Proceedings of the New Zealand Society of Animal Production.
1986, 46: 105-110
Proceedings of the New Zealand Society of Animal Production.
1986, 46: 105-110
Selection objectives for dairy production concentrate upon milk production with recent attention to total solids content. For meat sheep, lamb production per ewe is important for competitive efficiency.
Number of lambs and maternal contribution to lamb survival and lamb growth during suckling are important for the suckling breeds in the South and the improved breeds in easier conditions in the North, the latter also receiving emphasis on later lamb growth and carcass quality.
Selection programmes are highly organised nationally under the data- processing control of INRA and the national co-ordination of ITOVIC. Twenty Breed Promotion Committees (UPRA's), 77 Professional Advisory Organisations (EDE's) and 11 Data Processing Associations (CRI's) are involved with a well-structured relationship among them.
Selection schemes use different tools to give emphasis to dissemination of genetic merit in addition to ranking animals for breeding worth.
The National Recording Scheme provides the common essential ingredient for all schemes. Animal information embraces natural oestrus or induced oestrus, litter size and live weight of lambs. Maternal pedigree is always recorded at birth while paternal pedigree is known if single-sire natural mating or AI is used. Electronic development is being introduced to assist automated collection of live weights and early provision of on-farm flock summaries.
AI is used to assist genetic improvement over about 200 000 ewes, mainly dairy breeds. It allows superior ewes to remain on farms - it is estimated that in this way Ai can increase genetic progress by up to 30%. AI also avoids the need for centralised progeny testing and assists the gene dissemination from superior rams. Nucleus flocks are promoted as centres of gene dissemination only for scarce breeds and for those with very small flock size.
Rearing of rams in a central location gives breeding schemes greater control over gene dissemination and organisation of elite matings, especially through AI. Considerable emphasis is given to this aspect of the French breeding programme to ensure effective gene flow for production of the next generation of sires.
Central testing stations are also used, mainly to evaluate young meat breed rams which are the progeny of elite matings for growth and carcass merit in a standard environment and as a baseline for live animal performance assessment.
Not all the schemes use the same tools in the same way. Breeder commitment and co-operation is nevertheless an important ingredient of the effectiveness in each case.
Keywords: NZSAPAB; France; sheep; recording schemes; genetic improvement; meat production; milk production; national organisations; data processing; artificial insemination
