葡聚糖与聚谷氨酸对围产期奶山羊瘤胃发酵参数、微生物区系及代谢组的影响OA

This experiment was conducted to investigate the effects of dextran and polyglutamic acid on rumen fermentation parameters,microbial flora and metabolome of perinatal dairy goats.Eighteen healthy primiparous Saanen dairy goats in late pregnancy with similar body weight[(40.00±1.73)kg]were randomly divided into 3 groups(6 goats per group):a high-dose group(HI group),a low-dose group(LO group)and a control group(CON group).Goats in the HI group were orally administered with 3 g dextran+20 g polyglutamic acid per day,those in the LO group were orally administered with 1.5 g dextran+10 g polyglutamic acid per day,and those in the CON group were orally administered with the same volume of normal saline per day.The con-tinuous oral administration lasted for 42 days(21 days before parturition and 21 days after parturition).Rumen fluid samples were collected on day 1 and day 21 postpartum for the determination of rumen fermentation pa-rameters,microbial flora and metabolome.The results showed as follows:1)on day 21 postpartum,the valer-ic acid content in rumen fluid of the LO group and HI group was significantly higher than that of the CON group(P＜0.05),the butyric acid content tended to be higher than that of the CON group(P=0.057),and the ammonia nitrogen content tended to be lower than that of the CON group(P=0.073).On day 21 postpar-tum,there were no significant differences in all rumen fermentation parameters among the three groups(P＞0.05).2)On day 21 postpartum,the α diversity indexes of rumen microbiota(except Goods_coverage in-dex)in the HI group were higher than those in the CON group and LO group,but the differences were not sig-nificant(P＞0.05).On day 21 postpartum,the proportion and abundance of Prevotella in rumen of the HI group were higher than those in the CON group and LO group.The two significantly different microbial predic-tive functions with the highest enrichment degree in the HI group were RNA polymerase and biosynthesis of un-saturated fatty acids.On day 21 postpartum,the differential microorganisms between the HI group and CON group showed significant differences in the functions of Staphylococcus aureus infection and ECM-receptor in-teraction(P＜0.05).3)On day 21 postpartum,compared with the CON group,the significantly up-regulated differential metabolites in rumen fluid of the HI group included 4,4′-diaminodibutylamine classified as hetero-cyclic compounds,pyridoxamine-5′-phosphate classified as organic acids and their derivatives,and L-methio-nine sulfoxide classified as amino acids and their metabolites(P＜0.05);the significantly down-regulated dif-ferential metabolites included 4-(3-methylbutoxy)aniline hydrochloride classified as benzene and its deriva-tives,trans-2-hexenal dimethyl acetal,and Trp-Ile classified as amino acids and their metabolites(P＜0.05).The metabolic pathways with high significant differences between the two groups were cysteine and methionine metabolism and inflammatory mediator regulation of TRP channels.In conclusion,oral administration of dex-tran and polyglutamic acid can promote the rumen fermentation function,increase the proportion and abundance of rumen dominant microbiota,and improve the abundance of energy-supplying nutrient metabolites in the ru-men of perinatal dairy goats.[Chinese Journal of Animal Nutrition,2026,38(3):2068-2085]