ABSTRACT: The purpose of this study was to determine the effects of normal diet feed (NF) and alternative diet feed (AF) on animal performance, gene expression in adipose, liver, and muscle, and changes in bacteria and fungi in the rumen of Bos-Taurus using high-throughput sequencing methods. In addition, Interactions between differentially expressed genes (DEGs) in major metabolic organs and rumen bacteria /fungi were studied. A total of 34,360 genes were found to be expressed across all tissues examined based on transcriptome analysis. According to our findings, 34, 36, 28 genes were differentially expressed in the adipose, liver, and muscle tissues, respectively. A majority of DEGs identified were related to osteoclast differentiation, phagosomes, and immune-functions etc. A study of rumen samples revealed that Firmicutes and Bacterioidetes were the most common phyla. An AF diet significantly increased Firmicutes abundance and reduced Bacterioidetes abundance (p< 0.05). Genus-level analysis revealed that the occurrence of Faecalicatena, Intestinimonas, Lachnoclostridium, Faecalicatena, and Intestinimonas was higher (p < 0.05) in animals fed with the AF diet than in animals fed with an NF diet. As for fungi, Neocallimastigomycota accounted for 98.2% of the NF diet and 86.88% of the AF diet. The AF increased the abundance of Orpinomyces (21.15% to 29.7%), Piromyces (0.1% to 1.8%), and other fungi, but reduced the abundance of Neocallimastix (72.0% to 25.2%). Analysis of the correlation between DEGs and microbes showed that rumen bacteria/fungi significantly influenced expression levels of genes in adipose, liver, and muscle tissues
