【摘要】 本试验旨在探究酵母水解物对湖羊体外瘤胃发酵特性和饲料营养瘤胃有效降解率的影响。体外试验中，在培养底物中添加0（对照组）、1%的酵母水解物（HY组），在体外模拟瘤胃发酵培养48 h后，测定产气量和瘤胃发酵特性参数。原位尼龙袋降解试验中，选取3只装有永久瘘管的成年湖羊（♂），用尼龙袋法测定两个处理组的饲料干物质（DM组）和粗蛋白质（CP）在瘤胃的动态降解率与降解参数。体外试验结果表明：体外发酵前6 h，各处理组累计产气量差异不显著（P> 0.05），但随着发酵时间延长至9 h之后，HY组累积产气量显著提升，其中48 h总产气量提升6.88%(P <0.05);HY组瘤胃液pH显著提高，总挥发酸浓度提升11.1%，丙酸浓度提升20.6%，乙丙比降低11.8%(P <0.05)，但对体外发酵干物质消化率、乙酸浓度和瘤胃微生物蛋白含量无显著影响（P> 0.05）。原位尼龙袋试验结果表明：与对照组相比，HY组4 h的干物质瘤胃实时降解率显著提升6.86%(P <0.05)，干物质瘤胃有效降解参数a、a+b和ED值分别显著提高16.5%、13.4%和5.8%(P <0.05)；与对照组相比，HY组在2、4、8 h和12 h的粗蛋白质实时降解率分别显著提高16.8%、9.7%、8.6%和8.0%(P <0.05)，粗蛋白质瘤胃有效降解参数a值和ED值分别显著提高21.1%和8.2%(P <0.05),b值有提高的趋势，提升20.1%(P=0.087);c值显著降低（P <0.05）;0点值是否参与曲线拟合对各参数无显著影响。综上，日粮添加酵母水解物对氮源利用效率无显著影响，但可显著提升体外瘤胃发酵产气量、总挥发性脂肪酸、丙酸及丁酸浓度，显著降低乙丙比，改善瘤胃发酵特性，并维持瘤胃pH稳定和瘤胃健康状态；另外，酵母水解物可显著提升日粮干物质及粗蛋白质的瘤胃实时降解率、有效降解率及各项降解参数。更多还原

【Abstract】 This experiment was designed to investigate the effects of hydrolyzed yeast(HY)on the in vitro rumen fermentation characteristics and effective rumen degradation rate of feed nutrients in Hu sheep. In the in vitro experiment,0(control group)and 1% HY(HY group) were added to the culture substrate,and the gas production and rumen fermentation characteristic parameters were measured after 48 hours of in vitro simulated rumen fermentation. In the in-situ nylon bag degradation test,three adult Hu sheep （ ♂ ）with permanent fistulas were selected,and the nylon bag method was used to measure the dynamic rate and degradation parameters of feed dry matter(DM)and crude protein(CP) in the rumen of the two treatment groups. In vitro test results showed that in the first 6 hours of in vitro fermentation,the cumulative gas production of each treatment group was not significantly different(P > 0.05). However,as the fermentation time was extended to 9 hours,HY significantly increased the cumulative gas production,of which the total gas production in 48 hours increased by 6.88 %(P < 0.05);the pH of rumen fluid in the HY group significantly increased,the total volatile acid concentration increased by 11.1%,the propionic acid concentration increased by 20.6%,and the ethylene-propylene ratio decreased by 11.8%(P < 0.05),However,it had no significant effect on in vitro fermentation dry matter digestibility,acetic acid concentration and rumen microbial protein content(P > 0.05). In situ nylon bag test results showed that compared with the control group,the 4-hour real-time degradation rate of dry matter rumen in the HY group was significantly increased by 6.86%(P <0.05). The effective rumen degradation parameters a,a+b and ED value of the dry matter were significantly higher,respectively. Compared with the control group,the real-time degradation rate of crude protein in the HY group at 2,4,8 h and 12 h significantly increased by 16.8%,9.7%,8.6% and 8.0% respectively(P <0.05). The crude protein rumen effective degradation parameters a value and ED value significantly increased by 21.1% and 8.2% respectively(P < 0.05). The b value showed an increasing trend,increasing by 20.1%(P=0.087). The c value was significantly reduced(P < 0.05);Whether the 0 point value participates in curve fitting had no significant impact on each parameter. In summary,adding hydrolyzed yeast to the diet had no significant effect on nitrogen source utilization efficiency,but it could significantly increase in vitro rumen fermentation gas production,total volatile fatty acids,propionic acid and butyric acid concentrations,significantly reduce the ethylene-propylene ratio,and improve rumen fermentation characteristics,and maintain rumen pH stability and rumen health;Moreover,hydrolyzed yeast significantly improves the rumen real-time degradation rate,effective degradation rate and various degradation parameters of dietary dry matter and crude protein.更多还原