Selecting litter size in rabbits: analysis of different strategies.

E. Armero, Manuel Baselga, J. Cifre

Abstract

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.


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References

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 Universitat Politècnica de València

 

Official journal of the World Rabbit Science Association (WRSA)

 

e-ISSN: 1989-8886     ISSN: 1257-5011   https://doi.org/10.4995/wrs