Original article Effect of embryo cryopreservation techniques on reproductive and growth traits in rabbits

Abstract- The combined effects of embryo recovery, embryo cryopreservation and embryo trans-fer techniques on growth and reproductive characters of rabbits were studied. The animals coming from cryopreserved embryos were penalized for individual average daily gain during the fattening period in 1.72 g/d (P < 0.05) when they were compared to animals born after natural matings and pregnan-cies. The difference disappeared when we analysed the same character in the progeny. The litter size class effects were linear for weaning and slaughter weight and non-linear for daily gain, pointing out the independence of this character with respect to maternal effects. There were no differences for litter size or kindling interval between the animals. Growth characters were affected by the season effects (706.8 versus 654.3 g in weaning weight and 1 940.6 versus 1 875.1 g in slaughter weight; spring versus summer, P < 0.05). Also, the reproductive characters had the lower value for litter size in summer and the higher kindling interval (52.3 versus 45.4 days; summer versus spring, P < 0.05). It is concluded that the experiments using cryopreserved animals should work with the progeny of those animals instead of with themselves, especially for growth characters, in order to avoid the possible negative effects observed. © Elsevier / Inra embryo / cryopreservation / reproduction / growth / rabbi