蚕沙替代精料对黑山羊瘤胃细菌数量及多样性的影响

Effect of silkworm feces on the quantity and diversity of rumen bacteria of goats

旨在研究蚕沙替代精料对黑山羊瘤胃细菌多样性及瘤胃产甲烷杆菌、产琥珀酸杆菌和黄色瘤胃球菌数量的影响.试验选用35只体重相近(20±1.3 kg)且健康的3月龄乐至黑山羊阉公羊,随机分为5个处理组,每组7只山羊,单栏单饲,对照组饲喂基础精料,试验组(Ⅰ、Ⅱ、Ⅲ和Ⅳ组)分别以25%、50%、75%、100%蚕沙替代基础精料,粗料各组相同,预试期20 d,试验期90 d.试验结束时每个处理组选择4头接近组内平均体重的羔羊屠宰取瘤胃液用于检测瘤胃微生物;采用Real Time-PCR法检测产甲烷杆菌、产琥珀酸杆菌和黄色瘤胃球菌的数量,采用PCR/DGGE法检测瘤胃细菌的多样性.结果表明:(1)蚕沙替代不同水平精料影响瘤胃产甲烷杆菌、产琥珀酸杆菌和黄色瘤胃球菌数量,其中随着蚕沙替代水平增加,产甲烷杆菌有减少趋势,而产琥珀酸杆菌有先减少后增加趋势,黄色瘤胃球菌先增加,而后降低再增加;(2)蚕沙替代不同水平精料影响瘤胃细菌多样性,其中随着蚕沙替代水平增加,瘤胃细菌多样性有减少趋势,若继续增加,几乎无变化.综上,蚕沙替代精料影响黑山羊瘤胃细菌数量和多样性,其中产甲烷杆菌、产琥珀酸杆菌和黄色瘤胃球菌数量变化趋势不尽相同,而细菌多样性有减少趋势.

To determine the effect of silkworm feces as a replacement for concentrate on Methanogen, Fibrobacter succinogenens and Ruminococcus flavefaciens quantity and bacterial diversity in rumen of goats, thirty-five three-month-old goats （ BW = 20 ±1.3kg） were randomly divided into 5 groups of 7 each. The control group was fed on basal concentrate,while treatment I , II, m and IV group were fed on diets added 25% ,50% ,75% and 100% silkworm feces,respectively. The quantity of rumen Meth- anogen, Fibrobacter succinogenens and Ruminococcus flavefaciens was measured by quantitative Real Time-PCR;the diversity of the rumen bacteria population was investigated using denaturing gradient gel electrophoresis（DGGE）. Silkworm feces replacing concentrate affected rumen Methanogen, Fibrobacter succinogenens and Ruminococcus flavefaciens quantity. The quantity of Meth- anogen and Fibrobacter succinogenens decreased with the increase of replace level, and then the quantity of Fibrobacter succino- genens increased. The quantity of Ruminococcus flavefaciens increased first, then decreased, and increased again. The diversity of the rumen bacteria population was affected by silkworm feces, which decreased with increasing replacement level, but not at higher replacement levels. Silkworm feces replacing concentrate affected rumen Methanogen, Fibrobacter succinogenens and Ru- minococcus flavefaciens quantity and the diversity of the rumen bacteria. Silkworm feces replacing concentrate was found to alter the quantity of these bacteria wih different degrees, but reduced the diversity of the rumen bacteria population.