EFFECTS OF SUPPLEMENTING THE MILK REPLACER WITH TRIBUTYRIN ON THE METABOLISM OF HOLSTEIN CALVES

Butyrate in the form of sodium butyrate (SB) is often used as an additive for milk replacers (MR) to improve calf and piglet performance. Tributyrin (TRB) is a triglyceride containing equivalent amounts of butyrate than SB but in a more stable form. Thirty-six Holstein calves (45.7±5.9 kg of BW and 11.9±3.0 d of age) were fed 4 L/d of MR and water and starter feed ad libitum. Calves were randomly distributed in 2 groups. Milk replacer was either unsupplemented (CTR) or supplemented with 3 g of tributyrin per kg of DM (TRB). Five calves per group were restricted at 200 g/d of starter and these calves were subjected to glucose tolerance tests (GTT) to assess resistance on days 0 and 42 of study. Calves were blood-sampled every 14 d for glucose, insulin, GLP-1 and BHBA before and 60 min after the morning MR offer. Calves in the CTR group showed better performance parameters. No differences were found in plasma GLP-1, BHBA, insulin, and glucose between treatments. However, evolution of plasma BHBA along time tended to differ (P<0.08) because on day 14, plasma BHBA concentration before and after MR feeding was similar for TRB calves while CTR calves tended (P=0.06) to have a lesser concentration after MR. Evolution of plasma glucose and insulin across time also differed (P<0.001 and P<0.001, respectively) between treatments. Plasma glucose after morning MR take increased later (P<0.05) in time in TRB than in CTR calves; but CTR calves had greater (P<0.05) insulin levels on day 14 than 28. Results from the GTT showed that glucose peak and GCR on day 42 were greater (P<0.05) for TRB than for C calves (3.5 vs 5.8±0.69 mmol/L and 4.6 vs 17.3±3.09 mmol/Lxmin; respectively) which indicates a different insulin secretion pattern between treatments. In conclusion, these results demonstrate that butyrate supplementation in the form of tributyrin at 3 g/kg of MR modulates glucose and insulin hemodynamic but does not alter BHBA and GLP-1 plasma concentration nor increases performance. tech.service.fad@lucta.com