Effects of hydrolyzed cottonseed protein added to poor or good quality colostrum and milk on performance, health, and metabolism in Holstein dairy calves

Abstract The objective of this experiment was to investigate the effects of supplementing colostrum and milk with a cottonseed protein hydrolysate (CSPH) as a peptide source on the performance, antioxidant status, blood hormones, and metabolites in calves. Fifty-six newborn Holstein calves were randomly assigned to one of four dietary treatments in a 2 × 2 factorial arrangement with different colostrum quality (good or poor) and CSPH addition to colostrum and milk (0 and 2% fresh-matter basis) fed to calves from birth to 14 days of age. All the calves received equal amounts of colostrum and pasteurized waste milk, were weaned at d 56 of the experiment, and remained in the study until d 70 of the trial. The interaction between CSPH addition and colostrum quality was significant for starter intake and CSPH supplementation increased starter intake only in calves receiving the poor-quality (P =  0.03), but not in those received good-quality colostrum. Body weight and skeletal growth parameters were not affected by colostrum quality or CSPH supplementation. The calves receiving good-quality colostrum recorded lower ear disposition scores (P = 0.03) while those received the CSPH exhibited lower (P