Abstract:

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).

Key words: Bamei lambs, body weight, muscle fiber characteristics, meat quality