Swine Production Lecture 12 - Mating

pure breeding

crossbreeding

types of breeding systems

purebreeding

eligible for breed registration, lineage, line purity and promotion

necessary to maintain genetic diversity and progress

crossbreeding

mating of animals of different breeds, aims to capture additive/nonadditive gene action

additive gene action

occurs when each gene has an expressed phenotypic effect

offspring exhibit phenotype that is the average of the parent's

nonadditive gene action

offspring traits differ from average of parent's

heterosis present

individual heterosis

how much hybrid vigor is in the offspring

increased performance traits due to crossbreeding

maternal heterosis

increased performance in sows and progeny from crossbred dam

increased litter size and rebreeding rates

paternal heterosis

increased performance in boars and progeny from crossbred sire

increased libido, breeding, and longevity

2 breed terminal cross

100% heterosis

3 breed terminal cross

maintain 100% heterosis

2 breed rotational cross

- Mate straight-bred sires of 2 different breeds to dams that are a mix of the two breeds

- Female progeny from one group transferred to the other group. All crossbred males are sold

3 breed rotational cross

- Three different sire breeds are mated to females that are a mixture of the three breeds

- Crossbred dams are mated with the breed of sire to which they are least related.