Ruminant Nutrition: Calves and Heifers

Objective was to determine the influence of breed and quantity of milk replacer fed on the performance of dairy calves. Forty-two bull calves (n = 20 Holstein and n = 22 Jersey, 2 ± 1 d old) in a 2 × 2 factorial arrangement were observed through 11 weeks of age. Holstein and Jersey calves on the lower plane of nutrition were fed a 20% protein and 20% fat milk replacer at a rate of 454 g / d. Holstein calves on the higher plane of nutrition were fed a 28% protein and 20% fat milk replacer at a rate of 810 and 1,180 g / d for wk 1 and wk 2 – 6, respectively. Jersey calves on the higher plane of nutrition were fed a 28% protein and 25% fat milk replacer at a rate of 568 and 680 g / d for wk 1 and wk 2 – 6, respectively. At wk 7 all milk intakes were reduced to 50% to stimulate starter consumption. Calves were weaned when consuming 900 g/d of starter. There were breed × plane of nutrition × time interactions (P < 0.01) for milk refusal, starter intake, and total energy intake. Holstein calves fed the lower plane of nutrition had greater starter intakes from wk 4 through wk 8 than Holsteins fed the higher plane of nutrition. Plane of nutrition did not influence starter intake in Jersey calves. Calves fed the higher planes of nutrition had greater total energy intakes before weaning; however, after reducing milk intakes at wk 7 there was no difference within breed. There was an interaction of plane of nutrition and time (P < 0.01) on average daily gain; whereas calves fed the higher planes of nutrition had greater gains from wk 1 to 6, but were not different from the calves fed the lower planes of nutrition from wk 7 to 11. Utilization of energy for body weight gain was greater for calves fed higher planes of nutrition (P < 0.01) and Holsteins (P < 0.02) from wk 1 to 6; however, from wk 7 to 11 the opposite was observed for plane of nutrition (P < 0.05) and breed (P < 0.01). These data indicate under the current higher plane of milk feeding schemes both Holstein and Jersey calves performed well; however, the amount of milk replacer fed to Jersey calves may be able to be increased during the pre-weaning period.