Abstract #T260

# T260
Effect of a Saccharomyces cerevisiae-based direct-fed microbial product and an enzyme extract from Aspergillus oryzae and Aspergillus niger on productivity and enteric gas emission in lactating dairy cows.
J. Oh*1, M. Harper1, A. Melgar1, D. P. Compart2, A. Hristov1, 1The Pennsylvania State University, University Park, PA, 2PMI Nutritional Additive, Arden Hills, MN.

Dietary supplementation of live yeast and fungal enzymes may have beneficial effects on productivity and rumen fermentation in ruminant animals. The objective of this experiment was to investigate the effects of a Saccharomyces cerevisiae-based direct-fed microbial product (DFM) and an enzyme extract from Aspergillus oryzae and Aspergillus niger (ENZ) on feed intake, milk production and composition, and enteric gas emission in lactating dairy cows. Eighteen Holstein cows (115 ± 42.0 d in milk; 609 ± 77.9 kg body weight) were used in a 3 × 3 Latin square design experiment with 3, 28-d periods. Treatments were: (1) control (no additive), (2) 28 g/cow/d DFM, and (3) 10 g/cow/d ENZ. Treatments were top-dressed at the time of feeding in the morning. The basal diet consisted of (DM basis): 44.5% corn silage, 10.5% alfalfa haylage, 5.0% grass hay, and 40% concentrates and contained 16.5% CP and 32.0% NDF. Feed intake and milk production were monitored daily and gas emission was measured during the last week of each experimental period using the GreenFeed System. Dry matter intake was not affected (P = 0.53) by treatments (average 25.3 kg/d; SEM = 0.97). Compared with control, DFM increased (P = 0.03) milk yield (39.7 vs. 41.9 kg/d, respectively). Feed efficiency was not affected by treatments (average 1.61 kg/kg; SEM = 0.04). Concentrations of milk fat, true protein, and lactose (average 3.50, 3.03, and 4.84%, respectively) and energy-corrected milk yield (average 38.1 kg/d) were not different (P ≥ 0.38) among treatments. Milk urea nitrogen was also not affected (P = 0.39) by treatment. Treatments had no effect (P ≥ 0.17) on enteric methane (average 344 g/d, SEM = 16.2) or carbon dioxide emission and methane yield (average 13.8 g/kg DMI; SEM = 0.56) or intensity (9.5 g/kg ECM; SEM = 0.49). In this experiment, the Saccharomyces cerevisiae-based microbial product increased milk production without affecting enteric methane emission. The fungal enzyme product had no effect on productivity or gas emission.

Key Words: direct-fed microbial, fungal enzyme, methane