abstract: This study was conducted to investigate the effect of @entity3 meal (SM) and @entity8 ( @entity8 ) on biogenic @entity6 production and microbial diversity using in vitro ruminal fermentation. Treatments comprised of incubation of 2 g of mixture (expressed as 10 parts) containing different ratios of SM to @entity8 as: 0:0, 10:0, 7:3, 5:5, 3:7, or 0:10. In vitro ruminal fermentation parameters were determined at 0, 12, 24, and 48 h of incubation while the biogenic @entity6 and microbial diversity were determined at 48 h of incubation. Treatment with highest proportion of SM had higher (p<0.05) gas production than those with higher proportions of @entity8 . Samples with higher proportion of @entity8 resulted in lower pH than those with higher proportion of SM after 48 h of incubation. The largest change in NH3-N concentration from 0 to 48 h was observed on all SM while the smallest was observed on exclusive @entity8 . Similarly, exclusive @entity8 had the lowest NH3-N concentration among all groups after 24 h of incubation. Increasing @entity0 ( @entity1 ) concentrations were observed with time, and @entity1 concentrations were higher (p<0.05) with greater proportions of SM than @entity8 . Balanced proportion of SM and @entity8 had the highest (p<0.05) total volatile @entity2 (TVFA) while propionate was found highest in higher proportion of @entity8 . Moreover, biogenic @entity6 (BA) was higher (p<0.05) in samples containing greater proportions of SM. Histamines, @entity6 index and total @entity5 were highest in exclusive SM followed in sequence mixtures with increasing proportion of @entity8 (and lowered proportion of SM) at 48 h of incubation. Nine dominant bands were identified by denaturing gradient gel electrophoresis (DGGE) and their identity ranged from 87% to 100% which were mostly isolated from rumen and feces. Bands R2 ( @entity7 clone RB-5E1) and R4 ( @entity7 rumen bacterium clone L7A_C10) bands were found in samples with higher proportions of SM while R3 ( @entity7 Firmicutes bacterium clone NI_52), R7 ( @entity9 sp. MCB2), R8 ( @entity9 gene) and R9 ( @entity9 LongY6) were found in samples with higher proportions of @entity8 . Different feed ratios affect rumen fermentation in terms of pH, NH3-N, @entity1 , BA, volatile @entity2 and other metabolite concentrations and microbial diversity. Balanced protein and @entity4 ratios are needed for rumen fermentation.
  