Metabolic and endocrine traits of neonatal calves are influenced by feeding colostrum for different durations or only milk replacer.

Bovine colostrum contains various essential nutrients, antibodies, hormones and growth factors that are important for nutrient supply, host defense, growth and for general neonatal adaptation. We have studied effects of colostrum fed for different durations on selected metabolic and endocrine traits in the first week of life in calves. Calves were fed colostrum twice daily for 3 d (group C6) or colostrum only as their first meal (group C1), followed by milk replacer up to d 7, or they were only fed milk replacer but no colostrum (group M). Plasma concentrations of immunoglobuline G and activities of enzymes (gamma-glutamyltransferase, aspartate-aminotransferase, lactate-dehydrogenase, glutamate-dehydrogenase) increased in groups C6 and C1 after first feeding, but not in group M. Postprandial plasma glucose concentrations on d 2 increased significantly more in groups C6 and C1 than in group M. Plasma triglycerides on d 2 and plasma phospholipid and cholesterol concentrations on d 7 were significantly higher in group C6 than in groups C1 and M. Plasma insulin concentrations on d 2 tended (P = 0.07) to increase more postprandially in group C6 than in group M and postprandial plasma glucagon concentrations on d 1 increased more in groups C6 and C1 than in group M and remained elevated on d 2 only in group C6. Plasma cortisol concentrations decreased postprandially in all three groups and were highest on d 2 and d 7 in group M. Plasma triiodthyronine and thyroxine concentrations decreased in the first week of life in all calves, whereas plasma prolactin concentrations were greatest on d 7 in group C6. In conclusion, various metabolic and endocrine traits were influenced by whether colostrum was fed and the duration of colostrum feeding.