The Impact of Genetics on Poultry Production in China Ning YANG, Ph.D. Professor and Head Dept. of Animal Genetics and Breeding College of Animal Science and Technology China Agricultural University Beijing , CHINA

Facts of Poultry Production in China  Largest poultry population in the world: billion birds in stock plus slaughtered in 2005  Top egg producer in the world, million tons in 2005, representing 40% of world total production  Second largest poultry meat producer in the world  A kingdom of waterfowl, with over 70% ducks and 85% geese in the world

China is a domestication center of chicken and waterfowls, and has over 5000 yrs history of poultry production

Extensive genetic diversity of Chinese local chicken breeds

Chicken breeds in Jiangxi Ningdusanhuang Baier Dongxiangluke Yuganwugu SilkieLingkun ChongrenmaKangle

Significant Contribution of Chinese Native Chicken to the International Chicken Genome Project

2.8 million SNPs were identified in the chicken

Before 1980, the poultry production in China were mainly in the form of backyard farming, with vast diversity of native breeds and low production efficiency

The Age of Genetics In 1900, Redicovery of Gregor Mendel’s Genetic Principles Jay Lush: Founder of the Science of Animal Breeding

Genetics has changed world poultry industry Dr. Paul Siegel’s chicken lines have demonstrated the power of genetic selection

Great Changes for Broiler Carcass During Past 20 Years

Chicken meat providers in China  Broilers  Native chickens  color-feathered  slow-growing  Improved or unimproved  Spent hens ~2.5 billions >3 billions 1 billion

Broiler Chickens  Mainly produced in Northern China  Integrated production system  Breeder, feedmill and processing  Company plus household farms  Better service to farmers  Branded products  Export to Japan, Korea et al.

X ABCD X XX XX X x 125 x 45 GP, 600,000 PS, 25million CS,~ 3 billion Pipeline for Broiler Production in China Pure Lines in USA GGP

Major Players for Broiler Breeders in China  Aviangen  Arbor Acres  Ross  Cobb-Vantress  Avian  Cobb 500  Others  Hubbard  Indian River

In certain parts of the World, consumers have strong preference for quality chickens with:  Specific appearance (feather color, shanks, skin, comb, et al)  More tasty meat They are willing to pay higher price for the so-called quality chickens

Comparisons  Quality chickens  Developed from native chickens  Specific appearance  slow-growing (70~120d)  Poor FCR (2.1~3)  Tasty and chewy  Better disease resistance  Easy to manage  Higher production cost  Broilers  Fast growth rate (40d)  Better FCR (1.6)  More meat (Breast 20%)  Soft meat  Less flavor  Need good facility  Hard to manage  Reasonable cost

Examples for quality chickens Three-Yellow (3Y) in China  Yellow is a royal color in China  Yellow feather  Yellow skin  Yellow shank  Sold as live birds:  biosecurity risks  Developing Fast  Export to Hong Kong

Other examples  Other types of quality chickens partridge, black-boned, silkies

Comparisons of Breeding Objectives  Quality chickens  Appearance  Meat flavor  Breeder performance  Growth rate  FCR  More difficult to achieve  Broilers  Growth rate  FCR  Carcass composition  Livability  Breeder performance

Quality Traits Appearance so-called packaging traits  No unique pattern as consumers’ views vary  Color of plumage, skin or shank: yellow (buff), red, partridge, and black  Redness and size of comb  Sex maturity

Plumage colors

Does plumage color really matter? Yes!  Sold mainly in live-bird market.  Tradition No!  We need meat rather than feather.  No solid evidence that plumage color is associated with flavor

Genes for feather color Good News: Functional Genes have been identified PMEL17 for I, and TYR for C

Comb  Redness and size of comb are important indicators for sex maturity  Pullets reaching sexual maturity deposit sufficient intramuscular and subcutaneous fat, crucial for enhancing meat flavor  Pullets with bright red, upright and big comb are considered first-class quality chickens in China

Meat Flavor  Eating quality: both taste and odor  Content of fatty acids, amino acids, and nucleotides  Content of intramuscular and subcutaneous fat and lipids are crucial for enhancing meat flavor.  Determined by breeds and marketing age  The meat flavor can be enhanced by free range system

Meat Flavor  IMP: Inosine-5 ’ -monophosphate

IMP content of breast muscle in AA broilers and Beijing-you IMP content of leg muscle in AA chicken and Beijing-you

Meat Texture  Density and diameter of muscle fiber  Muscle fiber type

Muscle Fibers P F2F2F2F2 F2F2F2F2 WP Rock Silkie F2F2F2F2 F2F2F2F2

Genetic selection has also significantly changed the Laying Performance Egg Production Curve (1990 vs 2005)

Dominating Layer Breeders in China  Hyline ~ 40%  Hyline Brown  Hyline W36  Lohmann  Lohmann Brown  Others  ISA Brown  Hisex

1775bp DW dw Exon 5 Exon 6 Exon 7 Exon 8 Exon 9 Exon 10 Liver Cell  Dw gene was identified in 1959 (Hutt)  Main phenotypic effect: reduced growth and lower body weight, leading to better feed efficiency  dw gene has been cloned and identified as the deficiency of growth hormone receptor gene Application of sex-linked dwarf gene (dw)

Dwarf layers have been developed in China and extended widely as an efficient type of egg layers (FCR~2.05)

Hunting for Blue-eggshell Gene Gene O was positioned on Ch.1