ANSC356 - Chicken Breeding and Genetics

1) increased product output per bird
2) increased efficiency of production per unit feed
3) improved quality of the product

3 main goals of the commercial poultry industry

selective breeding

How are the 3 main goals of the commercial poultry industry achieved?

1) feed conversion efficiency
2) growth rate

2 most important traits for broilers

1) feed conversion efficiency

2) egg laying

2 most important traits for layers

pedigree

Breeding is based almost entirely in…

vertically integrated

poultry industry integration

one company owns everything

What does vertically integrated mean?

comb types

Bateson & Punnett demonstrated genetics in animal species using chicken what?

2004

When did the chicken genome get published?

epigenetics

Chickens are a popular species to study the effects of what?

epigenetics

study of the chemical modification of genes

1) Macrochromosomes
2) Microchromosomes

2 sets of chicken chromosomes

WZ

Hen genotype

ZZ

Rooster genotype

39

How many chromosomes are in chickens?

Single nucleotide polymorphisms (SNP)

type of point mutations

polygenic/quantitative traits

trait controlled by multiple genes

candidate loci

loci that may become of interest to breeders

1) feather color

2) comb shape
3) skin color
4) barring color
5) rate of feathering

6) sex linked dwarfism
7) some egg colors (brown)

7 chicken traits controlled by a few genes

1) growth rate
2) feed conversion ratio
3) breast muscle size
4) number of eggs per clutch
5) number of eggs per year

6) hardiness

6 chicken traits that are controlled by many genes

1) white feathers
2) yellow or white skin color
3) early feathering
4) no broodiness
5) highly variable

5 traits that make the “ideal” chicken

used to sex chicks

early feathering is used for what?

type

general shape or form of a chicken

breed

an established group possessing identical features

variety

subdivision of a breed

class

group of breeds developed in certain regions

white leghorn

egg layer breed produces white eggs

broilers

selection based on paternal and maternal breeds

cornish

broiler breed male

1) mutations

2) hybridization

3) heritage breeds

3 ways to increase genetic diversity

hybrid vigor (heterosis)

phenomenon that hybrid offspring outperform the average of their parents

heritage breed

breeds that existed prior to the modern industry

deleterious

Most mutations are said to be…

Cp locus (Creeper)

Recessive lethal allele causes short wings and legs in heterozygous chickens

1950s

What year does a breed have to have existed to be considered a “heritage” breed?

1) flock mating

2) pen mating

3) artificial insemination

3 methods of mating

1) Primary breeder

2) Multipliers/hatcheries

2 types of breeding centers

turkey

What bird must use artificial intelligence to replenish the industrial supply?