Effects of plane of milk-replacer nutrition on the health, behavior, and performance of high-risk Holstein bull calves from a commercial calf ranch

OBJECTIVE: This research study aimed to determine whether preweaning plane of milk-replacer nutrition influences health, standing and oral behaviors, and performance of high-risk calves. MATERIALS AND METHODS: Thirty-six Holstein bull calves (1 d of age) from a commercial calf ranch were assigned to either a high plane of milk-replacer nutrition (HPN; n = 18; 20 and 28% DM lipid and protein, respectively, Cow’s Match, Land O’Lakes Animal Milk Protein Co., Shoreview, MN) or a low plane of milk-replacer nutrition (LPN; n = 18; 20% DM lipid and protein, Herd Maker, Land O’Lakes Animal Milk Protein Co.) through weaning. Total serum protein concentrations confirmed that 72 and 76% of calves had failure of passive transfer (<5.2 g/dL) in HPN and LPN, respectively. All calves were bottle fed twice daily. The LPN were fed 455 g of DM/d of milk replacer (MR) until weaning, and the HPN calves were fed 830 g of DM/d of milk replacer during the first 10 d and 1,080 g from 11 d until weaning. Calf starter and water were offered ad libitum. Calves were step-down weaned beginning at 51 d and completely weaned after 58 d when consuming 1 kg of calf starter (as-fed basis). Data are reported as HPN versus LPN throughout, respectively. RESULTS AND DISCUSSION: Risk for bloat and scouring were greater for calves fed the HPN, but there was no difference in antibiotic treatment or mortality. The HPN calves had greater performance over the preweaning period including final BW, ADG, and feed:gain (total kg of milk replacer + calf starter, kg of DM/kg of BW gain), but weaning was more stressful for HPN calves. IMPLICATIONS AND APPLICATIONS: In conclusion, the high-risk calves fed a HPN had increased preweaning ADG, but there was also an increased incidence of scours. There may be differences in the health status of calves that may affect the ability to consume and use high MR levels. When feeding high-risk calves there may be a need for alternate strategies when determining the quality and quantity of MR being fed when compared with low-risk calves. Differences in gut integrity may influence the ability of high-risk calves to handle high levels of MR early in life. Potential issues with high-risk calves being fed a HPN might be reduced with increased feeding times per day, a gradual step-up method, or other nutritional strategies that improve gastrointestinal development and function.