Effect of Potato Vine and Leaf Mixed Silage to Whole Corn Crops on Rumen Fermentation and the Microbe of Fatten Angus Bulls

The objective of this study was to evaluate the effects of potato vine and leaf mixed silage (PVS) on rumen fermentation and the microbe in ruminants and to improve the utilization of PVS resources in ruminants through in vitro gas production and feeding trials. The experiment was divided into three groups: PVS1 (50% corn + 50% potato vine and leaf silage), PVS2 (75% potato vine and leaf + 15% rice straw + 10% cornmeal silage) and whole-plant corn silage (CS). The in vitro gas production results showed that there was a significant reduction in PVS groups in the indexes of total gas (<i>p</i> < 0.05) and CH₄ production (<i>p</i> < 0.05). The digestibility of dry matter (<i>p</i> < 0.05), neutral detergent fiber (NDF) (<i>p</i> < 0.05), and acid detergent fiber (ADF) (<i>p</i> < 0.05) at 48 h were decreased in the PVS group. For the rumen fermentation indexes, the pH (<i>p</i> < 0.05), microbial crude protein (MCP) (<i>p</i> < 0.05), and acetate to propionate (<i>p</i> < 0.05) showed an increase in the PVS group, but a decrease in the total volatile fatty acid concentration (<i>p</i> < 0.05). In the feeding trial, different silages in diets had no significant effect on the rumen fermentation indexes (<i>p</i> > 0.05). In the rumen microbe composition, the PVS diet significantly reduced the abundance of Prevotella (<i>p</i> < 0.05) compared with the CS diet group. The PVS2 diet significantly increased the abundance of the <i>Lachnospiraceae_XPB1014_group</i> (<i>p</i> < 0.05) and <i>Bacteroidales_bacterium_Bact_22</i> (<i>p</i> < 0.05) compared with the CS diet group. In conclusion, PVS had no negative effect on rumen fermentation characteristics and rumen microbial flora and could significantly reduce rumen gas production compared to CS, positively mitigating animal husbandry CH₄ emissions and environmental protection.