Performance of Holstein calves receiving increased nutrient intake through the addition of skim milk or milk replacer powder to the whole milk

The purpose of this research was to describe the performance of Holstein calves before and after weaning when total solids in their daily milk were increased with skim milk or milk replacer powder. Forty-five female Holstein calves (body weight = 39.5 +/- 1.61 kg) were assigned in random to 1 of 3 treatments: 1) whole milk (WM) with total solids of 123 +/- 4.1 g/kg, 2) whole milk + skim milk powder (WM + SM) with total solids of 181 +/- 6.2 g/kg, and 3) whole milk + milk replacer powder (WM + MR) with total solids of 184 +/- 9.7 g/kg. Calves received 6 l/day of milk from days 2-14, 7 l/day from days 15-35, 6 l/day from days 36-42, 5 l/day from days 43-49, and then 2 l/day from days 50 until weaning (d 56). Calves remained in the study until day 90. Calves exhibited no difference in their pre- and post-weaning starter consumption. Although pre-weaning feed conversion efficiency was slightly different among calves, postweaned calves receiving WM were more efficient in converting feed nutrients to body weight gain. Evolution of body frame development was slightly different among calves. However, WM + SM-fed calves had greater body length at weaning. Pre-weaning weight gain and body weight at weaning were greater when calves consumed high-solids milk based on SM or MR. Feeding WM + SM increased the number of days with diarrhea, which resulted in the highest proportion of calves in this group to receive antibiotics treatment. Amount of electrolytes administered per calf as well as days with antibiotic therapy were generally lesser in WM-fed calves. Slight treatment differences were noted in post-weaning total-tract digestion of DM, CP and OM in calf starter. However, fat digestibility was greatest in calves consuming WM + SM. Overall, our findings indicate that a high-solids milk feeding strategy based on SM or MR improved calf growth rate in the preweaning phase while having no effect on starter consumption. However, diarrhea incidence increased when calf nutrient intake was increased through SM.