Abstract
This study was conducted to investigate the effects of Momordica charantia saponin (MCS) on ruminal fermentation of maize stover and abundance of selected microbial populations in vitro. Five levels of MCS supplements (0, 0.01, 0.06, 0.30, 0.60 mg/mL) were tested. The pH, NH3-N, and volatile fatty acid were measured at 6, 24, 48 h of in vitro mixed incubation fluids, whilst the selected microbial populations were determined at 6 and 24 h. The high dose of MCS increased the initial fractional rate of degradation at t-value = 0 (FRD0) and the fractional rate of gas production (k), but decreased the theoretical maximum of gas production (VF) and the half-life (t0.5) compared with the control. The NH3-N concentration reached the lowest concentration with 0.01 mg MCS/mL at 6 h. The MSC inclusion increased (p<0.001) the molar proportion of butyrate, isovalerate at 24 h and 48 h, and the molar proportion of acetate at 24 h, but then decreased (p<0.05) them at 48 h. The molar proportion of valerate was increased (p<0.05) at 24 h. The acetate to propionate ratio (A/P; linear, p<0.01) was increased at 24 h, but reached the least value at the level of 0.30 mg/mL MCS. The MCS inclusion decreased (p<0.05) the molar proportion of propionate at 24 h and then increased it at 48 h. The concentration of total volatile fatty acid was decreased (p<0.001) at 24 h, but reached the greatest concentration at the level of 0.01 mg/mL and the least concentration at the level of 0.60 mg/mL. The relative abundance of Ruminococcus albus was increased at 6 h and 24 h, and the relative abundance of Fibrobacter succinogenes was the lowest (p<0.05) at 0.60 mg/mL at 6 h and 24 h. The relative abundance of Butyrivibrio fibrisolvens and fungus reached the greatest value (p<0.05) at low doses of MCS inclusion and the least value (p<0.05) at 0.60 mg/mL at 24 h. The present results demonstrates that a high level of MCS quickly inhibits in vitro fermentation of maize stover, while MCS at low doses has the ability to modulate the ruminal fermentation pattern by regulating the number of functional rumen microbes including cellulolytic bacteria and fungi populations, and may have potential as a feed additive applied in the diets of ruminants.
Highlights
Saponins are the most commonly studied phytochemicals as feed additives
The molar proportions of any individual vitro fermentation and chemical analyses (VFA), the concentration of tVFA and the acetate to propionate ratio (A/P) ratio were not affected by MCS compared with the control for all doses at 6 h
The current study showed reduced the degradation of substrate by bacteria and that MSC inclusion increased the molar proportions of resulted in the reduction of gas production (GP) (Wina et al, 2006)
Summary
Saponins are the most commonly studied phytochemicals as feed additives. Recent studies have demonstrated that saponins have the potential to modulate rumen fermentation, such as increasing total volatile fatty. The molar proportions of any individual VFA, the concentration of tVFA and the A/P ratio were not affected by MCS compared with the control for all doses at 6 h. F. succinogenes, Fibrobacter succinogenes; R. albus, Ruminococcus albus; B. fibrisolvens, Butyrivibrio fibrisolvens; R. flavefaciens, Ruminococcus flavefaciens; VFA, volatile fatty acid; VF, the theoretical maximum of gas production; FRD0, the initial fractional rate of degradation; t0.5, the time at which half of the final gas production; tVFA, total VFA; A/P, acetate to propionate ratio. Showed no significant correlations with molar proportions On the contrary, MCS inclusion increased the molar of any individual VFA, or the concentration of tVFA. Proportion of propionate and decreased the proportion of acetate, which led to a lower A/P ratio at 48 h of incubation
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
