Influence of inbreeding level on economic traits of imported rabbit populations in Egypt

Abstract

Influence ofinbreeding level on economic traits of 3 (5 075 records) imported rabbit breeds 2740 Bauscat, 1 739 New Zealand White and 596 Califomian after 7 years of importation, were analyzed by using 2 models. The 2 models included inbreeding coefficients (IC) of does as fixed effects or covariate. Inbreeding adversely affected litter size and mass at birth and weaning and pre-weaning mortality, while bunny weIght and pre"weaning daily gain unexpectedly were sign ificantly larger in >0.50% (IC) group than in the other groups studied. Linear regression coefficients of IC on pre-weaning traits were highly significant in the breeds studied. Inbreeding levels in imported populations can be avoided by combining inbreeding levels With selection to purge a population of the genes that cause inbreeding depression.