基于瘤胃模拟技术的马铃薯茎叶混合青贮斗体外瘤胃发酵特性研究

摘要

本试验采用瘤胃模拟技术(Rusitec)研究了马铃薯茎叶混合青贮料饲粮体外瘤胃发酵特性.采用单因素完全随机设计,将Rusitec系统的8个发酵罐分为2组,分别采用玉米秸青贮料、马铃薯茎叶混合青贮料(马铃薯茎叶与玉米秸按40:60混合青贮)配制发酵绵羊饲粮,2组分别以此为发酵底物,每组4个重复,每个重复1个发酵罐.试验包括8d的预试期和2d的采样期.结果表明:马铃薯茎叶混合青贮料组的产气量,全期发酵液总氮、氨氮(除了换料后3h)和微生物氮含量,换料后6、9h的发酵液丙酸含量均显著高于玉米秸青贮料组(P＜0.05),甲烷产量、换料后3h的发酵液pH、换料后9h的发酵液乙酸含量、换料后6和9h的发酵液乙酸/丙酸显著低于玉米秸青贮料组(P＜0.05).2组的营养物质降解率和其他瘤胃发酵指标无显著差异(P＞0.05).由此可以看出,马铃薯茎叶混合青贮料对绵羊瘤胃体外发酵没有产生不良影响,且有利于减少瘤胃甲烷对环境的污染,同时还促进了反刍动物对能量和氮的利用.%This study was conducted to investigate the in vitro rumen fermentation characteristics of potato vines and leaves mixed silage using rumen simulation technique (Rusitec).A complete one-factor randomized design was used.Eight fermentation tanks of Rusitec system were divided into two groups with 4 replicates per group and 1 tank per replicate.Corn stalk silage and potato vines and leaves mixed silage [potato vines and leaves and corn stalk (40∶60) were mixed for silage] were used to prepare diets for sheep,respectively,and the two groups used the diets as fermentation substrates,respectively.The study consisted of an 8 d pre-test period and a 2 d sampling period.The results showed as follows:compared with corn stalk silage group,potato vines and leaves mixed silage group had significantly higher gas production,contents of total nitrogen,ammonia nitrogen (except 3 h after substrate replacement) and microbial nitrogen in fermentation fluid for whole period,and propionic acid content in fermentation fluid at 6 and 9 h after substrate replacement (P＜0.05),and had significantly lower methane production,fermentation fluid pH at 3 h after substrate replacement,acetic acid content in fermentation fluid at 9 h after substrate replacement,and acetic acid/propionic acid in fermentation fluid at 6 and 9 h after substrate replacement (P＜0.05).There were no significant effects on nutrients degradation rate and other rumen fermentation parameters (P＞0.05).These results indicate that potato vines and leaves mixed silage has no negative effects on in vitro rumen fermentation,can reduce methane pollution,and promote the utilization of energy and nitrogen in ruminants.