饲粮中燕麦干草含量对绵羊瘤胃液pH及微生物区系的影响

本试验旨在研究饲粮燕麦干草含量对绵羊瘤胃液p H及微生物区系的影响。选取9只体况和体重(70.32±2.14)kg]相近、装有永久性瘘管的德国美利奴与蒙古羊杂种公羊,采用3×3拉丁方设计,随机分为3组,每组3只,各组分别采用全株玉米青贮、全株玉米青贮+燕麦干草(1∶1)(混合组)、燕麦干草为粗饲料。饲粮精粗比34.50∶65.50。进行3期饲养试验,每期20 d,15 d预试期,5 d采样期。采集饲喂前(0 h)和饲喂后1、3、5和7 h的瘤胃液,测定p H,采用实时定量PCR方法测定微生物相对含量。结果表明:1)全株玉米青贮组的瘤胃液p H在1、5 h均显著低于燕麦干草组(P0.05),在3 h极显著低于混合组(P0.01);2)混合组和燕麦干草组瘤胃液真菌的相对含量在0 h均极显著高于全株玉米青贮组(P0.01),燕麦干草组在5 h真菌相对含量显著高于全株玉米青贮组(P0.05);3)混合组原虫的相对含量在1、5 h显著低于全株玉米青贮组(P0.05);4)饲喂后5 h,混合组和燕麦干草组的纤维分解菌相对含量均较高,其中燕麦干草组黄色瘤胃球菌相对含量显著高于全株玉米青贮组(P0.05),白色瘤胃球菌和产琥珀酸丝状杆菌的相对含量极显著高于全株玉米青贮组(P0.01)。综上所述,在精粗比为34.50∶65.50的饲粮中采用全株玉米青贮+燕麦干草(1∶1)的粗饲料,有利于维持绵羊瘤胃内环境的稳态及瘤胃微生物的生长,白色瘤胃球菌和产琥珀酸丝状杆菌为优势菌。

Effects of Dried Oat Hay Content in Diet on Rumen Fluid pH and Microflora of Sheep

In order to investigate the effects of dried oat hay content in diet on rumen fluid pH and microflora of sheep. Nine German merino sheep×Ongolian sheep cross breed rams with similar body condition and body weight (70.32±2.14) kg] were used in a replicated 3×3 Latin square design, and randomly divided into 3 groups with 3 rams per group. Sheep were fed whole corn silage, whole corn silage+dried oat hay ( 1∶1 ) ( mixed group) and dried oat hay as roughages, and the dietary concentrate to roughage ratio was 34.50∶65.50. The experimental consisted of 3 periods with 20 d per period, and each period had 15 d for pre?test and 5 d for sampling. Rumen fluid was collected before feeding (0 h) and 1, 3, 5 and 7 h after feeding to measure pH, meanwhile, the relative contents of microorganisms with real?time quantitative PCR method. The results showed as follows:1) ruminal pH of whole corn silage group was significantly lower than that of dried oat hay group at 1 and 5 h (P<0.05), extremely significantly lower than that of mixed group at 3 h (P<0.01); 2) the relative content of fungus in rumen fluid of mixed group and dried oat hay group was extremely significantly greater than that of whole corn silage at 0 h ( P<0.01) , and dried oat hay group was also significantly higher than whole corn silage group ( P<0.05);3) the relative content of protozoa in rumen fluid of mixed group was significantly lower than that of whole corn silage group at 1 and 5 h ( P<0.05); 4) after 5 h of feeding, the relative contents of cellulolytic bacteria of mixed group and dried oat hay group were relatively high, among which the relative content of Ruminococcus flavefaciens was significantly higher than that of whole corn silage group (P<0.05), the relative contents of Ruminococcus albus and Fibrobacter succinogenes were extremely significantly higher than those of whole corn silage group ( P<0.01) . In conclusion, it is benefit for maintain stable ecosystem of rumen and growth of microorganisms that using whole corn silage+dried oat hay (1∶1) as roughage in diet with concentrate to roughage ratio of 34.50∶65.50, and Ruminococcus albus and Fibrobacter succinogenes are dominant bacteria.