N-酰基高丝氨酸内酯酶在肉鸡中应用的耐受性评价

Evaluation of Tolerance of N-Acyl-Homoserine Lactonase in Broiler Chickens

本试验依据《饲料和饲料添加剂畜禽靶动物耐受性评价试验指南(试行)》对N-酰基高丝氨酸内酯酶(AHLase)在肉鸡中的应用进行耐受性评价。采用双因素试验设计,选取健康、体重接近的1日龄科宝肉仔鸡360只,随机分为3组,每组6个重复,每个重复20只鸡,公母各占1/2且分笼饲养。对照组饲喂基础饲粮,试验组在基础饲粮中分别添加500(AHLase-500)和5000 mg/kg(AHLase-5000)的AHLase。试验期42 d。结果表明:1)与对照组相比,AHLase-5000组公鸡1~21日龄的平均日采食量显著提高(P<0.05),22~42日龄以及1~42日龄的料重比显著降低(P<0.05);AHLase-5000组母鸡22~42日龄末重显著提高(P<0.05),而AHLase-500、AHLase-5000组1~42日龄母鸡的平均日采食量显著降低(P<0.05)。2)试验期内公鸡的平均日增重、平均日采食量显著高于母鸡(P<0.05)。1~21日龄公鸡的料重比有高于母鸡的趋势(P=0.075)。性别对1~21日龄肉鸡末重表现出趋于显著的影响(P=0.079)。3)随着AHLase添加水平的增加,1~21日龄肉鸡的平均日采食量显著提高(P<0.05),平均日增重有提高的趋势(P=0.052),而料重比显著降低(P<0.05);22~42日龄肉鸡的末重显著提高(P<0.05)。4)AHLase添加水平和性别在1~21日龄平均日采食量、22~42日龄平均日采食量以及1~42日龄料重比中均表现出显著互作效应(P<0.05);在22~42日龄料重比(P=0.069)以及1~42日龄平均日增重(P=0.064)中表现出互作趋势。5)饲粮中添加AHLase对肉鸡血常规和血清生化指标无显著影响(P>0.05)。6)饲粮中添加AHLase对肉鸡器官指数无显著影响(P>0.05),组织未观察到形态结构变化。由此可见,饲粮中添加5000 mg/kg的AHLase改善了肉鸡生长性能,对血液生理生化指标和内脏器官发育无显著影响,表明肉鸡对AHLase的耐受剂量在5000 mg/kg以上。

This study aimed to evaluate the tolerance of N-acyl-homoserine lactonase(AHLase)in broilers application,following the Guidelines for Evaluation of Tolerance of Livestock and Poultry Target Animals in Feed and Feed Additives(Trial).A total of 360 one-day-old Kebao broiler chickens,with similar health and weight,were randomly divided into 3 groups.Each group had 6 replicates,with 20 chickens in each replicate.The replicates consisted of 1/2 cocks and 1/2 hens,and the chickens were raised in separate cages.The control group was fed a basic diet,while the experimental groups were supplemented with 500(AHLase-500)and 5000 mg/kg(AHLase-5000)of AHLase in the basic diet,respectively.The experimental period lasted for 42 days.The results showed as follows:1)the average daily feed intake of cocks aged 1 to 21 days in the AHLase-5000 group significantly increased compared with the control group(P<0.05);the feed to gain of cocks aged 22 to 42 days and 1 to 42 days significantly decreased(P<0.05).The final weight of hens aged 22 to 42 days in the AHLase-5000 group significantly increased(P<0.05),while the average daily feed intake of hens aged 1 to 42 days in the AHLase group significantly decreased(P<0.05).2)Throughout the experimental period,cocks exhibited significantly higher average daily gain and average daily feed intake compared with hens(P<0.05).The feed to gain of cocks aged 1 to 21 days showed a trend higher than that of hens(P=0.075).Gender showed a significant trend in the final weight of broiler chickens aged 1 to 21 days(P=0.079).3)The supplementation of AHLase led to a significant increase in the average daily feed intake of broilers aged 1 to 21 days(P<0.05).There was also an increasing trend in the average daily gain(P=0.052),and a significant decrease in the feed to gain(P<0.05).The final weight of broiler chickens aged 22 to 42 days significantly increased(P<0.05).4)The interaction effects of AHLase supplementation level and gender were observed in the average daily feed intake from 1 to 21 days of age,average daily feed intake from 22 to 42 days of age,and feed to gain from 1 to 42 days of age(P<0.05).There was also an interaction trend observed in the feed to gain from 22 to 42 days of age(P=0.069)and average daily gain from 1 to 42 days of age(P=0.064).5)The addition of AHLase in the diet did not have a significant effect on the blood routine and serum biochemical indexes of broilers(P>0.05).6)The inclusion of AHLase in the diet did not have a significant impact on the organ indexes of broilers(P>0.05),and no morphological structure changes were observed in the tissues.The results indicate that the inclusion of 5000 mg/kg of AHLase in the broiler diet leads to a significant improvement in growth performance.However,it does not have a noticeable effect on blood biochemical indexes and visceral organ development.These findings suggest that broilers can tolerate AHLase at doses exceeding 5000 mg/kg.