Relationship of Vulvar Swelling to Estrus in Mink

The Annual Reproductive Cycle of Mink (Mustela Vison)

“…Fur development of an additional 30 females, ovariohysterectomized between July and September, was also scored. From October to March, at 1-to 4-week intervals, the testis volume of each male was measured by the method of and vulval swelling of 20 to 76 females was scored on a scale of 0 to 3 (Travis et aL, 1978). Data obtained after March 9 were from mink that mated one or more times during a 2to 8-day period between March 1 and March 17.…”

“…Throughout 6 to 8 weeks of lactation and subsequent 5 to 6 months of apparent ovarian quiescence (anestrus) there are no externally visible morphological or behavioral manifestations of reproductive activity. Following the winter solstice and throughout the month of January females may exhibit some vulval swelling but will not mate (proestrus) and males experience moderate testes growth (Travis et al, 1978;Onstad, 1967). The breeding season is the 3-to 4-week period around the time of the vernal equinox (March 21)throughout which most females appear to be constantly sexually receptive (estrus) and exhibit maximal vulval swelling, tn mink mated early in the season, another wave of mature follicles may be ovulated in response to a second mating 6 to 8 days after the first (Hansson, 1947).…”

Reproduction and fertility in the mink (Mustela vison)

“…A better re¬ sponse to PMSG is seen immediately after the breeding season than during anoestrus (Hartsough, 1942). The developmental stages of the external genitalia have been classified into 3 or 4 categories (Travis et al, 1978). Ovariectomized animals receiving diethylstilboestrol did not develop vulvar size large enough to permit intromission although they exhibited clear willingness to mate (Enders, 1948).…”

“…Ovariectomized animals receiving diethylstilboestrol did not develop vulvar size large enough to permit intromission although they exhibited clear willingness to mate (Enders, 1948). Although vaginal smears can be useful to predict when the female will not mate, they cannot be used to predict the opposite (Travis et al, 1978). Like the ferret, embryo transfer has been applied to mink (Chang, 1968;Adams, 1982;Zhelezova & Sekirina, 1982;Kraemer, 1983).…”

Effects of zearalenone and/or tamoxifen on swine and mink reproduction

“…The diets were fed ad libitum throughout the breeding, whelping and lactation periods (until the kits reached 3 weeks of age). The females were examined for evidence of vulvar swelling (an indication of estrus) on 4 March 1992 (day 48 of treatment) and scored according to the criteria proposed by Travis et al 23 Beginning on 4 March 1992 (day 48 of treatment), the female mink were mated to untreated males. The females were provided an opportunity to mate every fourth day until a positive mating (verified by the presence of motile spermatozoa in vaginal aspirations) was obtained.…”