尿素饲料添加脲酶抑制剂对山羊瘤胃内pH值及氨氮含量影响的研究

本试验使用四头装置永久性瘤胃瘘管的本地成年山羊,分基础对照期,尿素对照期和脲酶抑制剂——尿素期,三期精料补充料的总能量、总氮量相同,尿素期和脲酶抑制剂——尿素期用尿素氮取代基础对照期精料补充料中总氮量的47％,在相同的饲养管理条件下对瘤胃内pH值、NH_3—N进行测定。结果表明:所选用的脲酶抑制剂在一定水平能达到抑制NH_3—N释放速率的效果(占尿素量6％以上)。其抑制作用在一定范围内随脲酶抑制剂用量的加大而增大 脲酶抑制剂的用量为尿素量的5％、6％、7％时,对喂后1小时NH_3—N的抑制百分率分别为10.78％、23.98％、27.29％。

STUDYING IN VIVO THE EFFECT OF UREA WITH UREASE INHIBITOR ON RUMINAL pH VALUE AND AMMONIA NITROGEN IN GOATS

Four mature native goats with permanent ruminal cannulae were used to investigate the effect of urease inhibitor on ruminal pH value and ammonia nitrogen concentration. The experiment included a basic contorl perild,a urea control period and a urease inhibitor-urea period. The goats were supplied with isocaloric and isonitrogenous concentrate supplements, during the three periods. Fourty-seven percent of total nitrogen in concentrate supplement supplied in the basic control period were replaced with urea nitrogen in the urea contorl period and urease inhibitor-urea period. The results indicated that the selected urease inhibitor could effectively restrain the release of ammonia nitrogen when added at a level higher than 6% of that of urea in the concentrate supplement. One hour after feeding,ruminal ammonia nitrogen concentration decreased by 10. 78%.23. 79%,respectively,when the selected urease inhibitor was added at the level reaching 5%. 6% and 7% of the amount of urea in the concentrate supplement.