Studies on Regulation of Lipid Metabolism and Egg Production in Laying Hens.

1)研究了日粮中添加泛氨酸对以玉米或大麦为碳源的单梳白来航产蛋鸡产蛋量、肝脏脂肪生成及肝脏和腹部脂肪组织中脂肪积累的影响。饲喂玉米基础日粮的母鸡肝脏中脂肪含量和成脂相关酶活性高于饲喂大麦基础日粮的母鸡。肝脏脂肪含量、腹脂含量和肝脏脂肪生成量均显著降低。基础日粮中添加泛氨酸。然而，在大麦基础日粮中添加泛氨酸对肝脏的脂肪含量和脂肪生成没有显示出任何显著的影响。在玉米基础日粮中添加泛氨酸的这些效应表现为降低血浆雌二醇水平，从而降低血浆甘油三酯浓度，从而减少脂肪酸从血液到脂肪组织的运输。2)在31ﾟC的环境温度下，研究了在饲喂玉米或大麦的日粮中添加泛氨酸对蛋鸡产蛋量和肝脏脂肪积累和脂肪生成的影响。在试验日粮中添加泛替丁不会影响每日饲料消耗量，但可以提高蛋鸡的产蛋量和蛋重。因此，根据这些结果，我们倾向于认为，只有在环境温度较高的情况下，添加泛氨酸对产蛋率和蛋重的影响才明显，而在环境温度较低的情况下，添加泛氨酸的能力不明显。(3)通过体外培养的母鸡肝细胞，研究了泛氨酸对肝脏脂肪生成的影响。在孵育液中加入泛氨酸后，肝细胞的脂肪生成减少。特别是，添加泛氨酸后，胆固醇的生物合成明显减少。

1) Effects of dietary pantethine supplementation on egg production, hepatic lipogenesis and on lipid accumulation of the liver and the abdominal fat tissue were studied in Single Comb White Leghorn laying hens fed diets containing corn or barley as the carbohydrate source. Lipid content and lipogenic-related enzyme activities in the liver in hens fed the corn basal diet than in those fed the barley basal diet. Lipid contents of the liver and abdominal fat and hepatic lipogenesis were significantly reduced, when the corn. basal diet was supplemented with pantethine. However, pantethine supplementation to the barley basal diet failed to show any significant effect on the lipid content and lipogenesis of the liver. These effects of pantethine supplementation to the corn basal diet manifested itself via depression of the 170-estradiol level, which in turn decreased plasma triglyceride concentration and consequently resulted in reduced fatty acid transport from blood to adipose tissues.2) Effects of dietary pantethine supplementation on egg production and on lipid accumulation and lipogenesis of the liver were studied laying hens fed diets with corn or barley, under 31ﾟC of environmental temperature. Pantethine added to experimental diets did not affect daily feed consumption, but improved egg production and egg weight. Thus, based on these results, we are inclined to conclude that the ability of pantethine supplementation to egg production rate and egg weight is evident only when the environmental temperature is high, but not when it is low.(3)Effects of pantethine on hepatic lipogenesis were studied in vitro by isolated hepatocytes of hens. Lipogenesis of isolated hepatocytes decreased by pantethine addition to incubation medium. Especially, cholesterol biosynthesis showed a marked decrease by added pantethine.