体质量对巴美肉羊肌纤维特性及肉品质的影响

本实验以3 组不同体质量（30～40、40～50、50～60 kg）巴美肉羊的臂三头肌为材料，用ATP酶组织化学染色法，研究体质量对肌纤维特性以及肉品质的影响。结果表明：30～40 kg羊的Ⅰ型肌纤维横截面积显著小于其他两个体质量组（P＜0.05）；50～60 kg羊的ⅡA型肌纤维直径显著大于其他两个体质量组（P＜0.05），而数量比例和面积比例显著小于其他两个体质量组（P＜0.05）；50～60 kg羊的ⅡB型肌纤维的面积比例显著高于其他两个体质量组（P＜0.05）。30～40 kg羊肉亮度（L*）值显著低于50～60 kg羊（P＜0.05），而剪切力极显著高于50～60 kg羊（P＜0.01）；体质量与Ⅰ型肌纤维的直径呈显著正相关（P＜0.05），与Ⅰ型肌纤维的横截面积和ⅡA型肌纤维的直径呈极显著正相关（P＜0.01），与ⅡA型肌纤维数量比例和面积比例呈极显著负相关（P＜0.01）。

Effect of Body Weight on Muscle Fiber Characteristics and Meat Quality of Bamei Lambs

The aim of this study was to investigate the effect of three different body weights on muscle fiber characteristics
and meat quality traits in triceps brachii muscle of Bamei lambs by ATPase histochemical staining technique. The results
showed that the cross-sectional area of type Ⅰ muscle fiber from 30-40 kg lambs was significantly lower than that of
lambs with higher body weights (P ＜ 0.05). The diameter of type ⅡA muscle fiber and the proportion by area of type ⅡB
muscle fiber from 50-60 kg lambs were significantly increased over that of lambs with smaller body weights (P ＜ 0.05),
whereas the proportions by number and area of type ⅡA muscle fiber from the heavier lambs were significantly smaller
(P ＜ 0.05). The 30-40 kg lambs had significantly lower L* value and higher Warner-Bratzler shear force than the 50–60 kg ones
(P ＜ 0.05). Body weight was correlated significantly positively with the diameter and cross-sectional area of type Ⅰ muscle
fiber and type ⅡA muscle fiber diameter (P ＜ 0.05), but highly significantly negatively with the proportions by number and
area of type ⅡA muscle fiber (P ＜ 0.01).