Yi Ding;Ren-bo;Chang Su;Dan Hao;}$ Hu$^{;Yaodong;Jianrong Shi;Rui Rui;Weibo Xie;Hong Wang;Lijuan Lijuan;Peng Gao;Shuwe

yorkshire pig;erhualian pig;muscle fiber;age;longissimus dorsi muscle;thigh muscl

[Objective] To compare the muscle fiber growth between F1 generations of large Yorkshire pig and Erhualian pig by reciprocal cross, and provide a theoretical basis for the integrated breeding of meat quality traits and growth performances by rational utilization of hybrid combination. [Method] The hybrid pigs of large Yorkshire pig and Erhualian pig were fed and managed in the same conditions. The reciprocal combinations were Erhualian pig ♀ × Yorkshire pig ♂ and Yorkshire pig ♀ × Erhualian pig ♂, respectively. At the age of 20, 70, 120 and 180 d, the longissimus dorsi muscle and thigh muscle were collected and made into frozen sections for hematoxylin and eosin (HE) staining, and then the muscle fiber area was determined. [Result] The muscle fiber was thickened gradually with increasing age; and the absolute growth curve of muscle fiber area was presented as S shape. The diameter, perimeter and area of longissimus dorsi muscle and thigh muscle fibers in the reciprocal combination of Yorkshire pig ♀ × Erhualian pig ♂ were higher than those in the reciprocal combination of Erhualian pig ♀ × Yorkshire pig ♂(P 0.01). The thigh muscle grew faster than longissimus dorsi muscle at the age of 20-120 d; but at the age of 120-180 d, the growth rate of longissimus dorsi muscle was higher than that of thigh muscle; and at the age of 180 d, the muscle fiber area had no significant difference between the longissimus dorsi muscle and the thigh muscle. The muscle fiber area had extremely significant difference between the reciprocal combinations at the age of 20 d; but no significant difference was found at the age of 180 d. [Conclusion] The reciprocal combinations can affect the muscle fiber growth of hybrid pigs of Yorkshire pig and Erhualian pig, but the affect degree reduces with the increasing age.