Effects of hormone or mineral-vitamin enriched colostrum on performance and weaning age of Holstein calves

The primary objective was to determine the effects of hormone and mineral-vitamin enriched colostrum and milk on preweaning calf performance and weaning age. At day of birth, forty Holstein dairy calves were randomly assigned to 4 treatments of supplements in milk and colostrum for the first 5 days of age. Treatments included colostrum and milk supplements of either (1) control (CTR; no additives), (2) hormone (HRM; consisting of growth hormone, insulin-like growth factors I and II, prolactin, glucagon and insulin), (3) mineral-vitamin (VIT; consisting of selenium, zinc, and vitamins A, D, and E), (4) hormone plus mineral-vitamin (HRVI; consisting of growth hormone, insulin-like growth factors I and II, prolactin, glucagon, insulin, selenium, zinc, and vitamins A, D, and E). Calves received colostrum at 10% of body weight (BW) for 3 d and whole milk from d 4 until weaning. The weaning criterion was defined as the calf age at a daily intake of ≥1000 g of calf starter for 3 consecutive days. Treatments had no effects (P>0.10) on dry matter intake, average daily gain, and feed conversion ratio. There was a trend (P=0.09) for decreased weaning age (6±0.21; mean±STD days) in calves fed HRM, VIT, and HRVI compared to CTR-calves. Calves fed HRM and VIT consumed less milk than CTR-calves (P=0.05) to meet the weaning criterion owing to promoted starter intake. However, treatments did not differ (P>0.10) in BW gain and weaning BW. The albumin to globulin ratios were not affected by treatments (P>0.10). Results show that using hormone or mineral-vitamin enriched colostrum and milk during the first 5 days after birth may stimulate early calf starter intake and thereby reduce weaning age.