Hyogo Prefectural Technology Center of Agriculture, Forestry, and Fisheries, Kasai, Japan.
Anim Sci J. 2009 Aug;80(4):411-7. doi: 10.1111/j.1740-0929.2009.00648.x.
The effects of the fattening period on carcass characteristics, fatty acid composition of fat deposits, and muscle free amino acid (FAA) and inosinic acid (IMP) contents were evaluated in Japanese Black steers. Ten castrated, 10-month-old calves derived from the same sire were divided into five to be slaughtered at the age of 30 months after a 20-month fattening period (20-month group) and five to be slaughtered at the age of 34 months after a 24-month fattening period (24-month group). Concerning the fatty acid composition of subcutaneous fat, the percentage of palmitoleic acid was higher (P < 0.05) in the 24- than in the 20-month group, but no difference was noted in any other fatty acids. For intermuscular fat, no difference was observed in any fatty acids. The percentages of oleic acid and total monounsaturated fatty acid of intramuscular and perinephric fat were higher (P < 0.05) in the 24- than in the 20-month group. Of the FAAs in the longissimus thoracis muscle, the threonine and tyrosine contents were lower (P < 0.05) in the 24- than in the 20-month group. The IMP content was higher (P < 0.05) in the 24- than in the 20-month group, suggesting an effect of prolongation of the fattening period.
在日本黑牛肉牛中评估育肥期对胴体特性、脂肪沉积的脂肪酸组成以及肌肉游离氨基酸（FAA）和肌苷酸（IMP）含量的影响。10 头去势的 10 月龄小牛来自同一头公牛，分为两组，每组 5 头，分别在育肥 20 个月后（20 月龄组）和育肥 24 个月后（24 月龄组）在 30 月龄时屠宰。关于皮下脂肪的脂肪酸组成，24 月龄组的棕榈油酸百分比高于 20 月龄组（P <0.05），但其他脂肪酸没有差异。对于肌肉间脂肪，任何脂肪酸都没有差异。24 月龄组肌肉和肾周脂肪的油酸和总单不饱和脂肪酸百分比高于 20 月龄组（P <0.05）。胸最长肌中的游离氨基酸中，苏氨酸和酪氨酸含量在 24 月龄组低于 20 月龄组（P <0.05）。24 月龄组的 IMP 含量高于 20 月龄组，表明育肥期延长的影响。
