Effects of yeast, tannin, and amylolytic enzyme combinations in high-concentrate diets on feed intake, nutrient digestibility, and serum metabolites in Lambs.

The purpose of this study was to evaluate the combined effects of yeast, tannin, and amylolytic enzymes on intake, digestibility, and biochemical parameters of lambs fed a high-concentrate diet. A total of five lambs were used in a 5 × 5 Latin square design. Diets consisted of 75% concentrate and 25% roughage. The treatments were: control (without additive), TE (tannin and enzyme), EY (enzyme and yeast), TY (tannin and yeast), and TYE (tannin, yeast, and enzyme). Digestibility trials were conducted to determine nutrient intake and digestibility, as well as urinary, fecal, and serum parameters. Analyses of variance were applied, and means were compared using Tukey's test at a 5% significance level. No differences were observed in nutrient intake or urinary and fecal parameters with the inclusion of feed additives (P > 0.05). However, dry matter digestibility increased with additive inclusion (775 vs. 749 g kg- 1 day- 1, P = 0.04). Crude protein digestibility decreased (886 vs. 912 g kg- 1 day- 1, P < 0.0096) with the combination of tannin and yeast. For metabolites, serum concentrations of gamma-glutamyl transferase (28.5 vs. 25 U/L, P = 0.01) increased, whereas alkaline phosphatase (272 vs. 331 U/L, P = 0.02) decreased with the use of dietary additive. The results suggest that the inclusion of yeast, tannin, and amylolytic enzymes in high-concentrate diets for lambs may contribute to increased dry matter digestibility and changes in selected hepatic parameters, without compromising feed intake or animal health.