Determination of porcine plasma follitropin levels during superovulation treatment in cows

in Theriogenology (1988), 30(2), 379-386

Porcine follicle stimulating hormone (pFSH) and porcine luteinizing hormone (pLH), are widely used to induce superovulation in cows. An advantage of this treatment is that the LH:FSH ratio can be varied ... [more ▼]

Porcine follicle stimulating hormone (pFSH) and porcine luteinizing hormone (pLH), are widely used to induce superovulation in cows. An advantage of this treatment is that the LH:FSH ratio can be varied to optimize the growth of the ovarian follicles. However, due to the relatively short half-life of FSH, the superovulatory treatment requires numerous injections. A performant radioimmunoassay system (sensitivity=0.2 ng/ml plasma) was used to determine plasma pFSH levels in cows that were superovulated with 2 daily injections of 4 Armour Units (A.U.) of pFSH for 4 d. From plasma profiles, the half-life and the disappearance of pFSH were estimated at 5 h and at 10 to 12 h, respectively, confirming the necessity of using two daily injections. [less ▲]

Obtention de blastocystes après maturation et fécondation in vitro d'ovocytes de bovin: premiers résultats

in Annales de Médecine Vétérinaire (1988), 132

74.4% of two cells cow embryos are following in vitro maturation and fertilisation. Some embryos developed in rabbit's oviducts to morula and blastocyst stages. They wer frozen and thawed before transfer ... [more ▼]

74.4% of two cells cow embryos are following in vitro maturation and fertilisation. Some embryos developed in rabbit's oviducts to morula and blastocyst stages. They wer frozen and thawed before transfer in receptors. [less ▲]

Fast freezing of cow embryos in French straws with an automatic program.

in Theriogenology (1982), 18(3), 325-332

Cow embryos between day 6.5 and 9 were frozen in 1.5M DMSO in PBS at 2 degrees C/min from seeding to -25 degrees C before being plunged into liquid nitrogen directly or after 10 min at -25 degrees C ... [more ▼]

Cow embryos between day 6.5 and 9 were frozen in 1.5M DMSO in PBS at 2 degrees C/min from seeding to -25 degrees C before being plunged into liquid nitrogen directly or after 10 min at -25 degrees C. Cooling rate from 20 degrees C to -5 degrees C was 9 degrees C/min. Seeding was induced automatically at -5 degrees C by injection of liquid nitrogen vapour. Embryos were subsequently thawed by direct transfer to water at 20 degrees C (group I) or at 37 degrees C (group II). Survival was assessed by culture in vitro and by transfer. In group I, 35.7% were degenerated after thawing (compared to 35.4% in group II). Survival rate after culture in vitro for 24h was not significantly different (48.3% vs 42.8%) and hatching rate after 96h culture was quite similar (33.3% vs 34.4%). In group II, four pregnancies were obtained from 10 embryos transferred. Time at -25 degrees C did not improve the results. Automatic seeding did not impair survival. These results show that the quality of the embryo is the determinant factor for survival after freezing and that the plastic straw is the most suitable vessel for freezing, storage and transfer of embryos. [less ▲]

Isolement d'une hormone placentaire bovine présentant une activité analogue à la prolactine et à l'hormone de croissance

in Annales de Médecine Vétérinaire (1980), 124

Isolation from bovine cotyledon extracts of an hormone with somatotrophic and mammotrophic activity was performed using this hormone during the successive steps of purification, its prolactinic and ... [more ▼]

Isolation from bovine cotyledon extracts of an hormone with somatotrophic and mammotrophic activity was performed using this hormone during the successive steps of purification, its prolactinic and somatotrophic activity was determined by radioreceptor assay. The purified hormone shows a prolactinic activity similar to that of PRL-NIH-B4 standard and a somatotrophic activity three times that of GH-NIH-B18 standard. [less ▲]

Deep freezing of cattle embryos in glass ampules or French straws

in Theriogenology (1979), 12(2), 79-84

Ninety four cow embryos recovered on day 7-8 after onset of oestrus were frozen by the "Two Step" freezing procedure: 49 in pyrex glass ampules and 45 in .25 ml French semen straws. The overall survival ... [more ▼]

Ninety four cow embryos recovered on day 7-8 after onset of oestrus were frozen by the "Two Step" freezing procedure: 49 in pyrex glass ampules and 45 in .25 ml French semen straws. The overall survival rate was 33.7% (36.2% for embryos frozen in glass ampules; 31.1% for embryos frozen in plastic straws). 45.2% of transferred embryos resulted in pregnancies (35.7% after freezing in glass ampules v.s 52.9% after freezing in plastic straws). [less ▲]