酵母硒对肉仔鸡的生物安全性评价

Evaluation of the Biological Safety of Selenium Yeast for Broilers

本试验旨在研究饲粮添加不同水平酵母硒对爱拔益加(AA)肉仔鸡生长性能、血液血红蛋白含量和红细胞压积、血浆生化指标、器官指数和组织结构变化的影响,进而评价酵母硒对肉仔鸡的生物安全性。试验采用单因子完全随机设计,选用288只1日龄AA肉仔鸡,随机分为4个组,每个组6个重复,每个重复12只鸡(公母各占1/2)。各组分别在玉米-豆粕型基础饲粮中添加0、0.4、2.4和4.9 mg/kg(以硒计)的酵母硒试验。试验期为42 d。结果表明:1)与对照组相比,饲粮添加0.4和2.4 mg/kg酵母硒显著提高了22~42日龄肉仔鸡平均日采食量(P<0.05);饲粮添加0.4、2.4和4.9 mg/kg酵母硒显著提高了1~42日龄肉仔鸡平均日增重(P<0.05),而各酵母硒添加组之间差异不显著(P>0.05)。2)饲粮添加不同水平酵母硒除对21日龄肉仔鸡血浆尿素氮含量和谷胱甘肽过氧化物酶(GSH-Px)活性以及42日龄肉仔鸡血浆GSH-Px活性有显著影响(P<0.05)外,对其他血浆生化指标均无显著影响(P>0.05)。与对照组相比,各酵母硒添加组21和42日龄肉仔鸡血浆GSH-Px活性随着酵母硒添加水平的增加均显著提高(P<0.05),且饲粮添加2.4 mg/kg酵母硒显著降低了21日龄肉仔鸡血浆尿素氮含量(P<0.05)。3)饲粮添加不同水平酵母硒对21和42日龄肉仔鸡血液血红蛋白含量和红细胞压积及42日龄肉仔鸡器官指数均无显著影响(P>0.05),且并未引起主要器官的组织结构变化。综上所述,肉仔鸡饲粮中酵母硒的添加水平为0.4 mg/kg(饲粮中总硒含量为0.41 mg/kg)时,具有10倍的安全系数,即饲粮中以酵母硒形式添加硒对肉仔鸡是安全的。

This experiment was conducted to investigate the effects of dietary different supplemental levels of selenium yeast on growth performance, hemoglobin content and hematocrit in blood, plasma biochemical parameters, organ indices and histopathological changes of Arbor Acres （AA） broilers so as to evaluate the biological safety of selenium yeast for broiler chicks.A total of 288 one-day-old AA broilers were randomly allocated into four groups with six replicates per group and twelve broilers per replicate （half male and half female） in a completely randomized design. Broilers were fed the corn-soybean meal basal diets supplemented with 0, 0.4, 2.4 or 4.9 mg/kg selenium yeast （as selenium）. The experiment lasted for 42 days. The results showed as follows： 1） compared with the control group, dietary supplemented with 0.4 and 2.4 mg/kg selenium yeast significantly increased the average daily feed intake of broilers during 22 to 42 days of age （P〈0.05）, dietary supplemented with 0.4, 2.4 and 4.9 mg/kg selenium yeast significantly increased the average daily gain of broilers during 1 to 42 days of age （P〈0.05）, but no significant differences were found in the above two indices among all the selenium yeast groups （P〉0.05）. 2） Except dietary different supplemental levels of selenium yeast significant affected the urea nitrogen content and glutathione peroxidase （GSH-Px） activity in plasma of broilers at 21 days of age and plasma GSH-Px activity of broilers at 42 days of age （P〈0.05）, but did not affect the other plasma biochemical parameters （P〉0.05）. Compared with the control group, the plasma GSH-Px activity of broilers at 21 and 42 days of age in selenium yeast groups was significantly increased as dietary selenium yeast level increased （P〈0.05）, and dietary supplemented with 2.4 mg/kg selenium yeast significantly decreased plasma urea nitrogen content of broilers at 21 days of age （P〈0.05）. 3） Dietary different supplemental levels of selenium yeast had no significant effects on hemoglobin content and hematocrit in blood of broilers at 21 and 42 days of age and organ indices of broilers at 42 days of age （P〉0.05）, and did not cause the histopathological changes of major organs. These results indicate that when dietary supplemental level of selenium yeast is 0.4 mg/kg （dietary total selenium content is 0.41 mg/kg）, the supplemental level of chromium （as selenium yeast） to diet which is 10 times of the allowance will be safe for broilers.