沙棘嫩枝叶对绵羊瘤胃发酵特性和血清免疫指标的影响

Shoots and Leaves of Sea Buckthorn: Effects on Rumen Fermentation Characteristics and Serum Immune Indices of Sheep

本试验旨在研究沙棘嫩枝叶对绵羊瘤胃发酵特性和血清免疫指标的影响。采用单因素随机区组试验设计,选择体重为(28.0±3.5)kg的阿勒泰羔羊60只,随机分成4组,每组3个重复,每个重复5只。对照(Con)组饲喂基础饲粮,试验组以2.5%(SJZY-1组)、5.0%(SJZY-2组)和7.5%沙棘嫩枝叶(SJZY-3组)等量替换基础饲粮中麦秸。试验期63 d,其中预试期7 d,正试期56 d。在正试期第56天晨饲前,分别从各组每个重复随机选取2只,采集血样和瘤胃液。结果表明:1)SJZY-1组和SJZY-3组平均日增重显著高于Con组(P<0.05)。2)随沙棘嫩枝叶添加量的增加,瘤胃液pH呈下降趋势,组间无显著差异(P>0.05);试验组乙酸、丙酸、丁酸和总挥发性脂肪酸(TVFA)的浓度均极显著高于Con组(P<0.01),SJZY-3组最高;乙酸/丙酸和乙酸/TVFA没有显著变化(P>0.05);SJZY-2组和SJZY-3组氨态氮浓度分别显著(P<0.05)和极显著(P<0.01)低于Con组。3)与Con组相比,沙棘嫩枝叶的添加对血清CD4、白细胞介素1(IL-1)、白细胞介素2(IL-2)浓度的影响为低量抑制中、高量促进,而对血清γ干扰素(γ-IFN)浓度的影响则表现为低量促进。结果提示,沙棘嫩枝叶能提高绵羊平均日增重,增加瘤胃液中挥发性脂肪酸浓度和降低氨态氮浓度,提高血清CD4、IL-1、IL-2、γ-IFN浓度;综合考虑,建议沙棘嫩枝叶在绵羊饲粮中以5.0%~7.5%添加。

This experiment was conducted to study the effects of shoots and leaves of sea buckthorn on rumen fermentation characteristics and serum immune indices of sheep. A single factor random block design was used, and sixty healthy Altay lambs with the body weight of （28.0±3.5） kg were selected and randomly divided into 4 groups with 3 replicates in each group and 5 lambs per replicate. Lams in control （Con） group were fed a basal diet, and wheat straw in the basal diet was replaced by shoots and leaves of sea buckthorn at 2.5% （SJZY-1 group） , 5.0% （SJZY-2 group） and 7.5% （SJZY-3 group） , respectively, in test groups. Trial lasted for 63 days, which consisted of a γ-day-pretrial and a 56-day-formal trial. On day 56 of formal trial, two lambs per replicate in each group were randomly selected to collect blood and rumen fluid samples before morn- ing feeding. The results showed as follows： 1 ） average daily gain in SJZY-1 and SJZY-3 groups was signifi- cantly higher than that in Con group （P〈0.05）. 2） Rumen fluid pH tended to be decreased with the increase of supplemental level of shoots and leaves of sea buckthorn, but no significant difference was found among groups （P〉0.05） ; the concentrations of acetic acid, propionic acid, butyric acid and total volatile fatty acids （TV- FA） in test groups were significantly higher than those in Con group （P〈0.01） , and SJZY-3 group had the highest values; acetic acid/propionic acid and acetic acid/TVFA were not significantly changed （P〉0.05） ; compared with Con group, ammonia nitrogen （NH^-N） concentration in SJZY-2 （ P 〈 0.05 ） and SJZY-3 groups （P〈0.01） was significantly decreased. 3） Compared with Con group, the effects of the supplementa- tion of shoots and leaves of sea buckthorn on serum CD4, interleukin-1 （IL-1） and interleukin-2 （IL-2） con- centrations were low-dose inhibition and medium and high-dose stimulation, while the effect on serum γ-inter- feron （γ-IFN） was low-dose stimulation. The results indicate that shoots and leaves of sea buckthorn can im- prove average daily gain, increase volatile fatty acid concentrations and reduce NH3-N concentration in rumen fluid, and increase serum CD4, IL-1, IL-2 and -γ-IFN concentrations; the recommended supplemental level of shoots and leaves of sea buckthorn is 5.0% to 7.5% in diet for sheep.