甜菜碱对肉鸭体内脂肪代谢的影响

Effect of Betaine on Carcass Fat Metabolism of Meat Duck

54 0只 2 1日龄商品代樱桃谷肉鸭根据体重相近、公母各半的原则分成 5个组 ,分别为对照组和 4个甜菜碱处理组。每组 1 0 8只 ( 3 6× 3 ) ,每组设 2个重复 ,每个重复 3 6只。对照组饲粮中不添加甜菜碱 ,试验 1～4组饲粮中甜菜碱的添加量分别为 2 50、50 0、750、1 0 0 0 mg/kg。饲养试验结束后 ,60只被屠宰用于胴体测定(每组 6公、6母 )。结果表明 ,甜菜碱显著降低了肉鸭的腹脂率 ( P <0 .0 5)、皮脂厚 ( P <0 .0 5)和肝脏粗脂肪含量 ( P<0 .0 5) ,明显提高了肉鸭肌间脂肪 ( P<0 .0 5)和胸肌粗脂肪的含量 ( P <0 .0 5)。进一步分析表明 ,在肉鸭饲粮中添加 1 0 0 0 mg/kg甜菜碱显著提高了甜菜碱高半胱氨酸甲基转移酶 ( BHMT)总活力和比活力( P <0 .0 1 )、肝脏游离肉碱含量 ( P <0 .0 1 )和胸肌脂酰肉碱的含量 ( P <0 .0 1 ) ,明显降低了肉鸭腹脂NADPH脂肪生成酶 ( G-6-PD、MDH、ICD)的活性 ( P <0 .0 5) ,显著提高了肉鸭血清中生长激素 ( GH)水平( P <0 .0 1 )。结果揭示 ,甜菜碱通过增强甲基代谢 ,加强了肉碱合成 ,促进了长链脂肪酸β-氧化 ,同时通过刺激 GH分泌 ,抑制脂肪合成酶活性 。

Five hundred and forty 21 day old commercial strain Cherry Valley meat duck of equal male and female were randomly allocated into the five groups with two replicates for a three weeks feeding trial.The experiment involved five dietary levels of betaine supplementation(Control:0 mg/kg betaine;Treat 1: 250 mg/kg,Treat 2: 500 mg/kg, Treat 3: 750 mg/kg and Treat 4: 1 000 mg/kg betaine).Once finishing feeding trial,sixty ducks from each replicate(two male,two female) of five groups were selected for determining carcass trait.The results showed that betaine supplementation significantly decreased PDAF(Percentage of Dissected Abdominal Fat)(P<0.05),SFD(Subcutaneous Fat Depth)(P<0.05) and the crude fat content of liver(P<0.05),while significantly increased IMFD(Inter Muscular Fat Depth)(P<0.05) and the crude fat content of breast muscle(P<0.05). Data from biochemistry analysis showed that betaine significantly increased the total activities and specific activities of BHMT(Betaine Homocysteine Methyl Transferase),free carnitine content of liver and acid insoluble carnitine content of breast muscle.Betaine also significantly decreased the activities of NADPH enzyme(G 6 PD,MDH,ICD),and significantly increased the GH(Growth Hormone) levels in serum. The results implied that the betaine can effectively exert the effect of reduction of carcass fat and repartition of carcass fat by improving the β oxidation of long chain fatty acid, stimulating the secretion of GH and inhibiting the activities of NADPH enzyme.