低蛋白质、无微量元素添加日粮对育肥猪生产性能、氮利用及胴体性能的影响

Effects of diets with low protein and no trace elements adding on production performance,nitrogen utilization and carcass performances of fattening pigs

试验选取平均初始体重(85.00±2.00)kg的杜×长×大育肥猪120头,随机分为3个组,每组5个重复,每个重复8头猪,预饲期5 d,试验期31 d。试验1组为基础日粮组(粗蛋白质质量分数为13.96%)、试验2组为低蛋白质-氨基酸平衡日粮组(粗蛋白质质量分数为9.87%)、试验3组为低蛋白质-氨基酸平衡、无微量元素添加日粮组(粗蛋白质质量分数为9.87%+不添加微量元素的预混料)。结果显示,与基础日粮组相比,试验2组和试验3组的平均日采食量、平均日增重有下降趋势(P>0.05),耗料增重比升高(P>0.05);试验2组和试验3组的摄入氮含量分别低于试验1组31.96%和30.84%(P<0.05);各组粪氮百分含量无显著变化(P>0.05);试验2组和试验3组的尿氮浓度分别低于试验1组23.93%和15.64%(P<0.05);与试验1组相比,试验2组和试验3组的胴体重和背膘厚度有升高趋势(P>0.05)、眼肌面积及屠宰率均无显著变化;所有组的肉品质性状均无显著差异。研究表明,基础日粮粗蛋白质水平降低4个百分点,微量元素降低14%~60%后,育肥猪的生长性能、胴体性能及肉品质性状均无显著变化,但是均能够显著降低氮摄入量和氮排放量。

This study was conducted to investigate the effects of dietary crude protein level,amino acid balance and no trace elements adding on growth performance,nitrogen emission level,carcass performance and meat quality of finishing pigs.A total of 120 Durco×Landrace×Large White pigs with average original weight of(85.0±2.0)kg were selected and randomly divided into 3 groups with 5 replicates per group and each replicate had 8 pigs.The three groups were as follows:test 1 group was routine diet with 13.96%crude protein in diet,test 2 group was low protein amino acid balance diet with 9.87%crude protein in diet,test 3 group was low protein amino acid balance and no trace elements added with 9.87%crude protein in diet.The results showed that,compared with the routine diet group,the ADFI and ADG of test 2 and 3 groups were showed a downward trend(P>0.05),and the ratio of feed to weight gain increased(P>0.05).The content of nitrogen intake in group 2 and group 3 was significantly lower than that in group 1(31.96%and 30.84%,respectively)(P<0.05);there was no significant change in fecal nitrogen content in each group(P>0.05);urinary nitrogen concentration in group 2 and group 3 was significantly lower than that in test 1 group 23.93%and 15.64%(P<0.05),respectively.Compared with test 1 group,the carcass weight and back fat thickness of test 2 and 3 groups were increased(P>0.05);There were no significant changes in eye muscle area,slaughter rate and meat quality traits in test 1,2 and 3 groups.In conclusion,there were no significant changes in growth performance,carcass performance and meat quality of finishing pigs after the crude protein content of basal diet was reduced by 4 percentage points and trace elements content decreased by 14%to 60%,but both the nitrogen intake and nitrogen emissions amount were significantly reduced.