GENETIC PARAMETERS FOR MEAT PRODUCTION IN RABBITS. 1 - NON CARCASS COMPONENTS.

Abstract

Data of 122 males rabbits, randomly sampled from 19 sires of New Zealand White breed raised on two farms in Sharkia Governorate, Egypt, were analysed to provide estimates of heritabilities for non carcass components and to obtain estimates of genetic and phenotypic correlations among these components. AII rabbits were slaughtered when reached a live body weight of approximately 2 kg. The weights of non carcass components and hot carcass were recorded and dressing percentages were also calculated. Least squares analysis of variance showed that weights of rabbit non carcass components were more influenced by the effect of farm adjusted to the effect of slaughter weight, whereas they were slightly influenced by the effect of sires within farm. Generally, the heritability estimates for gastrointestinal tract and its components except stomach (h2 = 0.24) were high, ranged between 0.40 to 0.60 and were very high for trachea (h2 = 0.78), testes (h2 = 0.94) and kidney fat (h2 = 0.94) whereas the weights of urinary bladder, head, ears, pituitary gland, kidneys and lungs were moderately heritable, ranged from 0.21 to 0.39. The remaining traits showed low heritability estimates ranged between 0.02 and 0.14. Estimates of genetic and phenotypic correlations were high only between the weights of liver, testes and kidney fat and the weights of the other traits. Results suggested the possibility of improvement liver, testes or kidney fat weights by direct selection.