Effect of hormonal treatment on rabbits ovarians response, normal embryos production and in vitro embryo development post-thawing

Abstract: The effect of eCG dose injection on rabbits ovarian response, normal embryos production and in vitro survival of embryos after vitrification thawing were examined. Forty-one of multiparous New Zealand White (NZW) rabbits (12 month of age, 3.87±0.16 kg average body weight) were used as embryo donors, allotted in three groups. Does of the 1st group (n= 21) were injected intramuscularly with 20 μg GnRH/doe for induction of ovulation and artificial insemination (control). Embryo donors in the 2nd and 3rd groups (n= 10/group) were administered intramuscularly with 20 or 40 eCG IU/kg live weight (superovulation), 68 h before artificial insemination. Immediately prior to insemination, the does were injected intravenously with hCG at 40 IU/kg live weight. All does were slaughtered at 48-50 h after insemination. Embryos were recovered, counted and evaluated for their stage of development, morphological appearance then vitrified Post 48 h storage in liquid nitrogan (LN2) at -196 °C, embryos were thawed and cultured in vitro with Ham's F10 medium supplemented with 200% FCS for two days.
Results showed that donors treated with 20 or 40 IU eCG/kg live weight produced significantly (p<0.01) more CLs, haemorrhagic follicles and yielded three to four folds embryos/doe when compared with GnRH (control group). Embryos recovered from does treated with GnRH (control group) reflected a higher fertilization rate (96.6%) than those recovered from does treated with 20 (89.4%) or 40 (84.1%) IU eCG/kg live weight. The percentage of morphological normal embryos recovered from donors injected with 20 or 40 IU eCG/kg live weight (84.9 or 77.0%) was significantly (P<0.05) lower than that obtained from the normally ovulated does (97.4%). Donors treated with 40 IU eCG/kg live weight retard the rate of embryonic development and reduced their diameters more than those injected with 20 IU eCG/kg live weight compared to GnRH (control group).
In 40 IU eCG treated donors-vitrified embryos group, only 61 from 147 embryo vitrified-thaw reached blastocysts (41.5%), whereas 112/186 (60.2%) in 20 IU eCG treated does compared to 74/111 (66.7%) in control group. The present study demonstrates that doe rabbits treated with 20 IU eCG/kg live weight provides superior embryos survival rates than those
treated with 40 IU eCG/kg live weight for rabbit embryos production manipulation studies and gene bank.
Keywords: Hormonal Treatments, Ovarian Response, Rabbit Embryos, Vitrification.
Publication year 2013
Pages 37-46
Availability location معهد بحوث الانتاج الحيوانى-شارع نادى الصيد- الدقى- الجيزة
Availability number
Organization Name
serial title Journal of Production & Development
ISSN 1110-2643
Author(s) from ARC
Agris Categories Animal physiology - Reproduction
Rabbits. Vitrification.
Proposed Agrovoc Rabbit Embryos;Ovarian Response;Hormonal Treatments;
Publication Type Journal