小酸模入侵对人工草地植被、放牧黑山羊生长性能、瘤胃发酵参数以及血清指标的影响OA北大核心CSTPCD

The purpose of this study was to explore the effects of Rumex acetosella invasion on the growth performance,rumen fermentation parameters and serum indexes of the main vegetation and grazing black goats in the artificial grassland.In Weining County,Guizhou Province,four artificial grasslands with different invasion degrees of Rumex acetosella were selected,and the main vegetation density and height of different grasslands were analyzed.A total of 120 male lambs were selected with an average weight of(22.69±1.43)kg.According to the complete randomization block design,the goats were randomly divided into four groups with three replicates per group and 10 goats per replicate.The black goats in each group were naturally grazed in four artificial grasslands for three months,and the rumen fermentation parameters and serum indexes were analyzed.The results showed that with the increase of the density of Rumex acetosella in the artificial grassland,the density and height of duck grass and white clover gradually decreased.The average daily gain of naturally grazing black goats in group Ⅱ was significantly higher than that in group Ⅳ(P＜0.05).The content of total volatile fatty acids in the rumen of black goats in group Ⅳ was significantly lower than that in group Ⅱ and group Ⅲ(P＜0.05).The rumen butyric acid content of black goats in group Ⅰ was the highest,but the contentrations of acetic acid and propionic acid were lower than those in the other three groups.In the group Ⅳ,the serum alanine aminotransferase(ALT)and aspartate aminotransferase(AST)contentrations were the highest,and the growth hormone(GH)content was the lowest.The serum immunoglobulin G(IgG)and immunoglobulin M(IgM)levels in group Ⅳ were significantly lower than those in other groups(P＜0.05),and the contentrations of tumor necrosis factor-α(TNF-α)and interleukin-2(IL-2)were higher than those in the other three groups.The serum glutathione peroxidase(GSH-Px)activity of black goat in group Ⅰ was significantly lower than that in other three groups(P＜0.05),and the content of malondialdehyde(MDA)was significantly higher than that in other groups(P＜0.05).The result shows that the rumen fermentation function,immunity and growth performance of grazing black goats are decreased when the density of Rumex acetosella reaches 560 plants/m2.