Impacts of feeding milk replacer supplemented with increasing concentrations of choline on feed intake, growth, and scouring incidence for 7 weeks preweaning and 1 week postweaning.

The objective of this study was to evaluate the effect of increasing choline supplementation on the intake of milk replacer (MR) and calf starter (CS), growth performance, and fecal scores of calves over 8 wk. One hundred calves from commercial herds were transported to the University of Minnesota Southern Research and Outreach Center (SROC) calf facility randomized to one of 4 treatments differing in choline supplementation within MR including: 0 (C0; n = 24), 700 (C700; n = 26), 1,400 (C1400; n = 25), and 2,100 mg/kg choline (C2100; n = 25). Milk replacer contained a basal concentration of 1,650 mg/kg MR resulting in total choline concentrations in the MR of 1,650 mg/kg for C0, 2,350 mg/kg for C700, 3,050 mg/kg for C1400, and 3,750 mg/kg for C2100. Calves were weaned at 49 d, and the trial ended at 56 d. Body weight was measured at d 0, 14, 28, 42, 49, and 56. Fecal scores were measured weekly. Feed intake was measured daily and calculated every 2 wk. All feeding, BW measurements, and fecal scoring were conducted by the research staff at the University of Minnesota SROC. Growth, feed intake, and gain to feed ratio were analyzed using a linear mixed effects model with choline concentration as a fixed effect and source herd and room as random effects. Initial BW was included as a covariate for average daily gain. Fecal scores were analyzed as a chi-squared test of significance. Feeding 700 mg/kg supplemental choline increased MR intake throughout the preweaning period and increased ADG in both the preweaning and postweaning periods compared with the other treatments. No differences were observed for fecal scores across treatments. Results suggest that calf performance can be improved with MR containing 2,350 mg/kg choline, contrasting with current NASEM (2021) requirements of 1,000 mg/kg.