The major objective of pure pig breeding is to identify and propagate superior genes for use in commercial production primarily in crossbreeding programs as well as to propagate and identify superior females for maintaining valuable genetic material. Furthermore crossbreeding will not be worthwhile unless superior pure bred individuals are used.
Mating individuals of the same breed but who are less closely related than the average of the breed. There should not be a common ancestor for at least four generation back in the pedigree of the boar and the females with which he is mated. It is useful mating system in purebred individuals.
Mating between individuals of the same breed but which are more closely related than the average breed. This could be between as close individuals as full sibs or sire-daughter, mother-son. Pure breeding is a special kind of in-breeding. The effect of in-breeding is the concentration of common genes in the offspring. This high frequency of homozygous gene pairs applies to both desirable and undesirable traits. Many undesirable traits e.g hernia and cryptorchidism involve recessive genes thus inbreeding perpetuates their expression phenotypically. In breeding causes decrease in litter size and increases mortality. Inbred sows are inferior in milking and mothering ability. It delays sexual maturity in gilts and boars. Inbred boars have less sexual libido. In bred gilts have fewer eggs during oestrus and farrow smaller litters than those out bred.
PURE PIG BREEDING: Effects of in-breeding
- Sow with newly borne litters about 12 piglets
- Male and female piglets taken by another farmers to his home
- Breeding between the same siblings
- Female giving birth about 9 piglets
- About 25% less no of smaller and weak piglets are born as compared with first sow and some of them were born dead
- Male and female piglet taken by another farmers to his home
- Breeding between the same siblings about six piglets
- About 50% less no of very smaller and weak piglets born as compared with the first sow, some of them were born dead.
Breeding between full sibling = Less and smaller piglets born
PURE PIG BREEDING: Cross-Breeding
Mating two individuals from different breeds thus introducing into the progeny a gene combination that is different from that excising in either parent or in the breed of either parent. Cross breeding can involve two or more breeds, depending on the desired result. The sole purpose of cross-breeding is to take advantage of the observed improvement in performance of the progeny above that of either parent hybrid vigor or heterosis.
PURE PIG BREEDING: Methods of cross breeding:
- Cross breeding between unidentified breeds
- Cross breeding between identified breeds
Effects of cross breeding;
- Local sow with her piglets
- Exotic sow with her piglets
- Female piglet from local sow and male piglet from exotic sow are taken by a farmer to his home for breeding purposes
- Very healthy, strong, active and fast growing piglets are born