基因型、年龄和性别对羊肉胆固醇含量的影响

Effects of genotype, sex and age on cholesterol level of the sheep meat

实验选用兰得瑞斯羊及其杂种为实验动物，采用冷式提取脂肪的方法以及气相色谱(GC)技术测定了肉羊背最长肌肌肉中胆固醇含量。实验研究了不同基因型、不同年龄以及不同性别肉羊肌肉中的胆固醇的变化以及这些因素对肉中胆固醇含量的影响。研究结果表明，年龄对脂肪中胆固醇含量有明显地影响作用。羊肉脂肪中的胆固醇含量随个体年龄的增长而下降。肌肉中胆固醇的含量以50日龄时为最高，达到748mg/kg，150日龄时胆固醇含量374mg/kg为最低，100日龄时胆固醇含量居中为502mg/kg。3个实验组的差异极显著 (P<0.01)。虽然单从实验的数字上看，纯种肉羊和75 % 杂种羊脂肪中胆固醇的含量比50 % 杂种羊的要高，但性别和基因型对羊体脂中胆固醇的含量影响都不显著(P>0.05)。还表明，羊肉脂肪中的胆固醇含量随着年龄的增长而下降，幼年肉羊肌肉中的胆固醇相对含量要显著的高于成年羊。因为，成年羊的体脂中饱和性脂肪酸的含量高于羔羊。因此，无论从市场角度还是从健康角度看，羊肉的生产以1岁左右的羊为最佳。

This study aim to evaluated the level of the cholesterol in the sheep meet and to determine the effects of the age and genotype and sex on the level of cholesterol of the sheep meat. The Landrace sheep and its crossbreeds were used as an experimental animal and longissmus muscle was taken as the sample for cholesterol analysis. Cold Extraction method and GC procedure was applied for fat extraction and cholesterol analysis. The result showed that sheep at the age of 50 days contains highest level of cholesterol in its meet while the sheep at the age of 150 days contains the lowest level of cholesterol. There were significant differences among the three groups (P<0.01). On the other hand，there were no effects of sex and genotype on the cholesterol level of the meat found in this experiment.