Effect Of Crossbreeding On Some Productive Traits In Rabbits:

Mohamed El-amin Amer

3UM14ARYA crossbreeding experiment lasted for three consect1veproduction ye~~s 1976/1977 - 1978/79, inclUSive wasconducted on the rabbi1; flock raised at Dokkl ExperimentalStation belonging to tlle AnimalProduction Research Institute,Agriculture Research Genter} Ministry of Agriculture.This experiment was caJ:”r1edout using Bauscat, Giza White,White GiantFlander and Baladi Red rabbits with the aim ofstUdying the effect of crossbreeding in addition of those ofbreed group and someot.har factors on the main productivetraits involved in rab’bit raising. Other objective of thisstudy was to eva!uate heterosis, general and specific combiningabilities as well ELS maternal and reciprocal (sex-lickage)effects and their importance for litter traits and body weightof rabbits of the four breeds involved. Data analysed weretaken on 3254 rabbits born in 513 litters during the experimentalperiod. Results can be summarizedas follows:General AnalysisLitter size:Amongthe four purebred groups used in this stUdy,Giza White (G) rabbits ranked the first for litter size atbirth and at weaninS; wnile amonGthe twelve crossbred groupsobtained, 3auscat-Baladi Red (BR) crossbred litters were the~.” .. -.-219best performing at both ages. Differences in litter sizedue to breed group effec~ts were not s1gn1f103.0.teither atbirth or at weaning.Crossbreeding was generally associated with theimprovementin litter s:Lzeat birth and at weaning. Differencesbetween reciprocal crosses indicate that maternal andsex-linkage effects on litter size at birth and at weaningwere limited and non-significant.Litter size at birth and at weaning differed insignificantlywith year of production. Litter size at both agesvaried but not consideri~bly with month of kindling, the differenceswere not sign~~icant at birth but significant(p..c:::... 0.05) at weaning. The largest size was seor-ed bylitters born during Janua.I’Y” - February month interval.Litter size Lncr-e aaed, in gener al, , as parity advancedat birth but did. not show any consistent trend at weaning.Differences due to pari”::;yeffects failed to prove significantat both ages.The advance of age of doe caused the decrease of littersize at birth and its iacrease at weaniog, but with neitherconsiderable nore significant differences at both ages.