Reproduction in Domestic Animals

382 B Leboeuf, JA Delgadillo, E Manfredi, A Piace` re, V Cle´ment, P Martin, M Pellicer, P Boue´, and R de Cremouxmilking ability and mastitis, measured as CMT scores orSCC, are low according to Montaldo and Martinez-Lozano (1993) and Ilahi (1999). Genetic correlationsbetween milking ability and udder health remainunknown in goats.Contribution of AI to Genetic ImprovementProgrammes: The French Selection ProgrammeProduction from French goats, as measured by milkrecording on more than 100 000 animals in each breed,is on average 800 kg of milk for a lactation length of270 days. Fat and PC are higher in the Alpine than inthe Saanen breed: 3.7% and 3.2%, respectively, vs 3.5%and 3.1%. These results have been obtained afterapproximately 20 years of genetic improvement, with aselection scheme based on the use of AI.Determination of the selection objectivesThe objectives of the selection programme are revisedperiodically in order to adapt the genetic goals tomarket demands, and to take into account the genetictrends of the populations under selection (Piace` re et al.2002). Since 1970, the objective of the French programmewas the improvement of PY and PC withselection thresholds defined for each trait. However, asproduction traits are either negatively or positivelycorrelated, threshold selection on several traits is notefficient. Thus, in 1995, the former independent levels ofselection were replaced by a single selection thresholddetermined for a combined index ICC = PY + 0.4 PC(Piace` re et al. 1997). Selection pressure on proteinresulted in positive trends for protein and for fat content(FC) because of the positive correlation between bothtraits. However, gains on PC were higher than those forFC, thus inducing a slight negative trend in the ratioFC ⁄ PC. In 1999, the ICC was modified to stabilize theFC ⁄ PC ratio, by giving a slight positive weighting to fatyield and FC. As Alpine and Saanen goats have similarmatter yields, the production selection objective was thesame for both breeds.The same procedure was undertaken for type indicesto determine a single type objective. The type combinedindex, named IMC (Index Morphologique Caprin, goattype index) (Cle´ment et al. 2006) combines most relevanttype indices for breeders: udder profile (UP), udderfloor (UF) position, rear udder (RU) attachment andrear udder shape (RS). These four traits are responsiblefor 80% of the whole udder variability. However, typephenotypic and genetic differences between Alpine andSaanen goats were observed. So the IMC was not thesame for both breeds:Alpine IMC ¼ 1:5 UP þ UF þ RU þ RS;Saanen IMC ¼ UP þ UF þ RU þ 0:5 RSAs breeders wanted to obtain genetic progress for uddertype, as well as improving the milk production, they hadto define the respective weightings for both criteria in aglobal combined index. According to the geneticparameters of different traits, which were slightlydifferent according to the breed, they finally decided togive a weight of 44% and 33% on type in the Saanenand Alpine breeds, respectively.Technical structures and general organizationSelection programmes for dairy ruminants benefit fromthe cooperative action of farmers, milk plants, AIcentres and milk recording organizations, with thetechnical and scientific support of specialized institutions.The breeding law specifies the missions of eachorganization participating to the selection programme.There are seven organizations concerned with thebreeding of dairy goats:1. The EDE (Regional Breeding Bureaux) monitorsanimal identification. According to the Europeanrules, all French goats are officially identified with eartags and registered in a national database;2. France Controˆ le Laitier is responsible for milkrecording and providing technical advice to breederson breeding and feeding. Selection on productiontraits needs exhaustive records. In France, 340 000goats in 2200 herds are officially milk recorded andany breeder can access the milk recording services.Records are registered in a national database;3. The Centres Re´gionaux Informatiques (CRI,Regional Computing Centers) are responsible forthe regional databases and all regional data are thencentralized in a national database: Le Centre deTraitement de l’Information Ge´ne´tique (CTIG,National Computing Center for Genetics);4. Capri-IA is the national semen production centreand the national union of AI cooperatives for goats.Capri-IA produces frozen semen, which is sent to AIcooperatives responsible for on-farm inseminations;5. The Institut de l’Elevage (IE, Breeding Institute)gives technical support and coordinates data collection,validation and storage in the national database;6. The Institut National de la Recherche Agronomique(INRA) gives scientific support for the definitionof selection objectives, the genetic evaluation (indexcalculation) and the design of the selection programme;7. Caprige` ne France is the goat breeders association.It groups 800 breeders and 160 000 Alpine andSaanen goats. The Caprige` ne committee gathersrepresentatives of breeders, cheese producers, milkplants, Ministry of Agriculture and the technicalorganizations previously described. It is in charge ofthe general management of the selection programmeand the committee determines the selection objectives.Furthermore, Caprige` ne is responsible for the typerecording and the pedigree file management.Genetic evaluation of animalsThe statistical method used for genetic evaluation is aBLUP applied to an animal model. The advantage ofthis approach is that it provides unbiased breedingvalues: first, all available information is taken intoaccount and second, it allows the dissociation of geneticand environmental effects. However, to separate part ofthe variance as a result of genetic effects from those ofÓ 2008 The Authors. Journal compilation Ó 2008 Blackwell Verlag