Multi-Omics Analysis of the Mechanism of Mentha Haplocalyx Briq on the Growth and Metabolic Regulation of Fattening Sheep.

Mentha haplocalyx Briq (MHB) and its components have been proven to improve the growth performance of livestock and poultry. The aim of this experiment was to investigate the effects of MHB addition on growth performance, rumen and fecal microbiota, rumen fluid, serum and urine metabolism, and transcriptomics of rumen epithelial cells in meat sheep. Twelve Hu sheep were selected for the experiment and fed with basic diet (CON) and a basal diet supplemented with 80 g/kg DM of Mentha haplocalyx Briq (MHB). The experimental period was 10 weeks with the first 2 weeks as the pre-trial period. The results showed that compared with the CON group, the average daily weight gain of meat sheep in the MHB group increased by 20.1%; the total volatile fatty acid (VFA) concentration significantly increased ( < 0.05); The thickness of the cecal mucosal layer was significantly reduced ( < 0.01), while the thickness of the colonic mucosal layer was significantly increased ( < 0.05), the length of ileal villi significantly increased ( < 0.01), the thickness of colonic mucosal layer and rectal mucosal muscle layer significantly increased ( < 0.05), and the thickness of cecal mucosal layer significantly decreased ( < 0.05); The serum antioxidant capacity has increased. At the genus level, the addition of MHB changed the composition of rumen and fecal microbiota, increased the relative abundance of Paraprevotella, Alloprevotella, Marinilabilia, Saccharibacteria_genera_incertae_sedis, Subdivision5_genera_incertae_sedis and Ornatilinea in rumen microbiota, and decreased the relative abundance of Blautia ( < 0.05). The relative abundance of Prevotella, Clostridium XlVb and Parasutterella increased in fecal microbiota, while the relative abundance of Blautia and Coprococcus decreased ( < 0.05). There were significant differences in the concentrations of 105, 163, and 54 metabolites in the rumen, serum, and urine between the MHB group and the CON group ( < 0.05). The main metabolic pathways of the differences were pyrimidine metabolism, taurine and taurine metabolism, glyceride metabolism, and pentose phosphate pathway ( < 0.05), which had a significant impact on protein synthesis and energy metabolism. The transcriptome sequencing results showed that differentially expressed genes were mainly enriched in immune regulation, energy metabolism, and protein modification. Therefore, adding MHB improved the growth performance of lambs by altering rumen and intestinal microbiota, rumen, serum and urine metabolomics, and transcriptome.