Effects of Encapsulated γ-Aminobutyric Acid on Serum Biochemical Indexes,Nutrient Apparent Digestibility and Rumen Fermentation Function of Lambs during Weaning Stress Period
In this study,we investigated the effects of encapsulated γ-aminobutyric acid(GABA)on serum biochemical indexes,nutrients apparent digestibility and rumen fermentation in lambs during weaning stress pe-riod.Forty-eight healthy 45 days Hu lambs with similar body weight(26.14±1.40)kg were randomly assigned into 4 groups(4 replicates per group and 3 lambs per replicate).The lambs in control group(CON group)were fed a basal diet,and the others in experimental groups Ⅰ,Ⅱ and Ⅲ were fed the basal diet supplemen-ted with 100,140 and 180 mg/d encapsulated GABA,respectively.All lambs were weaned at 48 days of age(day 1 of experiment),and blood was collected on days-3,1,3,7 and rumen fluid on days-3,1,3,7,14.The digestive experiment was performed on the day 14.The experiment lasted for 21 days.The results showed as follows:1)compared with the CON group,the addition of encapsulated GABA significantly de-creased the serum contents of interferon-γ(IFN-γ),interleukin-6(IL-6),and tumor necrosis factor-α(TNF-α)in lambs(P＜0.05),and significantly increased the serum interleukin-4(IL-4)content(P＜0.05).Time significantly affected serum IFN-γ,IL-4,IL-6 and TNF-α contents in lambs(P＜0.05),with the increase of time,the changes of serum contents of IFN-γ,IL-4,IL-6 and TNF-α in the all groups showed a tendency of increasing and then decreasing.2)Compared with the CON group,the addition of encapsulated GABA could significantly decrease serum D-lactic acid(D-LA)content and diamine oxidase(DAO)activity of lambs(P＜0.05).The DAO activity in the serum of lambs in groups Ⅱ and Ⅲ was significantly lower than that in the control group and group Ⅰ(P＜0.05).Time could significantly affect the D-LA content and DAO activity in serum of lambs(P＜0.05),with the extension of time,serum D-LA content increased first and then de-creased,and serum DAO activity increased first and then decreased in control group and group Ⅰ.3)The ap-parent digestibility of dry matter(DM)and neutral detergent fiber(NDF)in group Ⅱ was significantly higher than that in the other three groups(P＜0.05),and there was no difference between groups Ⅰ and Ⅲ(P＞0.05).The apparent digestibility of acid detergent fiber(ADF)in group Ⅱ was significantly higher than that in group Ⅰ(P＜0.05),and that in group Ⅰ was significantly higher than that in group Ⅲ(P＜0.05).The ap-parent digestibility of crude protein(CP)and ether extract(EE)in groups Ⅱ and Ⅲ was significantly higher than that in group Ⅰ and CON group(P＜0.05).4)The addition of encapsulated GABA was no significant difference in the rumen fermentation parameters among the groups(P＞0.05).Time could significantly affect the rumen pH,NH3-N,total volatile fatty acids(TVFA),acetic acid,propionic acid contents and acetate/propionate of lambs(P＜0.05).pH first increased and then decreased,NH3-N,TVFA acetic acid and propi-onic acid contents first increased,then temporarily decreased and then increased,and the acetate/propionate gradually decreased.Above all,the addition of encapsulated GABA can significantly reduce the serum inflam-mation contents of lambs during weaning stress period,relieve intestinal stress injury,improve rumen fermenta-tion function and increase the apparent digestibility of nutrients.Under the conditions of this test,the optimal addition level of encapsulated GABA is 140 mg/d.[Chinese Journal of Animal Nutrition,2024,36(7):4508-4520]
万方数据
维普
