斜率比法评定肉仔鸡对铜源的相对生物学利用率

Evaluation of Relative Bioavailability of Copper Source with Slope Ratio Method for Broilers

本试验旨在研究肉仔鸡对不同铜源的相对生物学利用率。试验采用3×2完全随机设计,3种铜源分别为硫酸铜、碱式氯化铜和蛋氨酸铜,2个铜添加水平分别为10和20 mg/kg,另设1个不添加铜的对照组,共7组。选择1日龄健康雄性爱拔益加(AA)肉仔鸡504只,随机分为7组,每组6个重复,每个重复12只鸡。试验期为21 d。结果表明:饲粮铜源和铜添加水平对1～21日龄肉仔鸡的末重、平均日采食量、平均日增重和料重比均无显著影响(P> 0. 05)。肝脏铜含量和血浆铜蓝蛋白活性均随饲粮铜添加水平的增加而极显著增加(P<0.01)。以血浆铜蓝蛋白活性为评价指标,碱式氯化铜和蛋氨酸铜相对于硫酸铜(100%)的生物学利用率分别为141.05%和142.07%;以肝脏铜含量为评价指标,碱式氯化铜和蛋氨酸铜相对于硫酸铜(100%)的生物学利用率分别为127.61%和137.64%。由此可见,饲粮铜添加水平≤20 mg/kg(基础饲粮中铜含量为9.65 mg/kg)时对1～21日龄肉仔鸡无显著促生长作用; 21日龄肉仔鸡对低铜饲粮(铜添加水平≤20 mg/kg)中3种铜源的相对生物学利用率为:蛋氨酸铜>碱式氯化铜>硫酸铜。

This study was conducted to evaluate the relative bioavailability of different copper (Cu) source for broilers. According to 3×2 factorial completely randomized test design,three Cu sources (copper sulfate,tribasic copper chloride and copper methionine) and 2 Cu supplemented levels (10 and 20 mg/kg) as the two main factors,control group without Cu supplementation,and 7 groups were formed. A total of 504 1-day-old healthy male Arbor Acres (AA) broilers were randomly divided into 7 groups with 6 replicates per group and 12 broilers per replicate. The experiment lasted for 21 days. The results showed that dietary Cu source and Cu supplemented level had no significant effects on final body weight,average daily feed intake,average daily gain and the ratio of feed to gain of broilers aged from 1 to 21 days ( P >0.05). The content of Cu in liver and the activity of ceruloplasmin in plasma were significantly increased with dietary Cu supplemented level increased ( P <0.01). Compared with copper sulfate (100%),relative bioavailability of tribasic copper chloride and copper methionine were 141.05% and 142.07% based on the activity of ceruloplasmin in plasma as evaluating indicator,respectively;and relative bioavailability of tribasic copper chloride and copper methionine were 127.61% and 137.64% based on the content of Cu in liver as evaluating indicator,respectively. In conclusion,dietary Cu supplemented level less than 20 mg/kg (the content of Cu in basal diet is 9.65 mg/kg) has no significant growth-promoting effects on broilers aged from 1 to 21 days,and the relative bioavailability of 3 Cu sources in low-copper diets (Cu supplemented level less than 20 mg/kg) for broilers aged 21 days is copper methionine>tribasic copper chloride>copper sulfate.