EFFECTS OF DIFFERENT DOSES OF PMSG ON OVARIAN RESPONSE AND IN VITRO EMBRYO DEVELOPMENT IN RABBITS

[EN] 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 JU 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 39•c with 5% C02 in air. Embryo development was appraised after 24, 48 and 72 hours. Ovarían 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%).[FR] Le but de cette étude est de comparar l'effet de p/usieurs doses de PMSG injectées a des lapines de race Néo-zélandais Blanc, sur la réponse ovarienne, le taux d'embryons récupérés et /eur croissance in vitro. Trente neuf lapines primipares, non allaitantes, ont regu le 2~me jour post partum une injection intramusculaire du traitement suivant: Lot 1 (n=13) O, 1 mi d'eau distillée; Lot 2 (n=13): 20 Uf de PMSG; Lot 3 (n=13): 100 U/ de PMSG. Soixante douze heures apres, les lapines ont regu 0,8 μg de GnRH et ont été artificiellement inséminées. Les lapines ont été sacrifiées 48 heures apres l'insémination ; le tractus génital pré/evé a été conservé dans la solution tampon phosphato-sa/ine de Dulbecco. Les ovaires ont été pesés et les follicu/es normaux non ovulés > 1mm (AF), les fo/Jicules hémorragiques (HF) et les corps jaunes ont été comptés. Les oviductes ont été lavés avec du TCM199 et on a évalué la morpho/ogie des embryons. Les zygotes ont été placés dans TCM199 + 5 % de sérum de veau et cultivés in vitro dans un incubateur humide a 39'C dans une atmospheres contenant 5 % de C02. Apres 24, 48 et 72 heures, on a estimé le développement embryonnaire. Les traitements n'ont pas affecté le poids des ovaires et le nombre total de AF+HF+CL n 'est pas différent se/on les lots (Lot 1 : 56, 7 ± 6,2 ;· Lot 2 : 57,0 ± 7, 1; Lot 3: 56,6 ± 6,7). Le PMSG accroft signíficativement le nombre de fo/Jicules hémorragiques (P