甜菜碱对肥育猪胴体组成的影响及其作用机理的探讨

EFFECT OF BETAINE ON CARCASS CHARACTERISTICS AND APPROACH TO MECHANISM OF THE EFFECT IN FINISHING SWINE

用不同甜菜碱添加量（０、１０００、１２５０、１５００和１７５０ｍｇ／ｋｇ）的同种饲粮，分别饲喂５组（１５０头）杜长大肥育猪（６３ｋｇ）４０ｄ，进行屠宰试验，并对血液、肝脏、背最长肌和皮下脂肪有关生化指标进行分析。结果表明：添加甜菜碱明显改善了胴体组成，以１０００ｍｇ／ｋｇ组效果最显著；不同剂量甜菜碱均使肝脏甜菜碱——高半胱氨酸甲基转移酶和胱硫醚β－合成酶的活性发生了变化，前者以１０００ｍｇ／ｋｇ添加量最为显著，其比活力提高了１５．６３％（Ｐ＜０．０１），后者则以１７５０ｍｇ／ｋｇ添加量最为明显，其比活力提高了２８．０７％（Ｐ＜０．０５）；添加１７５０ｍｇ／ｋｇ甜菜碱亦显著提高了肝脏肌酸、游离肉碱和酸不溶肉碱含量（Ｐ＜０．０１）；添加高剂量（１７５０ｍｇ／ｋｇ）甜菜碱，背最长肌中酸不溶肉碱及酸不溶肉碱／游离肉碱比率分别提高了５３．３３％和４４．１２％（Ｐ＜０．０１），ＲＮＡ含量及ＲＮＡ／ＤＮＡ比值分别提高了１７．６０％和２５．９６％（Ｐ＜０．０５）；添加不同剂量甜菜碱均显著降低了皮下脂肪苹果酸脱氢酶活力（Ｐ＜０．０５）；甜菜碱可提高血清生长激素（ＧＨ）水平，并与添加剂量呈一定正相关，１７５０ｍｇ／ｋｇ组ＧＨ提?

One hundred fifty finishing pigs (Duroc×Landrace×Yorkshire)were allotted to five groups which received the same basal diet,supplemented with 0, 1 000, 1 250, 1 500, 1 750 mg/kg betaine On finishing 40 days feeding experiment,60 pigs were slaughtered,the liver,etc samples were collected and analysed The results indicated:Adding betaine changed the acitivity of betaine homocysteine transermase and cystathinone β synthetase in liver The contents of the free carnitine,acid insoluble carnitine and creatine in liver were significant increased in 1 750mg/kg group Furthermore,adding 1 750mg/kg betaine increased the contents of acid insoluble carnitine,acid insoluble carnitine/free carnitine ration,RNA content and the RNA/DNA ratio in longissimus dorsi by 53 53%、44 12%(P<0 01),17 60%and 25 41%(P<0 05) respectively The malic dehydrogenase activites of the subcutaneous fat were decreased significantly in all test groups The study first found that betaine could enhance the serum growth hormone (GH) level and the response presented the positive correlation with the betaine dosage.GH was enhanced by 59 16%(P<0 02)in 1 750 mg/kg group Betaine was also of the ability that decreasing the content of serum urine nitrogen which was decreased by 37 03%(P<0 01) at 1 000 mg/kg dose