Resumen de Effects of different doses of PMSG on ovarian response and in vitro embryo development in rabbits

G. Stradaioli, A. Verini Supplizi, M. Monaci, C. Canali, C. Boiti

• The aim of the study was to compare ovarían response, embryo recovery rate and in vitro embryo growth in New Zealand White rabbits injected with different doses of PMSG. On day-26 post partum 39 primiparous non-lactating does were given i.m. the following treatments: Group 1 (n=13) 0.1 mi distilled water; Group 11 (n=13) 20 IU PMSG; Group 111 (n=13) 100 IU PMSG. Seventy-two hours later the animals received 0.8 µg GnRH and were artificially inseminated. Forty-eight hours after insemination, the does were sacrificad and the genital tracts were removed and kept in Dulbecco's Phosphate Buffer Salina. Ovaries were weighed and normal anovulated follicles >1 mm (AF), haemorrhagic follicles (HF) and fresh corpora lutea (CL) were recordad. The oviducts were flushed with TCM199 and embryos were morphologically evaluated. The zygotes were placed in TCM199 + 5% Foetal Calf Serum and culturad in vitro in a humidified incubator at 390C with 5% C02 in air. Embryo development was appraised after 24, 48 and 72 hours. Ovarian weights were not affected by treatments and there was no difference in the total number of AF+HF+CL among groups (Group 1 = 56.7 ± 6.2, Group 11 = 57.0 ± 7.1 and Group 111 = 56.6 ± 6.7). PMSG significantly increased the number of HFs (P<0.01) as they were nearly double in Group 11 (9.3 ± 3.5) and four times as many in Group 111 (17.8 ± 3.3) comparad with the control (4.3 ± 3.1). Embryo recovery rate was not influenced by treatment. In vitro embryo development rata was significantly lower (P<0.001) in the PMSG groups (Group 11 = 74.7% and Group 111 = 72.4% vs Group 1 = 93.2%)