Abstract #W165
Section: Ruminant Nutrition (posters)
Session: Ruminant Nutrition: Ruminal Fermentation and Gas Production
Format: Poster
Day/Time: Wednesday 7:30 AM–9:30 AM
Location: Exhibit Hall A
Session: Ruminant Nutrition: Ruminal Fermentation and Gas Production
Format: Poster
Day/Time: Wednesday 7:30 AM–9:30 AM
Location: Exhibit Hall A
# W165
Effect of enzyme extracts from Aspergillus oryzae and Aspergillus niger on rumen bacterial and fungal diversity and fermentation in vitro.
K. Nedelkov1,2, S. E. Räisänen*1, X. Chen1,3, M. T. Harper1, A. Melgar1, J. Oh1, D. M. Paulus Compart4, A. N. Hristov1, 1The Pennsylvania State University, University Park, PA, 2Faculty of Veterinary Medicine, Trakia University, Stara Zagora, Bulgaria, 3University of Ulster, Belfast, UK, 4PMI, Arden Hills, MN.
Key Words: enzyme extract, rumen fermentation, in vitro
Effect of enzyme extracts from Aspergillus oryzae and Aspergillus niger on rumen bacterial and fungal diversity and fermentation in vitro.
K. Nedelkov1,2, S. E. Räisänen*1, X. Chen1,3, M. T. Harper1, A. Melgar1, J. Oh1, D. M. Paulus Compart4, A. N. Hristov1, 1The Pennsylvania State University, University Park, PA, 2Faculty of Veterinary Medicine, Trakia University, Stara Zagora, Bulgaria, 3University of Ulster, Belfast, UK, 4PMI, Arden Hills, MN.
The effect of enzyme extracts (ENZ) from Aspergillus oryzae and Aspergillus niger on rumen bacterial and fungal diversity and fermentation variables was investigated in a batch culture in vitro experiment. ENZ was tested at 5 inclusion levels, equivalent to 0, 4, 8, 12, and 16 g ENZ/head/d, calculated based on 25 kg/head/d dry matter (DM) intake. Replicated incubations were conducted for 0, 3, 6, 12, 18, and 24 h. Gas production and composition, pH, volatile fatty acids (VFA), ammonia, neutral-detergent fiber (NDF) degradability, and bacterial and fungal quantities and diversity data were collected. Samples were analyzed for fermentation variables using routine procedures, and bacterial and fungal quantities and diversity were assayed by MR DNA Molecular Research (Shallowater, TX) using qPCR and bTEFAP technologies. Data were analyzed with the MIXED procedure of SAS as repeated measures [with ar(1) covariance structure], using orthogonal polynomial contrasts. The model included incubation, treatment, incubation time, and interactions. Gas production (average 30.7 mL/g feed DM; SEM = 1.58), methane concentration (average 4.50%; SEM = 0.522), and pH (average 6.41; SEM = 0.016) were not affected (P ≥ 0.19) by ENZ. Concentration of total VFA decreased linearly (P < 0.001; from 69.8 to 67.4 mM, SEM = 0.63) with increasing ENZ dose. Molar proportions of acetate, butyrate, and iso-valerate were also decreased (P ≤ 0.02) by ENZ. NDF degradability linearly decreased (P < 0.001; from 63.7 to 54.8%, SEM = 1.53) with increasing ENZ inclusion rate. ENZ had no effect (P ≥ 0.82) on bacterial and fungal quantities (qPCR). The proportion of bacterial genera Treponema and Porphyromonas and fungal genus Neocallimastix were linearly decreased (P ≤ 0.03) by ENZ. No other effects of treatment on bacterial and fungal diversity were observed. In the conditions of this in vitro batch culture experiment, the combination of enzyme extracts from A. oryzae and A. niger had negligible effect on bacterial and fungal quantities and diversity but appeared to inhibit rumen fermentation and NDF degradability.
Key Words: enzyme extract, rumen fermentation, in vitro
