Effect of Breed and Parity on Growth Performance, Litter Size, Litter Weight, Conception Rate and Semen Characteristics of Med

This study aimed to investigate the differences among four medium breeds of rabbits (Rex, New Zealand White, California and Baladi Red) in productive performance and semen characteristics. Hundred twenty does, 7–9 months of age and 3–3.5 kg body weight from Rex, NZW, California, and Baladi Red. The numbers of 360 parities were analyzed to evaluate breeds effects. Traits studed were litter size and litter weight at birth, at14 days and at weaning. Mortality percentage from birth to weaning was calculated. Also, the analysis concerned 5120 ejaculates from 80 bucks from the 4 breeds of rabbits. The recorded traits were: pH, ejaculate volume, sperm motility, concentration, total number of spermatozoa per ejaculate, percentage of sperm normalcy and percentage of sperm abnormalities. The volume of each ejaculate was registered and an aliquot was separated for further analyses. Breed effect led to significant (P≤ 0.05) effect on litter size and litter weight at birth, 14 days and at weaning. Parities had significant (P≤ 0.05) effect on litter size and on litter weight at birth, 14 days and at weaning. California does recorded largest litter size and heaves litter weight at birth, at 14 days and at weaning. California does recorded significant higher conception rate (%), lower number of services per conception and lower mortality rate compared to the other breeds. Mean values of total ejaculate didn't differ (P>0.05) among breeds. California Bucks tended to have larger ejaculate volume, higher motility percentage, lower abnormal percentage and higher total live sperm compared to the other breeds. Key Word: Rabbits breed, parity, birth and weaning traits, semen characteristics, in hot climates.