Samenvatting Animal Breeding and Genetics

Samenvatting
H2 en H4
Inbreeding
 Loss of genetic variation
Crossbreeding
 Hybrid vigour or heterosis
 Crossbred will do better than original


Production system
 Geographical location
 Purpose of animal
o Production
o Companion
o Sport
o Working
 Animal species and breed

Breeding objective
 Breeding goal
o Specific traits with their desired direction
o Define
 Determine
 Economical
 Non-economical
 How to weigh the traits into single criterion
 Breeding goal should be directed to the future

Economic value = Difference revenues – difference costs

How to include non-economic issues to breeding goal
 Desired gains

Information
 Need phenotypes
o How often
 Repeatability:
 how similar are subsequent measures on the same animal on
different times
 Reproducibility:
 How similar are measures on the same animal between different
persons/locations
 Need pedigree
 Can collect genotypes

Genetic marker: flag on the genome with known position and sequence

, Dissemination: verspreiding


Evaluation
 Selection response
 Inbreeding and genetic diversity
 Costs




H5
P=G+E
 Phenotype
 Genotype
 Environment
Genetic model specifies the genetic and non-genetic compounds of a trait

Difference between animals: variance
 Var (P) = var (G) + var (E)
 σ2

Difference between genetic and heritable
 only get half of father and half of mother
 dominance


Additive genetic effect
 breeding value
 average effect of alleles
 heritable component of G
Dominance effect
 the effect of an allele depends on the other allele at the same locus
 not inherited
Epistasis effect
 the effect of an allele depends on alleles at other loci
 not inherited

G = u(mean) + A + D + I

P=A+E


Heritability
 transmitting your trait to the offspring

calculate
 model
o x as: average of both parents
o Y as: average off spring