Selecting litter size in rabbits: analysis of different strategies.

E. Armero, Manuel Baselga, J. Cifre


A Family lndex and a reduced BLUP using records of two generations, have been comparad with a BLUP under a repeatability animal modal that usad ali records (complete BLUP). An analysis of robustness of the methods to changas in genetic parameters was also carried out and four types of assortative mating were comparad with random mating through the ratio of expected responses per unit of time. Records of 18 and 14 generations of two lines of rabbits selected for litter size at weaning were usad, and the selection process was studied in generation 17, 18 of one line, and 13, 14 of the other. The two simplified methods were practically the sama in our study with non overlapping generations and good balance between animals to be selected and fixed effects. Toe correlations between rankings and between genetic evaluations of matings or individuals of a simplified method and the BLUP using all records ranged between 0.65 and 0.98. The coincidence ratio of selecled matings is between 0.62 and 0.94, and the response loss ratio between O and 0.17, being the average around 0.05 and 0.06. The methods of selection revealed themselves as very robust. Finally, it was concluded that the only type of assortative mating that increased the response in relat1on to the random mating was the one carried out early in the process of selection to obtain females, being the range of the ratio of responses per unit of time 1.067-1. 197.

Full Text:



BASELGA M., BLASCO A., ESTANY J., 1984. Indice de selección de caracteres reproductivos con información variable. III World Rabbit Congress, vol. 1, 62-65.

BASELGA M., BLASCO A., ESTANY J., 1985. Evolución de Reproductores. 11 Posibilidades de simplificación de los métodos de selección. I Jornadas sobre Producción Animal. ITEA, vol. extra n°5, 41-52.

BASELGA M., GÓMEZ E.A., CIFRE J., CAMACHO J., 1992. Genetic diversity of litter size between parities in rabbits. J. Appl. Rabbit Res., 15, 198- 205.

CAMPO J.L., GARCÍA GIL M., 1994. Toe effects of assortative mating on the genetic change due to linear index selection in Tribolium. J. Anim. Breed. Genet., 111, 213-219.

CARABAÑO M.J., ALENDA R., 1990. Serving several species with animal models. 4th World Congr. Genet. App. Livestock Prod., vol. XIII, 394-399.

CASEY D., RATHJE T.A., JOHNSON R.K., 1994. Response to ten generations of index selection for components of litter size in swine. 5th World Congr. Genet. App. Livestock Prod., vol.XVII, 315-318.

DELANGE A.D, 1974. A simulation study of the effects of assortative mating on the response to selection. 1st World Congr. Genet. App. Livestock Prod., vol.111, 421-425.

ESTANY J., 1987. Metodología de la selección en líneas de reproducción y crecimiento de conejo de carne. ETSIA. Universidad Politécnica de Valencia. Doctoral Thesis.

ESTANY J., BASELGA M., BLASCO A., CAMACHO J., 1989. Mixed model methodology for the estimation of genetic response to selection in litters size of rabbits. Livest. Prod. Sci, 21, 67-76.

GARCÍA F., BASELGA M., BLASCO M., DELTORO J., 1982. Genetic analysis of some reproductive traits in meat rabbits. l. Numeric traits. 2nd World Congr. Genet. App. Livestock Prod., vol. VII, 557-562.

GÓMEZ E.A., 1994. La selección del tamaño de camada en el conejo de carne : influencia de los efectos matemos y de la heterogeneidad genética entre partos. ETSIA. Universidad Politécnica de Valencia. Doctoral Thesis.

HENDERSON C.R., 1975. Use of all relatives in intraherd prediction of breeding values and producing abilities. J. Dairy Sci., 58, 1910-1916.

LAMBERSON W.R., JOHSON R.K., ZIMMERMAN D.R., LONG T.E., 1991. Direct responses to selection for increased litter size, decreased age at puberty, or random selection following selection for ovulation rate in swine. J. Anim. Sci., 69, 3129-3143.

MATHERON G., ROlNIER R., 1977. Optimisation du progres génétique sur la prolificité chez le lapin. Ann. Génét. Sél. Anim., 9(3), 393-405.

MCBRIDE G., ROBERTSON A., 1963. Selection using assortative mating in Drosophila melanogaster. Genet. Res., 4, 356-369.

POUJARDIEU B., ROlNIER R., 1972. Optimization du plan d'accouplement dans la sélection combinée. Ann. Génét. Sél. Anim., 3, 509-519.

QUAAS R.L., 1984. Linear Prediction. Blup School Handbook. Anim. Genet. Proced. Unit., University of New England, Australia.

ROCHAMBEAU H. DE, BOLET G., TUDELA F., 1994. Long term selection. Comparison of two rabbit strains. 5th World Congr. Genet. App. Livestock Prod., vol. XIX, 257-260.

SALES J., HILL WG., 1976. Effect of sampling errors on efficiency of selection indices. 1. Use of information from relatives for single trait improvement. Anim. Prod., 22, 1-17.

WILSON S.P., KYLE W.H., BELL A.E., 1965. Toe effects of mating system and selection on pupa weight in Tribolium. Genet. Res., 6, 341-351.

WILSON S.P., BLAIR P.V., KYLE W.H., BELL A.E., 1968. Toe influence of selection and mating systems on larval weight in Tribolium. J. Hered., 59, 313-317.

Abstract Views

Metrics Loading ...

Metrics powered by PLOS ALM


 Universitat Politècnica de València


Official journal of the World Rabbit Science Association (WRSA)


e-ISSN: 1989-8886     ISSN: 1257-5011