HomePhilippine Journal of Veterinary Medicinevol. 44 no. 1 (2007)

Successful Pregnancies in Philippine Native Bitches Artificially Inseminated Once or Twice Using Frozen-Thawed Rotweiller Somen

Joseph Emil C. Rubico | Alma Michelle T. Madamba | Benjamin Reuel G. Marte | Conrado A. Valdez

Discipline: Veterinary Medicine



This study was undertaken to determine the conception rates after artificially inseminating Philippine native bitches with frozen-thawed canine semen on the first day of estrus (single insemination) or first and fifth days of estrus (double insemination). Semen was collected by digital manipulation from an apparently healthy Rotweiller stud. The collected semen was subjected to gross and microscopic examination to determine its viability for freezing and insemination. Only semen with motility rate of 60% or higher was frozen using a Tris-raffinose-eggyolk extender containing glycerol as cryoprotectant. The frozen semen was stored in liquid nitrogen until use. Frozen-thawed semen with a motility rate of 30% or higher was then artificially inseminated into the vagina of adult Philippine native bitches. Sixteen apparently healthy native Philippine bitches were assigned into two treatment groups. Half of the bitches were inseminated only once at the first day of estrus or twice on the first and fifth days of estrus. Heat detection was based on clinical signs and examination of vaginal smears. This study yielded 25% conception rate for single insemination and 50% conception rate for double insemination of frozen-thawed canine semen. All the pregnant bitches were allowed to whelp producing healthy puppies. Based on available literature reviewed, this is the first report on the successful artificial insemination of Philippine native bitches using frozen-thawed canine semen. However, based on the results of this study, further research on optimizing the canine freezing protocol, number and timing of insemination and other factors affecting semen quality are warranted.