Effect of Insemination Time and Method on Fertilization and Delivery Rate at the Onset of Estrus Cats

This study was carried out to evaluate the effect of artificial insemination (AI) time and methods on fertilization and delivery rate at onset of estrus cats. Artificial insemination method was used by a transcervical insemination (TCI) or intra-vaginal insemination (IVI) using frozen epididymal sperm (FES) with Norwegian catheter. Semen was collected from epididymal spermatozoa after testis ectomization and frozen in Tris-buffered solution supplemented with 7% glycerol and 0.5% Orvus ES Paste. The concentration of frozen spermatozoa was adjusted to 50×10 sperm/0.25 ml. The CASA data on motility and progressive motility of FES after thawing was approximately 40.3±5.8 and 35.9±6.5%. The female cats were subcutaneously treated with 50 IU pregnant mare serum gonadotropin (PMSG) and ovulated with 100 IU human chorionic gonadotropin (hCG) 4 days after PMSG injection. One treatment was inseminated at 36 h after hCG injection and the other treatment was inseminated immediately hCG injection. At 36 h after hCG injection group, 5 female cats were inseminated TCI or IVI method using 50×10 sperm/0.25 ml per AI. Three of 5 female cats could be inseminated by TCI method and then delivered the 10 kittens from 2 of 3 inseminated females. Immediately hCG injection group, 4 female cats were inseminated TCI or IVI method using same sperm concentration per AI. Two of 4 female cats could be inseminated by TCI method and then delivered the 4 kittens from 1 of 2 inseminated female cats. The results revealed that AI time and method could be affected the fertilization and delivery rates at onset of estrus cats. (