Effect of propionate, monensin, and saccharomyces cerevisiae or their combination on production and rumen fermentation of holstein steers

This study aimed to evaluate the effects of calcium propionate (PrCa), PrCa + monensin sodium (PrCa + Mon), and PrCa + Saccharomyces cerevisiae (PrCa + Sc) on the productive performance of Holstein steers. Twenty-four Holstein steers (270.0 ± 25.85 kg) were distributed individually into four treatments of six replicates. The treatments were control (no additives), PrCa (10 g/kg), PrCa + Mon (10 g/kg + 30 mg/kg), and PrCa + Sc (10 g/kg + 12.8 × 109 cfu). The steers were fed for 43 days, and afterwards, nutrient intake and digestibility as well as volatile fatty acids were determined, while the weight gained, feed efficiency, and CH4 production were calculated. Diet of PrCa + Sc had the highest (P < 0.0001) acid detergent fiber intake and propionate acid as well as the nutrient digestibility, with lowest (P < 0.0001) rumen acetic acid, methane, and protozoa concentration versus other diets. In conclusion, dietary inclusion of PrCa + Sc (10 g/kg + 12.8 × 109 cfu) improved nutrient digestibility, rumen fermentation, and reduced methane emission, thereby enhancing the possibility of ecofriendly ruminant farming. Graphical Abstract: [Figure not available: see fulltext.].