Jun-Hu  Yao, Chao-Yun  Li, Yang-Chun  Cao, Shi-Zhao  Li, Ming  Xu, Chan-Juan  Liu, Zhi-Peng  Yu, Xiang-Hui  Zhao, 
    Effects of Exogenous Fibrolytic Enzyme on <I>in vitro</I> Ruminal Fermentation 
  and Microbial Populations of Substrates with Different Forage to Concentrate Ratios,
    Journal of Animal and Veterinary Advances,
    Volume 12,Issue 10,
    2013,
    Pages 1000-1006,
    ISSN 1680-5593,
    javaa.2013.1000.1006,
    (https://makhillpublications.co/view-article.php?doi=javaa.2013.1000.1006)
    Abstract: This research was conducted to investigate the effects of 
  exogenous fibrolytic enzyme on <I>in vitro</I> ruminal fermentation and microbial 
  populations with substrates in different Forage to Concentrate ratios (F:C). 
  Four levels (0, 40, 80 and 120 U g<SUP>-1</SUP> dry matter substrate) of fibrolytic 
  enzyme were supplemented to buffered rumen fluid and incubated with three different 
  F:C ratios (80:20, 50:50 and 20:80) substrates at 39&deg;C. After 24 h incubation, 
  the results showed that in three different F:C ratios, fibrolytic enzyme significantly 
  increased (p&lt;0.001) total gas production, <I>in vitro</I> dry matter disappearance, 
  concentration of total volatile fatty acid and molar proportion of propionate 
  and decreased (p&lt;0.001) pH but it did not significantly (p&gt;0.05) affect 
  molar proportion of butyrate. And in the high (F:C 80:20) and medium (F:C 50:50) 
  forage substrates, fibrolytic enzyme increased (p&lt;0.05) the molar proportion 
  of propionate and decreased (p&lt;0.05) the ratio of acetate to propionate but 
  the effects did not observed in high concentrate (F:C 20:80) substrates. It 
  was also found that fibrolytic enzyme increased (p&lt;0.05) the number of <I>Fibrobacter 
  succinogenes</I> and methanogens in the F:C 80:20 substrate but there was no 
  significant (p&gt;0.05) effects on microbial populations in the F:C 50:50 and 
  20:80 substrates. The results indicated that the fibrolytic enzyme improved 
  the degradation of substrates and had different effects on the ruminal fermentation 
  pattern and microbial populations under three F:C ratio substrates. The efficiency 
  of fibrolytic enzyme on high and medium forage substrates was greater than low 
  forage substrates.
    Keywords: Exogenous fibrolytic enzyme;ruminal fermentation;forage to concentrate;in vitro;microbial populations