EFFECTS OF TRIBUTYRIN SUPPLEMENTATION IN MILK REPLACER ON PERFORMANCE AND GUT DEVELOPMENT OF HOLSTEIN CALVES

Sodium butyrate (SB) is often used as an additive for milk replacers (MR) to improve calf performance. Tributyrin (TRB) is a triglyceride containing equivalent amount of butyrate than SB but in a more stable form. The aim of this study was to evaluate the effects of supplementing a MR with TRB on performance and development of the gastro-intestinal tract (GIT) of suckling calves. Thirty-six Holstein calves (46 ± 5.9 kg BW and 12 ± 3.0 d age) were fed 4 L/d of MR at 12.5% DM dilution 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 TRB per kg of DM (TRB). Five calves per group were feed-restricted at 200 g/d of starter and killed on d 42 of study to measure rumen VFA, pH and GIT weights. Starter and MR intakes were recorded daily on an individual basis and calves were weighed every 14 d. Data for VFA, pH and GIT weights were analyzed using ANOVA and performance parameters were analyzed using ANOVA with time as a repeated measure. Milk replacer intake was greater (P < 0.01) in CTR than in TRB calves (591.7 vs. 585.4 ± 39.02 g of DM/d; respectively). The CTR calves tended (P = 0.06) to have a greater starter feed intake than TRB calves, and total DMI was greater (P < 0.01) in CTR than in TRB calves (358.2 vs. 260.8 ± 1.15 g of DM/d; respectively). Moreover, BW and ADG were greater (P < 0.01) for CTR calves (68.2 ± 0.94 kg and 0.53 ± 0.024 kg/d, respectively) compared with TRB (63.8 ± 0.94kg and 0.42 ± 0.024kg/d; respectively). Gain to feed ratio was also greater (P < 0.05) for CTR calves compared with TRB (0.57 vs. 0.48 ± 0.026; respectively). Rumen pH, VFA profile, and GIT weights were not affected by treatments. Nevertheless, CTR calves tended (P = 0.07) to have a heavier abomasum than TRB calves, whereas TRB calves tended (P = 0.08) to have a heavier duodenum than CTR calves. In conclusion, these results provide no evidence that butyrate addition to MR in the form of TRB at 3 g/kg of DM has positive effects on performance or GIT development of pre-weaned calves. tech.service.fad@lucta.com