饲粮不同NFC/NDF对奶山羊瘤胃溶纤维丁酸弧菌、牛链球菌及埃氏巨型球菌含量变化的影响

Effect of Different Dietary NFC/NDF on Populations of B. fibrisolvens,S. bovis and M. elsdenii in Rumen of Dairy Goats

本试验旨在探讨在饲粮不同非纤维性碳水化合物/中性洗涤纤维(NFC/NDF)条件下,奶山羊发生亚急性瘤胃酸中毒(subacute rumen acidosis,SARA)过程中瘤胃溶纤维丁酸弧菌、牛链球菌及埃氏巨型球菌数量的变化。选用6只安装有永久性瘤胃瘘管的泌乳期关中奶山羊为试验动物,采用动物自身前后对照法,试验分4期进行,每期10 d,依次饲喂NFC/NDF比分别为1.02(Ⅰ期)、1.24(Ⅱ期)、1.63(Ⅲ期)、2.58(Ⅳ期)的4种饲粮,以逐渐增加饲粮精料含量的方式诱导奶山羊发生SARA,并采用实时定量PCR技术对瘤胃内溶纤维丁酸弧菌、牛链球菌及埃氏巨型球菌的数量变化进行定量分析。结果表明:1)随着饲粮NFC/NDF比的逐步升高,溶纤维丁酸弧菌和埃氏巨型球菌的数量均增加,但当饲粮NFC/NDF比升至2.58时,与其他试验期相比,埃氏巨型球菌的数量极显著增加(P<0.01),而溶纤维丁酸弧菌的数量却菜显著降低(P<0.01)。2)牛链球菌的数量随着饲粮NFC/NDF比的逐步增加呈显著下降(P<0.05),但到Ⅳ期又恢复到Ⅰ期数量。结果提示,当奶山羊发生SARA时,瘤胃牛链球菌的数量无明显变化,对低pH敏感的溶纤维丁酸弧菌数量急剧下降,而耐酸性的埃氏巨型球菌数量表现为大幅增加。

The objective of this experiment was to investigate the effect of increasing dietary NFC/NDF on populations of B.fibrisolvens,S.bovis and M.elsdenii in the rumen of dairy goats induced subacute rumen acidosis（SARA）.Six lactating Guanzhong dairy goats fitted with permanent rumen fistulae were used in an auto case-control design.This experiment consisted of four experimental periods,with ten days in each period.Goats were fed 4 diets with different NFC/NDF（1.02,1.24,1.63 and 2.58,respectively）.The induction of SARA was conducted by gradually increasing dietary NFC/NDF.Real-time PCR was used to detect the populations of B.fibrisolvens,S.bovis and M.elsdenii.The results showed as follows：1） the number of B.fibrisolvens and M.elsdenii was both increased with the gradual increasing of dietary NFC/NDF,and when NFC/NDF reached the level of 2.58,the number of M.elsdenii was significantly increased（P〈0.01）,whereas the number of B.fibrisolvens was significantly decreased（P〈0.01）.2） The number of S.bovis was significantly decreased with the gradual increasing of dietary NFC/NDF（P〈0.05）,however,during SARA occurrence period,the number of S.bovis returned to the level in the experimental initial stage.The results indicated that there was no difference in the number of S.bovis at the induced stage of SARA,however,the number of B.fibrisolvens was sharply decreased,whereas the number of M.elsdenii which is a kind of aciduric bacteria was significantly increased.