Eichhorn J M, Coleman L J, Wakayama E J, Blomquist G J, Bailey C M, Jenkins T G
J Anim Sci. 1986 Sep;63(3):781-94. doi: 10.2527/jas1986.633781x.
Fatty acid composition and cholesterol content of muscle and adipose tissue from mature cows (N = 101) representing 15 breeds and crosses were determined. An initial group of cows was slaughtered after being fed slightly above the maintenance level for 2 wk; the remaining cows were fed either at the maintenance level or ad libitum for 84 d, then slaughtered. Samples of triceps brachii and longissimus muscle and subcutaneous and perinephric adipose tissue were obtained from each carcass. In addition, phospholipid and triacylglycerol fatty acids from total lipid extracts of triceps brachii muscle and subcutaneous adipose tissue were analyzed for 24 cows that were fed ad libitum or at the maintenance level for 84 d. Breed type effects on fatty acid composition were more pronounced in adipose tissue than in muscle tissue. Total lipid extracts of both triceps brachii and longissimus muscle from animals fed a maintenance diet for 84 d contained higher (P less than .01) percentages (3 to 8%) of polyunsaturated fatty acids (PUFA) and lower percentages (2 to 3%) of saturated fatty acids (SFA) than those from animals fed ad libitum for 84 d. This reflected significant variation in the fatty acids C14:0, C16:0, C18:2, C18:3 and C20:4 for both longissimus and triceps brachii muscle. Fatty acid composition within phospholipid and triacylglycerol fractions was similar regardless of maintenance or ad libitum feeding. Much of the variation in total lipid fatty acid composition appeared to be the result of differences in triacylglycerol:phospholipid ratios. Adipose tissue contained about twice as much cholesterol (mg/100 g wet weight) as muscle tissue. Both breed type and feeding group effects on cholesterol content of muscle tissue were nonsignificant. Values for cholesterol content of adipose tissue from cows fed restricted diets were higher than those from cows fed ad libitum (approximately 55 mg/100 g higher for subcutaneous and 25 mg/100 g for perinephric). The results show that changes in fatty acid composition of bovine tissues can be made genetically and by varying the energy level in the diet. Alteration of the cholesterol content of muscle tissue by these methods does not appear to be feasible.
测定了代表15个品种及杂交品种的101头成年母牛肌肉和脂肪组织的脂肪酸组成及胆固醇含量。最初一组母牛在维持水平以上饲养2周后屠宰；其余母牛分别按维持水平或自由采食84天，然后屠宰。从每具胴体采集肱三头肌、背最长肌以及皮下和肾周脂肪组织样本。此外，对24头按维持水平或自由采食84天的母牛，分析了肱三头肌和皮下脂肪组织总脂质提取物中的磷脂和三酰甘油脂肪酸。品种类型对脂肪酸组成的影响在脂肪组织中比在肌肉组织中更显著。采食维持日粮84天的动物，其肱三头肌和背最长肌的总脂质提取物中多不饱和脂肪酸（PUFA）的百分比（3%至8%）更高（P小于0.01），饱和脂肪酸（SFA）的百分比（2%至3%）更低，高于自由采食84天的动物。这反映出背最长肌和肱三头肌中C14:0、C16:0、C18:2、C18:3和C20:4脂肪酸有显著差异。无论维持饲养还是自由采食，磷脂和三酰甘油组分中的脂肪酸组成相似。总脂质脂肪酸组成的大部分差异似乎是三酰甘油与磷脂比例不同的结果。脂肪组织中的胆固醇含量（毫克/100克湿重）约为肌肉组织的两倍。品种类型和饲养组对肌肉组织胆固醇含量的影响均不显著。限饲母牛脂肪组织的胆固醇含量高于自由采食母牛（皮下脂肪约高55毫克/100克，肾周脂肪高25毫克/100克）。结果表明，牛组织脂肪酸组成的变化可通过遗传和改变日粮能量水平来实现。用这些方法改变肌肉组织的胆固醇含量似乎不可行。
