Effect of corn stover pellet feed replacing partial silage on rumen microflora and serum metabolome of breeding cow

Chenyue Jiao changze cui ^* youpeng qi ^* meixian zhang ^* pengcheng zhao ^* shaopeng chen ^* Xiangyan Wang jiang hu ^* bingang shi ^* ting liu ^* Zhidong Zhao fangfang zhao ^*

• Gansu Agricultural University, Lanzhou, China

They were fed under the same feeding conditions for 70 days, of which 8 in the control (CON) group were fed 65% roughage (100% silage) + 35% concentrate, and 10 in the treatment (TRT) group were fed 65% roughage (50% corn stover pellets + 50% silage) + 35% concentrate, and milk quality, serum immunity indexes, serum metabolomes, rumen fermentation parameters, rumen Microorganisms. The results showed that there was no significant difference in production performance between the two groups of breeding cow fed hay and Corn stover pellet feed (p < 0.05); Immunoglobulin A (IgA) was significantly higher in TRT compared to CON (p <0.05), and there was no significant difference in Immunoglobulin G (IgG) and Immunoglobulin M (IgM) between the two groups (p > 0.05); a total of 92 differential metabolites were screened out in the serum metabolomics analysis, among them, L-valine, L-leucine, L-arginine, L-cysteine, L-tyrosine, and L-tryptophan were upregulated; In rumen fermentation parameters there was no significant difference between CON and TRT in rumen pH, rumen ammonia nitrogen ( NH3-N) content, rumen Acetic/Propionic concentration (p > 0.05), and the concentration of Acetic, Propionic, butyric and Total volatile fatty acids (TVFA) in CON was significantly lower than that in TRT (p < 0.05). Among the rumen microorganisms, the dominant groups were Thick-walled Firmicutes, Bacteroidota, Prevotella and Ruminalococcus. In the correlation analysis between rumen fermentation parameters and rumen microorganisms, Propionic and TVFA showed a significant positive correlation with Prevotella (p < 0.05), butyric showed a highly significant positive correlation with Prevotella (p < 0.01), and propionic butyric, and TVFA showed a positive correlation with Bacteroides (p < 0.05); L-cysteine was significantly positively correlated with Prevotella and Anaeroplasma (p < 0.05) and Eubaterium in rumen microbial-serum metabolite correlation analysis (p < 0.01).