• Korean Journal of Agricultural Science
• /
• v.35 no.2
• /
• pp.167-176
• /
• 2008

Supplementation of serum and estrogen in in vitro maturation(IVM) medium was shown to improve embryo development and quality in several species. This study investigates the effect of ovarian estrus stage on canine oocyte quality and supplementation of medium with canine serum or estrogen on IVM of canine oocytes. As results, in experimental 1, IVM oocytes collected from follicular stage ovaries to MII stages($10.2{\pm}1.5%$) was higher (p<0.05) with 10% canine estrus stage serum than control($1.3{\pm}1.6%$), anoestrus stage serum($4.0{\pm}1.6%$), luteal stage serum($2.7{\pm}1.7%$) and 10% FBS($1.3{\pm}1.6$). In experimental 2, 10% canine estrus stage serum supplementation has highest maturation rate to MII stages($10.0{\pm}1.8%$) and there were significant differences(P<0.05) with another treatment in follicular stages group. In order to investigate the synergic effect of estrous serum and estrogen supplementation, different estrous stage groups of oocytes were cultured with 2 ug/ml estrogen plus various concentrations of different reproductive stage serum and FBS(experimental 3). As results, the rate of maturation to metaphase II(MII) stage was significantly higher(p<0.05) in oocytes from the follicular stage supplemented with estrogen and 10% canine estrus stage serum(11.5%) compared to the other groups(6.0 - 8.8%). The present study was demonstrated that canine serum and the estrus cycle of the bitch affect the meiotic competence of oocytes. Hormonal influences within the follicle may be one of the factors responsible for the greater proportion of maturation of oocyte to MII from bitches at the follicular phase.

• Journal of Embryo Transfer
• /
• v.23 no.1
• /
• pp.13-18
• /
• 2008

Vaginal cytology with behavioral observation was performed in 34 estrous cycles in 16 Miniature Schnauzer dogs to evaluate the its usefulness. The mean duration of proestrus and estrus in Miniature Schnauzer based on behavioral observation and vaginal cytology was $7.58{\pm}1.50$ (Mean ${\pm}$S.D., range: $5{\sim}10$) and $8.46{\pm}2.82\;(6{\sim}17)$ days for proestrus, and $6.97{\pm}1.66\;(4{\sim}10)$ and $10.29{\pm}2.61\;(6{\sim}19)$ days for estrus, respectively. The duration of each phase of the estrous cycle was not significantly different based on between behavioral observation and vaginal cytology. The gestational length from the first day of male acceptance was $66.55{\pm}2.91\;(64{\sim}76)$ days, $57.70{\pm}1.92\;(54{\sim}62)$ days from the first male refusal, and $56.90{\pm}1.62\;(54{\sim}60)$ days from the onset of cytologic diestrus, respectively. Vaginal cytology during the estrous cycle were significantly characteristic of large intermediate cells in proestrus, anuclear cells in estrus, small intermediate cells in diestrus, and parabasal cells and small intermediate cells in anestrus (p<0.001), respectively. Cornification index (CI) by vaginal cytology was higher in proestrus ($69.90{\pm}1.44%$) and estrus ($91.35{\pm}1.09%$), then it was decreased in diestrus ($13.53{\pm}1.28%$) and anestrus ($1.16{\pm}1.26%$).