Muscle fiber characteristics of pectoralis major muscle as related to muscle mass in different Japanese quail lines

Abstract

The objectives of this study were to investigate the muscle fiber characteristics of the pectoralis major muscle, and its relation to growth performance in the random bred control (RBC) and heavy weight (HW) Japanese quail lines at 42 days of age. The HW line had greater body (232.0 v. 100.2 g, P , 0.001) and pectoralis major muscle (19.0 v. 6.2 g, P , 0.001) weights than the RBC line. Color differences were observed between the superficial and deep regions of the pectoralis major muscle, with the superficial region showing a higher value of lightness than the deep region of the RBC or HW lines (P , 0.001). The percentage of the superficial region in the pectoralis major muscle was higher in the HW line compared with the RBC line (46.2% v. 38.0%, P 5 0.017). There were no significant differences in the total fiber number in the superficial and deep regions between the two quail lines (P 5 0.718). The HW quail line showed a larger mean fiber cross-sectional area (CSA; 375.5 v. 176.6 mm 2 , P , 0.001) and type IIA fiber CSA (243.7 v. 131.9 mm 2 , P , 0.001) than the RBC quail line. The HW line also had greater CSA percentage (60.2% v. 34.2%, P , 0.001) and number percentage (41.6% v. 14.2%, P , 0.001) of type IIB fibers, although there were no significant differences in type IIB fiber CSA between the RBC and HW lines (P 5 0.219). Therefore, greater body and muscle weights of the HW line are caused by differences in muscle fiber characteristics, especially the proportion of type IIB fiber and the CSA of type IIA fiber, compared with the RBC line. The results of this study suggest that muscle fiber hypertrophy has more impact on body and muscle weights of the different quail lines than muscle fiber hyperplasia.

Comparison of Muscle Fiber and Meat Quality Characteristics in Different Japanese Quail Lines

“…For example, domestic pigs showed a larger area of muscle fibers and a higher percentage of type IIB fiber compared to wild pigs (Ruusunen and Puolanne, 2004). In broiler-type chickens harboring a greater muscle mass, the pectoralis major muscle is composed of type IIB fiber, and type I and IIA fibers are not found in the superficial region of the pectoralis major muscle (Choi et al, 2013). Cross-sectional area of type IIB fiber is generally larger, as the growth rate of type IIB fiber after birth is approximately two times greater compared to type I fiber (Oksbjerg et al, 1994).…”

“…In chicken, the fast growing line that has a greater muscle mass tended to exhibit a greater number (20%) and size (90%) of muscle fibers in the pectoralis major muscle compared to the slow growing line (Remignon et al, 1995). The heavy weight (HW) quail line selected for a higher body weight (BW) at 4 weeks after birth showed more than twice the area of muscle fiber at the pectoralis major muscle compared to the random bred control (RBC) line (Choi et al, 2013). …”

Skeletal Muscle Characterization of Japanese Quail Line Selectively Bred for Lower Body Weight as an Avian Model of Delayed Muscle Growth with Hypoplasia

“…At 42 and 75 d post-hatch, the area of pectoralis major muscle was measured at the diagonal line of a point 1/2 in the pectoralis major muscle [5], [12]. A significant difference was observed in the lightness value ( L * ) measured with a Minolta chromameter (CR-300, Minolta Camera Co., Japan) of the pectoralis major muscle between the superficial (away from the pectoralis minor muscle and bone) and deep (close to the pectoralis minor muscle and bone) regions at 42 and 75 d post-hatch [5].…”

“…With these advantages, several lines of quail have been developed by selection for body weight from the random bred control (RBC) Japanese quail for over 40 generations at The Ohio State University [3], [4]. Selection of quail led to establish a heavy weight (HW) quail line that exhibited more than two times greater pectoralis major muscle weight (PMW) than the RBC quail line, which is accompanied by muscle hypertrophy rather than muscle hyperplasia [5]. However, the selected line of quail for the low weight (LW) line has not yet been characterized for muscle growth and development.…”

“…Whereas, the pectoralis major muscle of the volant species, including quail, is more oxidative and composed of type IIA and IIB fibers due to their flight behavior [15]. The HW quail line exhibited a higher percentage of type IIB fibers compared to the RBC quail line [5].…”