利用体外瘤胃发酵法评价桑叶与羊草的组合效应

摘要

本试验旨在利用体外瘤胃发酵法研究不同比例的桑叶与羊草之间的组合效应,从而筛选出两者之间的最佳组合比例.将桑叶和羊草分别以0:100(T0组)、20:80(T20组)、40:60(T40组)、60:40(T60组)、80:20(T80组)、100:0(T100组)的比例混合后作为底物,进行连续72 h的体外产气培养和体外批次培养试验.结果表明:1)随着底物中桑叶比例的提高,理论产气量、累积产气量、培养液微生物蛋白(MCP)浓度和体外有机物消化率(IVDOM)都有升高的趋势;2)在72 h时,T100组的理论最大产气量、累积产气量和IVDOM都显著高于其他各组(P<0.05),T60和T100组的培养液MCP浓度显著高于其他各组(P<0.05);3)在48和72 h时,T60、T80和T100组培养液pH显著低于其他各组(P<0.05);4)在72 h时,T60、T80和T100组培养液的总挥发性脂肪酸(TVFA)、乙酸浓度没有显著差异(P>0.05),但都显著高于其他各组(P<0.05);5)在6、12和72 h时,T60、T80和T100组的培养液氨氮(NH3-N)浓度显著高于其他各组(P<0.05);6)T60组的多项组合效应(MFAEI)要高于其他各组.综上所述,桑叶与羊草的组合能够改善体外瘤胃发酵特性,即存在正组合效应,其中桑叶与羊草的最佳比例为60:40.%This experiment aimed to use in vitro ruminal fermentation method to investigate the associative effects of different combinations of mulberry leaves ( ML) and Leymus chinensis ( LC) , and screened the opti-mum combination ratios of ML and LC. ML and LC were mixed at the ratios of 0:100 ( T0 group) , 20:80 ( T20 group) , 40:60 ( T40 group) , 60:40 ( T60 group) , 80:20 ( T80 group) and 100:0 ( T100 group) , re-spectively. The mixtures were used as the fermentation substrate and incubated in vitro for 72 h for an in vitro fermentation gas production test and a batched in vitro fermentation test. The results showed as follows:1) the-ological maximum gas production, accumulated gas production, microbial protein ( MCP ) concentration in culture fluid and in vitro digestibility of organic matter ( IVDOM ) had increasing trends with the increase of ML ratio in substrate;2) at 72 h, theological maximum gas production, accumulated gas production and IV-DOM in T100 group were significantly higher than those in other groups ( P<0.05) , and MCP concentration in culture fluid in T60 and T100 groups was significantly higher than those in other groups ( P<0.05);3) at 48 and 72 h, culture fluid pH in T60, T80 and T100 groups was significantly lower than that in other groups ( P<0.05);4) at 72 h, total volatile fatty acid ( TVFA) and acetate concentrations in culture fluid in T60, T80 and T100 groups had no significant differences ( P>0.05) , but they were all significantly higher than those in other groups ( P<0.05); 5) at 6, 12 and 72 h, the concentration of ammonia nitrogen ( NH3-N) in culture fluid in T60, T80 and T100 groups was significantly higher than that in other groups ( P<0.05);6) the multi-ply factor associative effect index ( MFAEI) in T60 group was higher than that in other groups. In conclusion, the combination of ML and LC can improve in vitro fermentation characteristics, they have associative effect, and their optimum combination ratio is 60:40.