Evaluation of a high or low level of milk replacer, with or without varied intake, on neonatal Holstein calf performance and health

Neonatal Holstein bull calves (n = 30; age ~ 1 wk; average BW = 39 ± 5.4 kg) were allocated randomly in a 2 × 2 factorial arrangement to evaluate a high or low level of 28% CP, 18% fat milk replacer (MR), with or without varied intake, on calf performance and health. Treatment factors included (1) level (high = 1.13 kg/d or low = 0.45 kg/d) and (2) daily intake (constant or varied). Calves were purchased in 2 blocks and followed for 35 d (block 1) and 42 d (block 2). Intake data and fecal scores were recorded daily; BW data and blood samples were collected weekly. Feeding a high level of milk replacer improved ADG (0.962 vs. 0.858 kg/d), reduced calf starter DMI (0.392 vs. 0.929 kg/d), increased BUN levels (11.62 vs. 9.77 mg/dL; P < 0.05), and tended to improve final BW (80.0 vs. 75.6 kg; P = 0.09). Milk replacer feeding level differed by period for ADG, calf starter DMI, total DMI, and G:F (P < 0.05). Average daily fecal scores and percentage of abnormal-fecal-score days were greater for calves consuming the high compared with the low level of MR (P < 0.001). Providing an inconsistent daily amount of MR had no effect on calf performance or health outcomes. There was no interaction between treatment factors, level and daily intake of MR. These data demonstrate feeding a high level of MR to Holstein bull calves improves preweaning performance but may promote digestive upsets as measured by fecal scores.