Abstract
OBJECTIVE: Post-ruminal supplementation of glucose may contribute to subsequent milk production and health. The objective of this study was to evaluate the effects of bypass sugar (BpS) supplementation to dairy cows during the transition period on milk production and metabolic status after calving. METHODS: Fifteen Holstein cows were randomly assigned into three groups considering parity and previous milk production. The three groups corresponded to the following three treatments: a BpS group supplemented with BpS, a Gly group supplemented with dietary glycerol, and a control group with no supplementation in the basal diet from 21 days pre-partum to 5 days post-partum. Cows were sampled from 21 days pre-partum to 28 days post-partum, and milk yield and blood and health statuses were determined. RESULTS: Milk yield was higher in the BpS group than that in the other groups. The rumen fill score was highest in the BpS group from the dry period to post-partum compared with that in the other groups. Post-partum blood glucose concentrations were higher in the BpS group than in the control group. The prevalence of hyperketonemia and blood concentrations of non-esterified fatty acids, β-hydroxylbutyrate, glucagon-like peptide-2 (GLP-2) and haptoglobin were not different among the groups. In the BpS group, blood aspartate aminotransferase concentration was lower than that in the Gly group. γ-glutamyl transpeptidase was lower than that in the control group. CONCLUSION: From these results, feeding BpS and Gly did not affect GLP-2 secretion and alleviate inflammation after calving, but BpS increased milk production and improved liver function.