The Impact of Genetics on Poultry Production in China
Ning YANG, Ph.D.
Professor and HeadDept. of Animal Genetics and BreedingCollege of Animal Science and TechnologyChina Agricultural University
Beijing 100094, CHINA
Facts of Poultry Production in China
Largest poultry population in the world: 15.198 billion birds in stock plus slaughtered in 2005
Top egg producer in the world, 28.795 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 JiangxiChicken breeds in Jiangxi
Ningdusanhuang
Baier
DongxianglukeYuganwugu
SilkieLingkun
ChongrenmaKangle
Significant Contribution of Chinese Native Chicken Significant Contribution of Chinese Native Chicken to the International Chicken Genome Projectto 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
1985
2005
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 systemBreeder, feedmill and processing Company plus household farmsBetter service to farmersBranded productsExport to Japan, Korea et al.
X
A B C D
X X X
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 AcresRoss
Cobb-VantressAvian Cobb 500
OthersHubbard 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 colorTable 1: genotypes of white-feathered chicken
types genotypes notes
Domonant white IICCOOPPAA White leghorn
Recessive white iiccOOPPAA
Recessive white iiCCooPPAA
Recessive white iiCCOOppAA Recessive epistatic pp gene
Recessive white iiCCooPPaa
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:
00. 51
1. 52
2. 53
3. 54
4. 55
mg/ g
breeds
I MP
Inosine-5’-monophosphate
0
0. 5
1
1. 5
2
2. 5
3
I MP(mg/ g)
28 56 90
days
AABei j i ng- you
1. 7
1. 751. 8
1. 851. 9
1. 952
2. 05
I MP(mg/ g)
28 56 90
days
AABei j i ng- you
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
PP
FF22 FF22
WP RockWP Rock SilkieSilkie
FF22 FF22
China continues 21th year as top eggproducing country in the world
0
500
1000
1500
2000
2500
3000
3500
1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004
年份
()
总产
量吨
Al l eggsChi cken eggs
Genetic selection has also significantly changed the Laying Performance
Egg Production Curve (1990 vs 2005)
Dominating Layer Breeders in China
Hyline ~ 40%Hyline BrownHyline W36
LohmannLohmann Brown
OthersISA Brown Hisex
1775bp1775bp
DWDW
dwdw
Exon 5Exon 5 Exon 6Exon 6 Exon 7Exon 7 Exon 8Exon 8 Exon 9Exon 9 Exon 10Exon 10
Liver Cell
Dw gene was identified in 1959 (Hutt)Dw gene was identified in 1959 (Hutt)
Main phenotypic effect: reduced growth and lower body Main phenotypic effect: reduced growth and lower body weight, leading to better feed efficiencyweight, leading to better feed efficiency
dwdw gene has been cloned and identified as the deficiency of gene has been cloned and identified as the deficiency of growth hormone receptor genegrowth hormone receptor gene
Application of sex-linked dwarf gene Application of sex-linked dwarf gene ((dwdw))
Dwarf layers have been developed in China and extended widely as an efficient type of egg layers (FCR~2.05)
Thank you !Thank you !
Hunting for Blue-eggshell Gene
• Gene O was positioned on Ch.1
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