外源酶及其添加时间对鸡饲粮氨基酸消化率影响的研究

30只18周龄的伊莎褐种公鸡随机分为6组,每组5只。一组用于内源氨基酸校正的样品采集。其它5组作强饲试验,其中一组采用常规日粮预试一周并强饲常规日粮;另外四组饲喂加酶日粮,预试期分别为一周、二周、三周及四周,再强饲加酶日粮,氨基酸消化率采用“TME”法测定。结果表明:(1)酶及不同的预试期可使17种氨基酸的表观消化率有不同程度的提高,但提高幅度因不同氨基酸而异。采用加酶日粮预试并强饲可减少氨基酸消化率的变异范围和标准差。(2)与常规日粮组相比,加酶日粮预试一周、二周、三周及四周再强饲,可使总氨基酸表观消化率分别提高3.85、3.49、2.76及4.12个百分点。以预试四周为佳。(3)Sibbald's“TME”法测定鸡加酶饲粮氨基酸消化率时,采用加酶日粮预试一周后强饲为宜。

Influence of Exogenous Enzymes and Its Supplemental Time on Amino Acid Digestibility of Poutry Ration

Thirty eighteen-weeks-old ISA Brown cockerels were randomly assigned to six groups with five birds per group.One group birds were used as blank experiment to determine endogenous amino acid excremental amount.The other five groups were used for forced-feeding experiment.Birds of one group were fed by diet without enzyme for one week,then amino acid digestibility(AAD) of diet was measured by Sibbald's "TME" method.The birds of other four groups were fed by diets with enzyme for one week,two weeks,three weeks or four weeks then AAD was determined.The results showed:(1)Apparent digestibility of seventeen amino acid were increased in different amount for different amino acid by exogenous enzyme and various pre-experimental period.The variation and standard deviation of AAD were reduced by pre-trial with diet of enzyme supplementation.(2)Total AAAD(apparent amino acid digestibillity) were increased by 3.85%,3.49%,2.76% and 4.12% when cockerels were fed pre-experimental diet with enzyme supplementation for one week,two weeks,three weeks,and four weeks compared with common diet group.AAAD of diet with enzyme for four weeks was the highest,and then followed by of the one-week,two weeks and three weeks.(3) The results suggested that the time of feeding cockerels pre-experimental diets with enzyme is one week when AAD of diet with enzyme is determined by Sibbald's "TME" method.