鸡对饲料氨基酸有效利用率的研究

Effective availability of amino acids in feedstuffs of cockerels

采用Sibbald“真代谢能”法测定饲料原料的氨基酸有效利用率。试验鸡分别强饲玉米、大豆粕和鱼粉 ,测定鸡强饲后的氨基酸排出量。结果表明 ,不同种类饲料原料的氨基酸利用率存在差异 ,玉米与大豆粕、鱼粉间差异显著 (P <0 0 5)。不同种类氨基酸之间利用率也有差异。 3种饲料原料的氨基酸真利用率均大于表观利用率 ,其中玉米的差异达到极显著水平 (P <0 0 1 ) ,表明内源性氨基酸对氨基酸利用率有影响 ,且这种影响随饲料原料中粗蛋白质水平的下降而增大。 3种饲料原料的氨基酸利用率在去盲肠鸡与正常鸡之间存在差异。盲肠微生物对饲料原料的氨基酸利用率有影响 ,且对不同种类氨基酸的影响有差异 ,这种影响不能通过内源性氨基酸的校正而消除。另外 ,内源性氨基酸的排泄量在去盲肠鸡大于正常鸡。

The effective availability of amino acids in the feedstuffs were determined by Sibbald'TME'method.The results showed that different kinds of feedstuffs had different amino acids availability.The average apparent availability of amino acids in corn grain was significantly lower than that in soybean meal(sol.)and fishmeal(P<0 05).There were also differences among different kinds of amino acids.The true amino acid availabilities were higher than apparent amino acid availabilities in three feedstuffs,but with the significant differences only in corn grain(P<0 01).The endogenous amino acids had increasing effects on amino acids availability as crude protein content of feedstuffs declined.The availability of amino acids in three feedstuffs was different between the caecectomized and intact cockerels indicating that microbe in caecum had effects on amino acid availability,which could not eliminated by removing endogenous amino acids.The excretion of endogenous amino acids from caecectomized cockerels was more than that from intact cocker,showing endogenous amino acids being affected by microbe in caecum.