Recent advances in breeding for quality chickens.

摘要

White-feathered broilers dominate world poultry meat production owing to their rapid growth and high feed efficiency. However, consumers' preference for colour-feathered and slow-growing meat-type quality chickens is growing in certain regions of the world. Among them, the 'Three Yellow' of China and 'Label Rouge' in France are two famous examples. The appearance (plumage, skin, combs and so on), meat flavour, and meat texture are the main attributes that attract customers to purchase them. For practical breeding, quality chickens were initially produced by direct use of native chicken breeds, which are generally slowly-growing with poor feed conversion. Currently, the breeding for quality chickens in China is characterized with crossbreeding between native breeds and highly-selected lines with rapid growth rate or relatively high egg production. The breeding objectives focus on improving growth rate and reproductive efficiency while maintaining original appearance characters of native chicken such as plumage colour, body shape, comb shape, skin and shank colour and so on. The performances of native chickens have been greatly improved by crossbreeding. Two-way or three-way crossing is commonly used in producing commercial quality chickens in China. In some cases, the dw gene has been introduced into maternal line for better reproduction efficiency and lower feed cost. For future development, breeders and producers will place more and more breeding significance on meat quality traits, which include meat flavour, tenderness, fat deposition, muscle fibre composition, visual characters and so on. As evaluation of these traits is expensive and time-consuming, new molecular markers will play more important roles. Once reliable markers are identified, early marker assisted selection can be performed with great selection accuracy and without slaughtering. Attempts to identify candidate genes related to meat flavour, muscle fibre, lipid metabolism and other physical characters have brought great potentials for future breeding of quality chickens..