不同品质粗饲料日粮及添加酵母培养物对绵羊瘤胃内主要纤维素酶及纤维物质降解的影响

Effect of Roughage Quality and Adding Yeast Culture on Activities of Main Cellulases and Fiber Digestion in Rumen of Sheep

研究不同品质粗饲料混合日粮及添加酵母培养物对瘤胃内几种主要纤维素酶酶活及纤维物质降解的影响。试验将带有永久瘤胃瘘管的9只绵羊随机分成3组,以粗饲料分级指数GI为指标对粗饲料品质进行划分,在精粗比为2:8条件下配制3种混合日粮,形成含高GI粗饲料日粮组(H组,粗料GI值=2.89)、含中GI粗饲料日粮组(M组,粗料GI值=1.73)和含低GI粗饲料日粮组(L组,粗料GI值=0.65)。利用DNS法研究瘤胃内几种主要纤维素酶酶活的变化以及对纤维物质降解的影响。试验结果表明:3个试验组木聚糖酶的活性在饲后2h内下降,以后逐渐升高,到8h时达到最高并保持平稳;滤纸酶活和果胶酶活与粗饲料品质之间没有明显的规律性;添加酵母培养物(YC)后能够增加木聚糖酶活和果胶酶活,而M组和L组滤纸酶活有减少的趋势,但差异均不显著(P>0.05)。由本研究可知:3个试验组随着粗饲料品质的升高,木聚糖酶活有增加的趋势;果胶酶活和滤纸酶活未表现出一定的规律性。添加酵母培养物后有提高木聚糖酶活和果胶酶活的趋势,3个试验组的DM、NDF、ADF有效降解率都有不同程度的增加。

To studies the effect of different daily roughage quality and adding yeast culture on activities of main celluloses and fiber digestion in the tureen of sheep. Nine sheep with permanent cannular were randomly divided into three groups, and the roughage quality was evaluated by Grading Index （GI） of roughage. Three kinds of roughages were used in the trial diets which had the same ratio of roughage to concentrate （R/C） of 8 ： 2 to adjust the different roughage qualities. Three qualities of diets included higher quality roughage （GI = 2.89 MJ）, middle quality roughage （GI = 1.73 MJ） and lower quality roughage （GI = 0.65 MJ）, respectively. The method of DNS was utilized to study the changes in activities of 3 main fiber hydrolytic enzymes and fiber digestion. The results showed that The activities of xylanase were all decresed in 2 hours after feeding, but gradually increased later, and reached the highest value at 8 h, then being stable at this level; The activities of filter paper enzyme and pectinase had no obvious correlation with GI; Adding yeast culture increased the activities of xylanase and pectinase, while YC tended to decrease the activity of filter paper enzyme in M group and L group, but the differences were not significant （P〉0.05）. Activity of xylanase tended to increase with the increase of GI; The activities of filter paper enzyme and pectinase had no correlation. After adding yeast culture, the avtivities of xylanase and pectinase had an increasing tendency, also the DM.ADF.NDF of 3 groups were all increased to different extents.