Effect of forage ramie and sweet sorghum combination on rumen fermentation in vitro

LI Xi; YU Xia; WU Duan-qin

doi:10.13557/j.cnki.issn1002-2813.2024.21.004

Abstract：This study was conducted to investigate the effects of forage ramie and sweet sorghum combination on rumen fermentation evaluated by simulated rumen fermentation in vitro.Forage ramie and sweet sorghum were composed of five fermentation substrates according to different dry matter ratios based on mass ratio 10∶90(R10 group),20∶80(R20 group),30∶70(R30 group),40∶60(R40 group)and 50∶50(R50 group),respectively.Three adult Liuyang black goats were equipped with permanent rumen fistulas and were selected as rumen fluid donors to conduct 48 h in vitro rumen fermentation.The results showed that with the increase in the proportion of forage ramie,the crude protein content in the forage ramie and sweet sorghum mixture increased,while the content of neutral detergent fiber and total energy gradually decreased.The addition of forage ramie to the feed mixture has no significant effect on ruminal fluid pH,dry matter degradation rate,potential maximum gas production,and gas production rate(P＞0.05).The gas production of R50 group were significantly lower than those of R10,R20 and R30 groups(P＜0.05),the methane production was significantly lower than that of other groups(P＜0.05),but the hydrogen production was significantly higher than that of other groups(P＜0.05).The proportion of forage ramie added had no significant effect on the total content of volatile fatty acids and the ratio of acetic to propionic acids(P＞0.05),but the butyric acid content in the R50 group was significantly lower than that in the R10 group(P＜0.05).The study indicates that forage ramie has a high nutritional value and can serve as a substitute for high-quality forage in ruminant feed.The proportion of ramie should not exceed 20％.