triglyceride, total cholesterol, urea, creatinine, inorganic phosphate, and activities of aspartate aminotransferase, alanine aminotransferase, and gamma-glutamyl transferase were measured. PEE supplementation had no significant effect on body weight, daily weight gain, length, and height (P > 0.05). Pulmonary examination scores by ultrasonography for subclinical pneumonia in this study showed a significant difference at different times of examination. However, no significant difference between treatment and control groups. Days with navel ill infection were significantly lower in the propolis treatment group in comparison with control (P value = 0.016). There was not any significant difference concerning days in fever and diarrhea between trial groups (P value = 0.44 and 0.15, respectively). There was not a significant difference in hematological and biochemical variables between trial groups. Our results suggest that European Propolis had no positive effects on growth performance, hematological, and biochemical blood variables. In conclusion, supplementation of the Propolis may be beneficial for better navel ill diseases control in new- born dairy calves. Even though, further studies are needed to clarify propolis effects.