Benefits of tributyrin on growth performance, gastrointestinal tract development, ruminal bacteria and volatile fatty acid formation of weaned Small-Tailed Han lambs.

This study aimed to determine the effects of tributyrin on growth performance, gastrointestinal tract development, ruminal bacteria and volatile fatty acid (VFA) formation. Thirty healthy weaned Small-Tailed Han female lambs at 3 months old with BW 27.5 ± 4.1 kg (mean ± SD) were randomly assigned to five groups of six lambs each, and each group received tributyrin at 0, 0.5, 1.0, 2.0 and 4.0 g/kg in feed. Weights were measured before the start and end of the study. After 15 d adaptation, DMI, feed, faeces and urine were recorded every week. Lambs were sacrificed at d 75. Compared to lambs fed no tributyrin, lambs fed 4.0 g/kg tributyrin had higher average daily BW gain ( = 0.04) and DMI ( < 0.01). Tributyrin reduced nitrogen ( < 0.01), Ca ( < 0.01) and P ( < 0.01) losses derived from faeces and urine. The mostly important, tributyrin increased dorsal sac thickness ( < 0.01), papillae length ( = 0.04) and width ( < 0.01), ventral sac papillae length ( < 0.01) and width ( < 0.01), caudodorsal blind sac thickness ( = 0.02), papillae length ( < 0.01) and width ( < 0.01). Furthermore, tributyrin increased thicknesses of both the duodenum ( < 0.01) and ileum ( = 0.01), and villus heights of the duodenum ( = 0.01), ileum ( < 0.01), jejunum ( < 0.01) and caecum ( = 0.02), but tributyrin decreased duodenal ( < 0.01) and caecal crypt depths ( < 0.01). Tributyrin reduced rumen pH ( < 0.01) while promoting total VFA concentration ( < 0.01). Tributyrin improved the structure of rumen bacteria by enhancing ( = 0.04), ( < 0.01), ( = 0.04), ( = 0.04), ( = 0.02) and ( = 0.03). In conclusion, tributyrin could stimulate gastrointestinal tract development by enhancing colonization of rumen VFA-producing bacteria, and dietary supplementation of tributyrin at 4.0 g/kg of DM was recommended for the weaned lambs.