AUTHOR=Zhao Yabo , Zhang Yanmei , Khas Erdene , Ao Changjin , Bai Chen 

TITLE=Effects of Allium mongolicum Regel ethanol extract on three flavor-related rumen branched-chain fatty acids, rumen fermentation and rumen bacteria in lambs

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.978057

DOI=10.3389/fmicb.2022.978057

ISSN=1664-302X

ABSTRACT=<p>The objective of this study was to evaluate the effect of <italic>Allium mongolicum</italic> Regel ethanol extract (AME) on the concentration of three branched-chain fatty acids (BCFAs) related to flavor, fermentation parameters and the bacteria and their correlations in the rumen of lambs. A total of thirty 3-month-old male, Small-tailed Han sheep (33.60 ± 1.23 kg) were randomly distributed into 2 groups as follows: control group (CON) was fed a basal diet and AME group was fed a basal diet supplemented with 2.8 g⋅lamb<sup>–1</sup>⋅d<sup>–1</sup><italic>A. mongolicum</italic> Regel ethanol extract. AME supplementation decreased (<italic>P</italic> = 0.022) 4-methyloctanoic acid (MOA) content and tended to lower (<italic>P</italic> = 0.055) 4-methylnonanoic acid (MNA) content in the rumen. Compared to CON group, the ruminal concentrations of valerate and isovalerate were higher (<italic>P</italic> = 0.046 and <italic>P</italic> = 0.024, respectively), and propionate was lower (<italic>P</italic> = 0.020) in the AME group. At the phylum level, the AME group had a lower abundance of <italic>Bacteroidetes</italic> (<italic>P</italic> = 0.014) and a higher abundance of <italic>Firmicutes</italic> (<italic>P</italic> = 0.020) than the CON group. At the genus level, the relative abundances of <italic>Prevotella</italic> (<italic>P</italic> = 0.001), <italic>Christensenellaceae_R-7_group</italic> (<italic>P</italic> = 0.003), <italic>Succiniclasticum</italic> (<italic>P</italic> = 0.004), and <italic>Selenomonas</italic> (<italic>P</italic> = 0.001) were significantly lower in the AME group than in the CON group, while the relative abundances of <italic>Ruminococcus</italic> (<italic>P</italic> &lt; 0.001), <italic>Quinella</italic> (<italic>P</italic> = 0.013), and <italic>Lachnospiraceae_XPB1014_group</italic> (<italic>P</italic> = 0.001) were significantly higher. The relative abundances of <italic>Prevotella</italic> (<italic>P</italic> = 0.029, <italic>R</italic> = 0.685; <italic>P</italic> = 0.009, <italic>R</italic> = 0.770), <italic>Christensenellaceae_R-7_group</italic> (<italic>P</italic> = 0.019, <italic>R</italic> = 0.721; <italic>P</italic> = 0.029, <italic>R</italic> = 0.685), and <italic>Succiniclasticum</italic> (<italic>P</italic> = 0.002, <italic>R</italic> = 0.842; <italic>P</italic> = 0.001, <italic>R</italic> = 0.879) was positively correlated with MOA and MNA levels, and the relative abundance of <italic>Lachnospiraceae_XPB1014_group</italic> (<italic>P</italic> = 0.033, <italic>R</italic> = −0.673) was negatively correlated with MOA. The relative abundance of <italic>Christensenellaceae_R-7_group</italic> (<italic>P</italic> = 0.014, <italic>R</italic> = −0.744) and <italic>Prevotellaceae_UCG-003</italic> (<italic>P</italic> = 0.023, <italic>R</italic> = −0.706) correlated negatively with the EOA content. In conclusion, these findings suggest that the AME affected the concentration of BCFAs, fermentation parameters and the rumen bacteria in the rumen of lambs.</p>