蛋白肽对生长猪生长性能、养分表观消化率的影响

试验旨在探讨日粮中添加不同体外胃蛋白酶消化率的蛋白肽（A80、A90）对生长猪生长性能及养分表观消化率的影响。采用单因子随机设计，试验1：选取300头杜洛克猪×长白猪×大白猪三元生长猪，随机分为5组，每组4个重复，每个重复15头。Ⅰ组饲喂基础日粮，Ⅱ~Ⅴ组分别在基础日粮中添加1%、2%、3%、4% A80，试验期30 d。试验2：选取240头杜洛克猪×长白猪×大白猪三元生长猪，随机分为4组，每个组4个重复，每个重复15头。Ⅰ组饲喂基础日粮，Ⅱ~Ⅳ组分别在基础日粮中添加1%、2%、3% A90，试验期30 d。结果显示，试验1：各组间平均日增重、平均日采食量及料重比均无差异显著（P>0.05），但随A80添加量的增加平均日增重有降低的趋势；Ⅱ组干物质、粗蛋白质表观消化率显著高于Ⅰ、Ⅲ、Ⅴ组（P<0.05），但与Ⅳ组差异不显著（P>0.05），随着A80添加量的增多，钙、磷表观消化率有所提高，但没有规律性。试验2：随着日粮中A90添加量的增加，平均日增重先增加后降低。Ⅲ组平均日增重显著高于Ⅰ组（P<0.05），与其他组间差异不显著（P>0.05），Ⅲ组平均日采食量显著高于其他组（P<0.05）。干物质、粗蛋白质表观消化率随着A90添加量的增加有下降的趋势。综上所述，在生长猪日粮中添加A80蛋白肽对生长性能没有改善作用，营养物质消化率均先增高后降低；随着A90蛋白肽添加量的增多，生长猪的生长性能呈二次性提高，最适宜剂量为2%~3%。

Effects of Adding Protein Peptide to Diets on Growth Performance and Nutrient Apparent Digestibility of Growing Pigs

The experiment was aimed to study the effects of protein peptide with different pepsin digestibility in vitro (A80,A90) on growth performance,nutrient apparent digestibility of growing pigs. Experiment 1:300 growing pigs of Duroc pig×Landrace pig×Yorkshire pig were selected and randomly divided into 5 groups with 4 repeats pre group and 15 pigs per repeat. The pig of group Ⅰ was fed with basal diet,that of groups Ⅱ to Ⅴ were fed with basal diet with 1%,2%,3%,4% A80 supplement,respectively. The experiment period lasted for 30 d. Experiment 2:240 growing pigs of Duroc pig×Landrace pig×Yorkshire pig were selected and randomly divided into 4 groups with 4 repeats pre group and 15 pigs per repeat. The pig of group Ⅰ was fed with basal diet,that of groups Ⅱ to Ⅳ were fed with basal diet with 1%,2%,3% A90 supplement,respectively. The experiment period lasted for 30 d. The results showed that the average daily gain (ADG),average daily feed intake (ADFI) and feed/gain (F/G) had no significant difference among all groups (P>0.05) in experiment 1. But the ADG had a tendency to reduce with the increase of A80. The DM,CP apparent digestibility of group Ⅱ was significant higher than that of groups Ⅰ,Ⅲ and Ⅴ (P<0.05),and had no significant difference with group Ⅳ(P>0.05). Digestibility of Ca and P showed a tendency to improve with the increase of A80,but there was no regularity. Experiment 2:With the increase does of A90,ADG was increased firstly and then decreased. The ADG of group Ⅲ was significantly higher than that of group Ⅰ(P<0.05),and had no significant difference with other groups (P>0.05).The ADFI of group Ⅲ was significantly higher than that of other groups (P<0.05).DM and CP apparent digestibility showed a tendency to decline with the increase dose of A90.In conclusion,A80 had no significant improvement on growth performance and A90 showed a quadratic improvement to pig's growth performance and the best addition percentage of protein hydrolysate in diet was 2% to 3%.