Saccharomyces cerevisiae does not work synergistically with exogenous enzymes to enhance feed utilization, ruminal fermentation and lactational performance of Nubian goats

The present study assessed the effect of in-feed doses of an exogenous enzymes preparation and/or Saccharomyces cerevisiae on production performance, nutrient utilization, ruminal and blood serum measurements in goats. Sixteen lactating Nubian does (35.1 ± 0.8 kg) were utilized in a quadruplicated 4 × 4 Latin square design over a period of 88 days. Enzymes and/or yeast were included in a basal diet (control treatment) at doses of 4 g exogenous enzymes (EZ treatment), 4 g yeast (SC treatment), or 8 g of their mixture at 1:1 w/w (EZSC treatment). The EZ, SC, and EZSC treatments had greater (P < 0.01) feed intake, milk yield, energy corrected milk, milk component yields, and feed (milk) efficiency. In addition, the EZ, SC, and EZSC treatments had greater (P < 0.01) concentrations of milk total solids, solids-not-fat, fat, and lactose compared with the control treatment. Greater (P < 0.05) nutrient digestibility and diet's total digestible nutrients, digestible crude protein, digestible energy, metabolizable energy, and net energy for lactation were observed with feeding EZ, SC, and EZSC treatments. In addition, greater (P < 0.001) ruminal pH, and concentrations of total and individual volatile fatty acids were observed with feeding EZ, SC, and EZSC diets. The SC and EZSC treatments decreased (P < 0.05) ruminal ammonia-N compared with EZ and control treatments. The EZ, SC, and EZSC treatments had greater (P < 0.001) concentrations of blood total proteins, albumin, globulin, and glucose. As a result, it is concluded that in-feed dose of exogenous enzymes or yeast at 4 g/doe/d will enhance feed intake and digestibility, ruminal fermentation, and milk yield and composition in lactating Nubian does. Mixing the exogenous enzymes with the yeast did not show any synergistic effect.