Reproduction · 1970 · 41 citations · 10 references
Veterinary MedicineAnimal SciencesGynecologyFertilityIn Vitro FertilizationReproductive MedicineOogenesisOvarian CycleOvarian FunctionRuminant ReproductionRuminant Reproductive MedicineCow Reproductive PhysiologyFollicular Development AssessmentFollicular Development RegulationOvulation MechanismsOvulation PhysiologyOvulation Rate
Summary. Holstein calves, reared from birth under standard conditions, were given various combinations of pmsg-lh or pmsg-hcg at 8 to 9 weeks, or at 17 weeks of age. Follicular development was variable, but averaged fifty-three follicles≥1·0 cm in diameter following administration of either 1500 or 2000 i.u. of pmsg. Ovulation rate was 79% following 50 mg of lh, but it was only 16% following 1500 i.u. of hcg. The presence of young corpora lutea or the administration of progesterone accelerated transport of ova into the uterus and was associated with a reduced percentage of cleaved ova and a lower recovery rate. Liquid semen was superior to frozen semen in initiating cleavage of ova. Under optimum conditions, approximately 75% of the developed follicles ovulated and a similar proportion of ova was cleaved at the time of collection or cleaved in culture. Recovery rate was usually less than 30%.
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