Animal Industry Report

Extension Number

ASL R2298



Summary and Implications

Effects of neonatal growth rate on plasma concentrations of fat-soluble vitamins, zinc, and copper in preruminant calves were evaluated. Calves were assigned to dietary treatments designed to achieve three targeted rates of gain [No-Growth (NG) = 0.0 kg/d, Low-Growth (LG) = 0.55 kg/d, or High-Growth (HG) = 1.2 kg/d] over a 7 wk period. MR intakes needed to achieve specified growthrates were estimated using the NRC Nutrient Requirements of Dairy Cattle calf model computer program. Calves were fed a 30% CP, 20% fat, MR reconstituted to 14% DM. Because vitamin levels in the MR were based on DM intake of HG calves, NG and LG calves were supplemented with additional vitamins once weekly to compensate for reduced MR consumption. Growth rates for NG (0.11 kg/d), LG (0.58 kg/d), and HG (1.16 kg/d) calves differed throughout the study. Although vitamins A and D, and Zn concentrations were unaffected by growth rate, their concentrations increased and Zn/Cu concentrations decreased with time. Throughout the study their concentrations remained within normal ranges for the preruminant calf. Vitamin E and copper were affected by growth rate. At wk 7, HG calves had lower vitamin E concentrations than LG and NG calves. Copper concentrations were greater for HG calves than LG and NG calves from wk 4 to wk 7. Copper and vitE concentrations, however, remained within ranges considered normal for preruminant calves. These results suggest that growth rate during the neonatal period influences vitE and Cu availability

Copyright Holder

Iowa State University