肉鸡对不同形态锰源的生物利用率研究

THE RELATIVE BIOAVAILABILITIES OF MANGANESE SOURCES FOR BROILERS

目的 : 研究肉仔鸡对不同形态锰源的相对生物学利用率。方法 : 将 62 4只 1日龄肉公鸡随机分为 1 3组 ,分别饲不添加锰的基础饲粮 (对照组 )或以不同锰化合物添加 60、1 2 0、1 80 mg/ kg锰的试验饲粮 2 1 d。结果 : 肉鸡生长性能各指标和腿病发生率以及肉鸡的跖骨灰锰含量、心肌细胞线粒体中 Mn SOD活性均未受到添加锰源以及锰源与锰水平互作的显著影响 ,但受到添加锰水平的显著影响。肉鸡心肌含锰量和 Mn SOD m RNA水平均未受到添加锰源与锰水平互作的显著影响 ,但受到添加锰源及添加锰水平的显著影响。其中中等和强络合强度有机锰源的生物学利用率明显高于无机硫酸锰和弱络合强度有机锰源。结论

Objective: To study the relative bioavailabilities of Mn sources for broilers. Methods: A total of 624 one day old broilers were randomly allotted to one of thirteen groups and fed corn soybean meal basal diet (control) or the basal diet supplemented with 60, 120, 180 mg/kg Mn as compounds of different Mn for 21 d. Results: The growth performance incidence of leg abnormality of chicks ,metatarsal bone ash Mn content and heart MnSOD activity,in different groups of Mn source or source×level interaction were not significantly different. However, these two indices were affected by Mn level.Based on slope ratios from multiple linear regressions of these two indices on daily intake of dietary added Mn, the relative bioavailabilities of Mn Met E, Mn AA B, and Mn AA C were 103.8%, 102.4%, and 101.8% for bone ash Mn, and 108.3%, 107.8%, and 120.0% for heart MnSOD activity if 100% was set for Mn sulfate, respectively. Heart Mn content and MnSOD mRNA level were affected by Mn source and Mn level . Based on slope ratios from multiple linear regression of these two items on dietary supplemental Mn intake, the relative bioavailabilities of Mn Met E, Mn AA B, and Mn AA C were 125.7%, 137.2%, and 135.1% for heart Mn content, and 111.8%, 144.8% and 147.7% for MnSOD mRNA level compared to 100% of Mn sulfate, respectively. Mn AA B and Mn AA C were more available (P<0.05) than Mn sulfate and Mn Met E. Mn AA C, and Mn Met E had tendency to be superior to Mn sulfate numerically ( P>0.10 ). Conclusion: Dietary Mn significantly affected heart MnSOD gene expression pret ranslationally, and heart MnSOD gene expression as a criterion for relative bioavailability. Organic Mn sources with moderate or strong complex strength were more available than Mn sulfate or organic Mn source with weak complex strength.