低蛋白饲粮补充不同氨基酸对育肥猪生长性能、血清生化指标、养分表观消化率及氮排放的影响

Effects of low protein diets supplemented with different amino acids on growth performance,serum biochemical indices,nutrient apparent digestibility,and nitrogen emission of finishing pigs

试验旨在研究低蛋白饲粮补充不同氨基酸对育肥猪生长性能、血清生化指标、养分表观消化率及氮排放的影响。选取体重约75 kg“杜×长×大”育肥猪120头,随机分为3个处理,每个处理设4个重复,每个重复10头猪。对照组饲喂粗蛋白(CP)水平为13.45%的饲粮,试验Ⅰ组和Ⅱ组饲粮CP水平为10.41%,试验Ⅰ组补充赖氨酸、蛋氨酸、色氨酸、苏氨酸4种氨基酸,试验Ⅱ组补充赖氨酸、蛋氨酸、色氨酸、苏氨酸、缬氨酸、异亮氨酸6种氨基酸。试验期28 d。结果表明:与对照组相比,试验Ⅰ组平均日采食量和平均日增重显著降低(P<0.05),试验Ⅱ组平均日采食量和平均日增重低于对照组(P>0.05);试验Ⅰ组和Ⅱ组血清尿素氮含量显著降低(P<0.05);各组养分表观消化率均无显著差异(P>0.05);试验Ⅰ组和Ⅱ组食入氮、尿氮排放、总氮排放显著降低(P<0.05),试验Ⅰ组和Ⅱ组粪氮排放降低,氮沉积率和氮表观生物学价值升高(P>0.05)。研究表明,低蛋白饲粮(CP=10.41%)补充6种氨基酸对育肥猪生长性能无负面影响,且可以有效降低氮排放。

This experiment was conducted to investigate the effects of low protein diet supplemented with different amino acids on the growth performance,serum biochemical indices,nutrient apparent digestibility,and nitrogen emission of finishing pigs.A total of 120'Duroc×Landrace×Yorkshire'finishing pigs with a body weight of about 75 kg were randomly divided into three treatments with four replicates per treatment and 10 pigs per replicate.The pigs in control group were fed a diet with 13.45%CP level,and the pigs in trial groupⅠand groupⅡwere fed a diet with 10.41%CP level.The pigs in trial groupⅠwere fed four amino acids(lysine,methionine,tryptophan,and threonine),and the pigss in trial groupⅡwere fed six amino acids(lysine,methionine,tryptophan,threonine,valine,and isoleucine).The experiment lasted for 28 days.The results showed that compared with the control group,the average daily feed intake and average daily gain in trial groupⅠwere significantly decreased(P<0.05),while the daily feed intake and daily gain in trial groupⅡwere lower than those in control group(P>0.05).The content of serum urea nitrogen in experimental groupⅠand groupⅡwas significantly decreased(P<0.05).There were no significant differences in the apparent digestibility of nutrients in all groups(P>0.05).Nitrogen intake,urinary nitrogen emission and total nitrogen emission in trial groupⅠand groupⅡwere significantly decreased(P<0.05),the fecal nitrogen emission was decreased,nitrogen deposition rate and nitrogen apparent biological value were increased in trial groupⅠand groupⅡ(P>0.05).The study indicates that a low protein diet(CP=10.41%)supplemented with six kinds of amino acids has no negative effect on growth performance of finishing pigs,and can effectively reduce nitrogen emissions.