Hou Yanru, Su Lin, Su Rina, Luo Yulong, Wang Bohui, Yao Duo, Zhao Lihua, Jin Ye
College of Food Science and Engineering Inner Mongolia Agricultural University Hohhot China.
Food Sci Nutr. 2020 Apr 14;8(5):2262-2270. doi: 10.1002/fsn3.1494. eCollection 2020 May.
The effects of two feeding regimens on meat quality, myosin heavy chain (MyHC) types, and key factors regulating muscle fiber type (AMP-activated protein kinase [AMPK] and peroxisome proliferator-activated receptor-coactivator-1α [PGC-1α]) in the biceps femoris muscle of Mongolia sheep were investigated. A total of 20 Mongolia sheep were weaning for 90 days and divided into two groups (pasture group (P) and confinement group (C)) at 10.36 ± 0.35 kg of weaning weight. After weaning, sheep were pasture fed or confinement fed for 9 months. The results showed that live weights, carcass weight, intramuscular fat (IMF), and Warner-Bratzler shear force (WBSF) in P group were significantly lower ( < .05) than that in C group. Compared with P group, color evaluations with respect to L* and b* values were significantly higher ( < .05) in C group. Expression of the MyHC I gene in the P group was significantly higher, while MyHC IIa and MyHC IIb genes expression was significantly lower ( < .05) than that in C group. Also, AMPK activity and expression of AMPKα2 and PGC-1α genes were significantly higher ( < .05) in P group compared with C group. The present study indicated that muscle fiber composition was one of the key differences leading to the differences of meat quality in different feeding regimens. AMPK, particularly AMPKα2, and PGC-1α were considered to be two key factors regulating muscle fiber types in Mongolia sheep. The results support that AMPK activity and the expression of AMPKα2 and PGC-1α genes may affect the composition of muscle fibers; thus, AMPK activity and the expression of AMPKα2 and PGC-1α genes had an effect on meat quality by changed composition of muscle fibers.
研究了两种饲养方式对蒙古羊股二头肌肉质、肌球蛋白重链（MyHC）类型以及调节肌纤维类型的关键因子（AMP激活的蛋白激酶[AMPK]和过氧化物酶体增殖物激活受体协同激活因子1α[PGC-1α]）的影响。选取20只断奶90天的蒙古羊，断奶体重为10.36±0.35千克，分为两组（放牧组[P]和舍饲组[C]）。断奶后，羊分别进行9个月的放牧饲养或舍饲饲养。结果表明，P组的活重、胴体重、肌内脂肪（IMF）和沃纳-布拉茨勒剪切力（WBSF）显著低于C组（P<0.05）。与P组相比，C组L和b值的颜色评价显著更高（P<0.05）。P组MyHC I基因的表达显著更高，而MyHC IIa和MyHC IIb基因的表达显著低于C组（P<0.05）。此外，与C组相比，P组的AMPK活性以及AMPKα2和PGC-1α基因的表达显著更高（P<0.05）。本研究表明，肌纤维组成是导致不同饲养方式下肉质差异的关键因素之一。AMPK，尤其是AMPKα2和PGC-1α被认为是调节蒙古羊肌纤维类型的两个关键因子。结果支持AMPK活性以及AMPKα2和PGC-1α基因的表达可能影响肌纤维组成；因此，AMPK活性以及AMPKα2和PGC-1α基因的表达通过改变肌纤维组成对肉质产生影响。
