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.

Influence of phytase enzyme on ruminal biogas production and fermentative digestion towards reducing environmental contamination.

Environmental impact of livestock production has received a considerable public scrutiny because of the adverse effects of nutrient run-offs, primarily N and P, from agricultural land harboring intensive energy livestock operations. Hence, this study was designed to determine the efficacy of dietary phytase supplementation on fermentation of a sorghum grain-based total mixed ration (TMR) using a ruminal in vitro digestion approach. Phytase was supplemented at three doses: 0 (control), 540 (P540), and 720 (P720) g/t dry matter, equivalent to 0, 2.7 × 106, and 3.6 × 106 CFU/t DM, respectively. Compared to P720 and the control, gas production was higher for P540 after 12 h (P = 0.02) and 24 h (P = 0.03) of fermentation suggesting a higher microbial activity in response to phytase supplementation at lower phytase levels. Correspondingly, dry matter degradability was found to have improved in P540 and P720 compared to the control by 13 and 11% after 24 h of incubation (P = 0.05). For ammonia nitrogen (NH3-N), a tendency towards lower values was only observed for P540 at 24 h of fermentation (P = 0.07), while minimal treatment effects were observed at other fermentation times. The concentrations of total volatile fatty acids (VFA) were higher (P < 0.05) after 48 h of fermentation for P540 and P720 compared to the control (P = 0.03) by 10% and 14%, respectively. Ruminal acetate tended towards higher values in the presence of phytase after 12 h of fermentation (P = 0.10), but towards lower values after 24 h of fermentation (P = 0.02), irrespective of the phytase dose applied. A trend towards lower ruminal propionate levels was observed in the presence of phytase after 6 h (P = 0.10) and 12 h (P = 0.06) of fermentation, while no effects were found at other fermentation times. In conclusion, phytase supplementation has the potential to improve metabolic energy activity of rumen microorganisms and the use of feed constituents. Thus, phytase supplementation could help to reduce environmental contamination in areas of ruminant production.

Effect of exogenous xylanase on rumen in vitro gas production and degradability of wheat straw.

The objective of this study was to determine effects of xylanase on in vitro gas production (GP) and in sacco degradability of wheat straw. Rumen fluid was obtained from three Mongolian native goats fitted with permanent rumen cannulas. The trial consisted of five doses (0, 0.5, 1.0, 1.5, 2.0 µL/g of substrate) of a commercial xylanase (Dyadic® xylanase PLUS, Dyadic International, Inc., Jupiter, FL, USA). For the in sacco degradability, different levels of xylanase enzyme were added directly onto 2 g of wheat straw in nylon bags and incubated in the rumen for 3, 6, 12, 24 and 48 h to estimate degradability of wheat straw. Total GP increased (P < 0.001) at all times of incubation at intermediate levels of xylanase. Methane production had a similar pattern at 3 and 12 h of incubation; increased linearly at 24 h of incubation, and was unaffected at 6 and 48 h of incubation. Rumen NH3 -N concentration increased linearly at 3 h and the highest values were observed with intermediate enzyme levels. All ruminal volatile fatty acids increased linearly with intermediate levels of the fibrolytic enzyme. The in sacco rate of dry matter degradation decreased linearly (P = 0.020) with increasing enzymes. Intermediate levels of xylanase improved rumen kinetic fermentation and degradability. The outcome of this research indicated that the application of xylanase enzyme could improve in vitro GP fermentation of wheat straw.