This study was to investigate the effects of live or autoclaved Bacillus subtilis natto, their fermented products and media on rumen fermentation and rumen functional bacteria in vitro. Rumen fluid from three multiparous lactating Holstein cows was combined and transferred into serum bottles after diluted. Fifteen serum bottles were divided into five treatments, which were designed as following: CTR (the fermentation of 0.5 g TMR and ruminal fluids from dairy cows), LBS (CTR plus a minimum of 1011 cfu live Bacillus subtilis natto), ABS (CTR plus a minimum of 1011 cfu autoclaved Bacillus subtilis natto), BSC (CTR plus 1 ml Bacillus subtilis natto fermentation products without bacteria), and BSM (CTR plus 1 ml liquid fermentation medium). When separated from the culture, live Bacillus subtilis natto individually increased the concentrations of ammonia-N (P < 0.01), MCP production (P < 0.01), and tended to elevate total VFA (P = 0.07), but decreased the ratio of acetate and propionate (P < 0.01). Autoclaved Bacillus subtilis natto has the similar function with the live bacteria except for the ratio of acetate and propionate. Except B. fibrisolvens, live or autoclaved Bacillus subtilis natto did not influence or decreased the 16S rRNA gene quantification of the detected bacteria. BSC and BSM altered the relative expression of certain functional bacteria in the rumen. These results indicated that it was Bacillus subtilis natto thalli that played the important role in promoting rumen fermentation when applied as a probiotic in dairy ration. © 2016, Springer Science+Business Media New York.
Tag: fermentation
Rumen liquor from slaughtered cattle as inoculum for feed evaluation
Use of nonlinear mathematical models has been majorly based on in vitro gas production (GP) data generated when substrates are incubated with rumen liquor from fistulated steers. However, existing evidence suggests that rumen liquor from slaughtered cattle of unknown dietary history also generates quantifiable in vitro GP data. Fitting and description of GP data obtained from 4 diets incubated with rumen liquor from slaughtered cattle was evaluated using single-pool exponential model with discrete lag time (EXPL), logistic (LOG), Groot’s (GRTS) and Gompertz (GOMP) models. Diets were formulated by varying proportions of Rhodes grass (Chloris gayana) hay and a concentrate mixed on dry matter basis to be: 1,000 g/kg Rhodes grass hay (RGH) and 0 of the concentrate (D1), 900 g/kg RGH and 100 g/kg concentrate (D2), 800 g/kg RGH and 200 g/kg concentrate (D3), 700 g/kg RGH and 300 g/kg concentrate (D4). Dietary kinetics for the models were determined by measuring GP at 2, 4, 8, 10, 18, 24, 36, 48, 72, 96 and 120 h. Model comparison was based on derived GP kinetics, graphical analysis of observed versus predicted GP profiles plus residual distribution and goodness-of-fit from analysis of root mean square error (RMSE), adjusted coefficient of determination (Adj-R2) and Akaike’s information criterion (AIC). Asymptotic GP, half-life and fractional rate of GP differed (P < 0.001) among the 4 models. The RMSE, Adj-R2 and AIC ranged from 1.555 to 4.429, 0.906 to 0.984 and 2.452 to 15.874, respectively, for all diets compared across the 4 models. Based on the goodness-of-fit statistical criterion, GP profiles of D1 were more appropriately fitted and described by GRTS and GOMP than the EXPL and LOG models. The GRTS model had the lowest AIC value for D2 (2.452). Although GRTS model had the most homogenous residual dispersion for the 4 diets, all the 4 models exhibited a sigmoidal behavior. Therefore, rumen liquor from slaughtered cattle of unknown dietary history can be used to derive nutritionally important feed parameters, but choice of the most appropriate model should be made based on fitting criteria and dietary substrates incubated.
Amla (Phyllanthus emblica) fresh fruit as new feed source to enhance ruminal fermentation and milk production in lactating dairy cows
This study sought to determine the effect of feeding three levels of the novel feedstuff fresh Phyllanthus emblica (amla) fruit on nutrient digestibility, fermentation parameters, and milk production of lactating dairy cows. Eight ruminally cannulated mid-lactation dairy cows were randomly assigned to two treatment groups in a repeated crossover design. There was a 14-d adaptation phase followed by the start of period 1. In this period, the first group of 4 cows received the control diet, whereas the other group was supplemented with FAF at increasing levels (200, 400, 600 g/d), sequentially, at 14-d intervals. Each period consisted of a cow as the main plot, with three different amla doses representing subplots. In period 2, the control and supplemented groups were exchanged. For each sub-period, the first ten days were adjusted for diet adaptation, and the last four days were assigned to sample milk, feed, rumen, and feces. Supplementation of FAF had no effect (P = 0.92) on feed intake. While, the lowest (P < 0.01) rumen protozoa count was recorded at 400 g/d FAF dose compared to other groups. However, total VFA concentrations varied in a quadratic manner (P = 0.04) with increasing FAF doses. The molar proportion of acetate (P = 0.01) and propionate (P < 0.01) were altered (cubic effect). The effects of FAF supplementation on NH3-N concentration (P < 0.001) were dose-dependent, with the concentration decreasing by 54.9% at 200 g/d and increasing by 29.8% at 600 g/d when compared to controls. There was a quadratic effect of FAF on milk yield (P = 0.02), with the 200 and 400 g/d groups producing higher milk yields than the 600 g/d groups. The inclusion of 400 g/d FAF in the diet led to greater milk protein yield (P < 0.01) and milk nitrogen efficiency (P < 0.01) compared to cows fed 200 g/d FAF. Moreover, the concentration of milk urea nitrogen (MUN) was reduced (P < 0.001) with 200 or 400 g/d FAF supplementation compared with control or 600 g/d FAF. When cows were supplemented with a 400 g/d FAF dose, both ruminal protozoa counts and MUN were reduced, but milk protein and nitrogen efficiency were increased with no reduction in milk production. These results suggest that FAF can be used as an alternative natural feed source up to 400 g/d on an as-fed basis, but beyond that there may have anti-nutritional factors that limit the levels of amla supplementation. © 2021 The Authors