Genetic parameters of litter waight traits of apri rabbits in Egypt

الملخص EN

Litter Gain traits, (from birth till both, 21 and weaning age and from 21 days till weaning, at 35 days), for two consecutive years on APRI rabbits.

The data of Litter Gain traits (LG B-21; LGB-W and LG21-W) contained a total of 192 litters produced from 80 does pedigreed by 9 sires and 12 dams, were analyzed.

Heritabilities of the considered doe traits were relatively low being 0.14, 0.14 and 0.13 for Litter Gains (LG B-21; LGB-W and LG21-W); resp.

Furthermore, estimates of permanent litter effects were rather low being 0.0, 0.002 and 0.002 for Litter Gain at the same manner.

The ranges of the APRI does' transmitting ability (TA ± SE) for LG B-21; LGB-W and LG21-W were (0.67 ± 0.19, 0.340 ± 0.13 and 0.10 ± 0.12 g.) with the accuracies being 0.51, 0.46 and 0.45.

As for APRI dams' data transmitting ability (TA ± SE), the ranges for the same previous traits were 0.47 ± 0.22, 0.24 ± 015 and 0.07±0.14 g. Interestingly, and though of the larger numbers involved, ranges of accuracies estimates (rAP) of the predicted transmitting ability (TA) were mostly higher in the dams data set followed by those of does.

Furthermore, significant moderate spearman correlation estimates were obtained among various ages' BV of the studied traits of data does.

These estimates of correlation, however, were age dependent and decreased as age advance. In addition, estimated epigenetic trends (EP), for Litter Gain traits under study suggested that it is possible to achieve slow, but simultaneous improvement of litter traits with selection program in rabbits.

LG traits recorded generally a negative EP trend during the majority of the year-seasons effects under study.

As regard to EP with parities, the high LG response was postponed to the 1st.

parity