AUTHOR=Gong Ruiguang , Song Shengjie , Ai Yaotian , Wang Shuhui , Dong Xianggui , Ren Zhanjun , Xie Hui , Jiang Benmo , Zhao Lixia 

TITLE=Exploring the growing forest musk deer (Moschus berezovskii) dietary protein requirement based on gut microbiome

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1124163

DOI=10.3389/fmicb.2023.1124163

ISSN=1664-302X

ABSTRACT=<p>It is necessary to assess the appropriate dietary protein level of the forest musk deer (FMD), as nutritional needs are unclear. The microbiome in gastrointestinal tracts plays an important role in regulating nutrient utilization, absorption and host growth or development. Thus, we aimed to evaluate growth performance, nutrient digestibility and fecal microbiome of growing FMD supplied with different protein levels of diets. Eighteen 6-month-old male FMD with an initial weight 5.0 ± 0.2 kg were used in a 62-day trial. The animals were randomly distributed to three groups, the dietary crude protein (CP) level was 11.51% (L), 13.37% (M), and 15.48% (H). The results showed that the CP digestibility decreased as dietary CP level increased (<italic>p</italic> &lt; 0.01). Compared with group L and H, FMD in M group has higher average daily gain, feed efficiency and neutral detergent fiber digestibility. For the fecal bacterial community, the percentage of Firmicutes was increased, Bacteroidetes was decreased and the diversity of microbiota significantly reduced (<italic>p</italic> &lt; 0.05) with the increasing of dietary protein. The proportion of <italic>Ruminococcaceae_005</italic>, <italic>Ruminococcaceae_UCG-014</italic> and <italic>uncultured_bacterium_f_Lachnospiraceae</italic> were significantly increased wtih rising CP, the proportions of <italic>Bacteroides</italic> and <italic>Rikenellaceae_RC9_gut_grou</italic>p were significantly decrease nevertheless at the genus level. The higher abundance of <italic>f_Prevotellaceae</italic> and <italic>g_Prevotellaceae_UCG_004</italic> were found at M group by LEfSe analysis. The relative abundance of <italic>uncultured_bacterium_f_Ruminococcaceae</italic> was positively correlated with the average daily gain and feed conversion ratio (<italic>p</italic> &lt; 0.05), whereas <italic>Family_XIII_AD3011_group</italic> was negatively correlated with feed conversion ratio (<italic>p</italic> &lt; 0.05). The UPGMA tree showed L and M groups were closer in clustering relationship, while H group was clustered separately into a branch, which indicated that the bacterial structure had changed greatly with protein level increased from 13.37 to 15.48%. Overall, our results indicated that the optimum dietary CP for the growing FMD was 13.37%.</p>