Effects of cotton straw and apple pomace mixed ensilage on growth performance, slaughter performance, meat quality, rumen microbiota and metabolome of Xinjiang Brown cattle.

Abstract

This study aimed to investigate the effects of replacing traditional corn silage with cotton straw and apple pomace mixed ensilage feed on the growth performance, slaughter performance, meat quality, rumen microbiota and metabolome of Xinjiang Brown Cattle. Twenty 22-month-old Xinjiang Brown Cattle with similar body conditions were randomly divided into a control group (Con, corn silage) and an experimental group (Tre, cotton straw and apple pomace mixed ensilage). The experiment lasted for 180&#x202f;days, during which growth performance was evaluated. At the end of the experiment, 6 cattle were randomly selected from each group for slaughter to determine slaughter performance and meat quality. Meanwhile, rumen fluid samples were collected to analyze the rumen microbial community structure using 16S rRNA gene sequencing, and rumen fluid metabolites were analyzed with untargeted metabolomics (LC-MS) technology. The results showed that there were no significant differences in growth performance (average daily gain and final weight) between the two groups. However, compared to the Con group, the carcass weight, dressing percentage and drip loss of the Tre group were significantly decreased (&#x202f;<&#x202f;0.05). Rumen fermentation results indicated that the rumen pH value of the Tre group was significantly increased (&#x202f;<&#x202f;0.05), while the acetic acid content was significantly decreased (&#x202f;<&#x202f;0.05). Microbiome analysis showed that the-diversity (andindices) of rumen microbiota in the Tre group was significantly higher, and there was a significant difference in-diversity (&#x202f;<&#x202f;0.05); the relative abundance of fiber-degrading bacteria such asin the Tre group was significantly increased. LC-MS analysis revealed that the contents of beneficial metabolites such as N-Acetyl-L-methionine and Resveratrol were increased in the Tre group. In conclusion, cotton straw and apple pomace mixed ensilage feed can be used as an effective substitute for corn silage, modulating the rumen microbial community structure and altering the metabolite profile, thereby improving meat juiciness. This study provides theoretical support for the resourceful and high-value utilization of agricultural by-products such as cotton straw and fruit pomace in Xinjiang.