Effect of Probiotic Supplementation to Complete Rations on the Nutrient Digestibility and Rumen Environment in Sheep

A complete ration with 60:40 roughage to concentrate ratio (CR-1) supplemented with Lactobacillus acidophilus, 1 g (CR-2), Saccharomyces cerevisiae (Yea-sacc¹⁰²⁶), 10g (CR-3) or L. acidophilus, 0.5g + Yea-sacc¹⁰²⁶, Sg (CR-4) was fed to 16 Nellore brown rams (26.06 kg±0.6 b.wt) divided into 4 groups of 4 animals each In a completely randomised experiment. The CP digestibility in CR-1 (60.7) was significantly lower (P<0.01) than those in CR-2 (72.9), CR-3 (78.6) or CR-4 (73.5). Improved fermentation efficiency due to Yea-sacc¹⁰²⁶ supplementation resulted in higher (P<0.01) CF and cell wall constituents digestibility on CR-3 than on CR-1. Per cent DCP, TDN besides ME (Mcal/kg) contents of the complete rations 1 to 4 were 9.3, 58.4, 2.1; 10.8, 62.4, 2.3; 10.9, 69.7, 2.5 and 10.2, 64.0, 2.3, respectively and the variations among rations were significant. Retention of N was significantly lower (P<0.05) on CR-1 compared to CR-2, 3 or 4. All the rams were in positive balances for Ca and P. No difference existed for ruminal pH and NH₃-N. However, significantly higher TVFA production (m.mole/1) was observed in CR-3 compared to CR-1, 2 or 4. The total ruminal bacterial count on CR-4 (64.5 x 10⁹) was significantly higher (P<0.01) than CR-1 (36 x 10⁹). The study inferred that probiotic supplementation to complete rations improved rumen bacterial count, TVFA production and nutrient digestibility in sheep.