Four-year crossbreeding project involving Spanish maternal line called V-line (V) and Saudi Gabali (G) rabbits was carried out to produce six genetic groups of V, G, ½V½G, ½G½V, ¾V¼G and ¾G¼V. Interse matings for genetic groups of ½V½G, ½G½V, ¾V¼G and ¾G¼V were also practiced. Milk yields (MY) at intervals of 0-7 days (MY7), 7-21 days (MY21), 21-28 days (MY28), and 0-28 days (TMY) and milk components (MC) at 14 days of lactation (fat, protein, lactose, ash, and total solids), and milk conversion ratio (kg of litter gain per kg of milk suckled, MCR) were evaluated for 2540 litters of 854 does fathered by 142 sires and mothered by 351 dams. A repeatability animal model was used to estimate linear contrasts and expectations of solutions for the effect of doe genetic groups and to derive the estimate of direct (GI) and maternal (GM) additive effects, direct heterosis (HI), maternal heterosis (HM) and direct recombination effect (RI) for different traits under the study. Heritabilities for MY traits and MCR were moderate and ranging from 0.18 to 0.27, while they were low or moderate and ranging from 0.09 to 0.28 for MC. The positive estimates of GI for MY (5.8-12.6%) and MC (4.0-17.7%) and the negative estimate for MCR (-18.3%) were significantly high and in favour of V-line does. GM were in favour of V-line dams; being 222 g, 0.67%, 0.63%, and –0.08 for MY21, total solids in milk, fat in milk, and MCR, respectively. All estimates of HI for MY and MC were positive and most of them were significant ranging from 9.7 to 22.7 % for MY traits (P |
