AGB 211: Livestock and Poultry Breeding (2+1)

Genetic effect of inbreeding

GENETIC EFFECTS OF INBREEDING

Inbreeding makes more pairs of genes in the population homozygous irrespective of the type of gene action involved. The consequences of homozygosity are:

• Inbreeding does not increased the number of recessive alleles in a population; but merely brings to light through increased homozygosity.
• Inbreeding fixes characters in an inbred population through increased homozygosity whether the effects are favorable or unfavorable.
• As a result of homozygosity, the offsprings of inbred parents are more likely to receive the same genes from their parents than of offspring of non-inbred parents. This is another way of saying that inbred parents are more likely to be pre-potent than non-inbred parents.
• If overdominance exists (Aa is superior than AA or aa), inbreeding decreases the overdominance by changing the Aa genotype to AA and aa.