^(15)N尿素在兔体内消化吸收及利用机理研究.禁食粪兔对日粮尿素的利用  

Studies on the Mechanism of Absorption,Digestion and Utilization of ^(15)N urea in Rabbits Ⅲ.Utilization of Urea in Diet for Coprophagy prevented Rabbit

作　　者：周维仁[1] 高家骅[1] 章云[1] 于亚君[1] 陈明[1] 

机构地区：[1]江苏省农业科学院饲料食品研究所,南京210014

出　　处：《江苏农业学报》1999年第3期177-181,共5页Jiangsu Journal of Agricultural Sciences

基　　金：国家自然科学基金

摘　　要：应用稳定同位素１ ５ Ｎ 尿素示踪技术，经套颈圈禁食粪兔对日粮尿素的消化代谢试验表明：兔在禁食粪的条件下，尿素氮平衡值陡降至３８１±１３ ｍ ｇ／ｄ，利用系数锐减为８０％ ±０４％ ，严重地抑制了兔对日粮中尿素的利用；软粪中存留标记氮在兔利用日粮尿素中占有一定的地位，其中，微生物群随着食粪过程进入胃肠道中，将尿素和氨直接转化成菌体蛋白，从而增强了人们对兔利用尿素氮的机理与途径的认识。Six 2 5 kg New Zealand male rabbits were selected to study the metabolism of urea N being utilized in rabbit using 15 N urea tracing technique.In order to prevent coprophagy,each rabbit had a collar in its neck.Basal diet which contained 16 01% of crude protein was fed to the rabbits for 120 g/d with additive 1% of 15 N urea(1 2 g).Results were showed as follows:① 15 N balance value in coprophagy prevented rabbits was 38 1±1 3 mg/d, 7 0%±0 3% to the 15 N urea uptake content,and utilization coefficient of 15 N was 8 0%±0 4%,about 39% to that of the normal rabbits.It could be seen that prevented corprophagy inhibited the utilization of 15 N in the diet.②Protein nitrogen in stomach and intestine of coprophagy prevented rabbits were 9 8% and 14 7%,14% and 23% to those of the normal rabbits,respectively.It could be inferred that microbiota in the normal rabbits played an important role on the transformation of 15 N urea to protein nitrogen.From study Ⅰ,Ⅱand Ⅲ it could be elucidated that:①rabbits could utilize urea in their diets;②strong caecum and coprophagy was the special physiological base for the utilization of urea;③microbiota was the key in use of non peotein nitrogen

关 键 词：兔 禁食粪 日粮 尿素利用 同位素示踪 

分 类 号：S829.1[农业科学—畜牧学] S816.79[农业科学—畜牧兽医]