EFFECT OF RECIPIENT GENOTYPE ON SURVIVAL RATE AT BIRTH OF FROZEN LOCAL RABBIT EMBRYOS

Abstract

SUMMARY New Zeland White (NZW) and APRI rabbit strains were used as recipients to study the survival rate at birth of frozen APRI embryos as well as the effect of site of ovary on ovarian activity, ovulation and embryo recovery rates. A total of 18 APRI rabbits line were super-ovulated using PMSG and naturally mated with bucks of the same line. Embryos were collected 64–66 h post coitum and the normal one was examined morphologically before frozing in liquid nitrogen. After thawing, embryos (n=140) were transferred into the oviducts of recipient does of both APRI and NZW does (n=8 both). Results indicated that no significant effect of the site of ovary on ovulation rate. The percentage of ovulation and recovery rates were higher insignificantly in left ovary by 7 and 11% than right ovary, respectively. Average number of collected APRI embryos was 12.39 ± 0.83 and recovery rate 76.1 ± 16.2/doe. Examination of ovarian structure indicated that numbers of bleeding follicles, large follicle, and small follicles were 6.22±1.98, 9.89 ±2.13 and 9.56 ±2.38, respectively. Genotype influenced the pregnant rate being 75% in APRI vs. 50% in NZW as well as on survival rate, which was about 45% in APRI and 31.9% in NZW.