不同锰源对肉鸡胴体性能和肌肉品质的影响

 【目的】用336只1日龄AA肉公鸡进行试验，研究饲粮添加不同锰源对肉鸡胴体性能、肌肉品质、腹脂和肌肉中相关酶活性及肌肉中MnSOD mRNA水平的影响。【方法】采用3×3两因子安排的完全随机设计，将试鸡按体重随机分为7个处理组，分别饲喂不添加锰的玉米-豆粕型基础饲粮和在基础饲粮中以无机硫酸锰、氨基酸锰A（Mn AA A）和氨基酸锰B（Mn AA B）形式分别添加100和200mg?kg-1锰的试验饲粮，试验期为42 d。【结果】添加锰对肌肉pH、滴水损失、剪切力、肌间脂肪、L* 值、a* 值等均无显著影响 (P﹥0.10)；各添加锰组鸡腹脂率、腹脂脂蛋白脂酶（LPL）和苹果酸脱氢酶（MDH）活性及腿肌丙二醛（MDA）含量显著低于未添加锰的对照组 (P﹤0.10)，添加Mn AA A组和添加Mn AA B组腹脂LPL活性均显著低于添加MnSO4组（P﹤0.05）；各添加锰组腹脂激素敏感脂酶（HSL）活性、胸肌和腿肌细胞线粒体中MnSOD活性和MnSOD mRNA水平均显著高于未添加锰的对照组（P﹤0.02）， 添加Mn AA A组腿肌细胞线粒体中MnSOD mRNA水平显著高于添加无机硫酸锰组（P﹤0.02）。【结论】中等络合强度有机锰（Mn AA A）比无机硫酸锰更能有效降低肉鸡腹脂LPL活性及增强腿肌细胞线粒体中MnSOD的基因表达,并进而改善了肉鸡胴体性能和肌肉品质。

Effect of Dietary Manganese Source on Carcass Traits and Meat Quality in Broiler Chickens

An experiment was conducted using a total of 336 day-old AA male broilers to investigate the effect of dietary manganese (Mn) source on carcass traits, meat quality, relative enzyme activities in abdominal fat and meat, and MnSOD mRNA level in meat. The broilers were randomly allotted to one of seven treatments in a completely randomized design involving a 3×3 factorial arrangement of treatments and fed the corn-soybean meal basal diets and the basal diet supplemented with 100 or 200 mg Mn/kg as Mn sulfate (MnSO4?H2O), Mn amino acid A (Mn AA A) or Mn amino acid B (Mn AA B) with moderate chelation strength, respectively, for a duration of 42 days. Birds fed diets supplemented with Mn had lower (P﹤0.10) percentages of abdominal fat, lipoprotein lipase (LPL) and malate dehydrogenase (MDH) activities in abdominal fat, and malondialdehyde (MDA) content in leg muscle than those fed the control diet. Birds fed diet supplemented with Mn from Mn AA A or Mn AA B had lower (P﹤0.05) LPL activities in abdominal fat than those fed diet supplemented with Mn sulfate. Birds fed diets supplemented with Mn had higher (P﹤0.02) hormone sensitive lipase (HSL) activities in abdominal fat, and Mn-containing superoxide dismutase (MnSOD) activities and mRNA level in breast and leg muscle mitochondria. Birds fed diets supplemented with Mn from Mn-AA A had higher (P﹤0.02) MnSOD mRNA level in leg muscle mitochondria than those fed diets supplemented with Mn from Mn sulfate. The results indicate that organic Mn with the moderate complex strength (Mn AA A) was more available than inorganic Mn source to decrease LPL activity in abdominal fat and increase MnSOD gene expression in mitochondria of leg muscle cells in broilers, leading to the improvement of carcass traits and meat quality.