Short term administration of cyproterone acetate for contraception: Effects on testosterone secretion and semen characteristics in rams (Ovis aries) and bucks (Capra hircus)

Aim of study: To examine the influence of administering cyproterone acetate (CPA), at the beginning of the mating season, on the testosterone concentration and morphometric and functional characteristics of ram and buck semen.Area of study: Madrid, SpainMaterial and methods: Five rams and five bucks were intramuscularly administered 200 mg of CPA in 2 mL of olive oil twice per week - from July 1st to 31st in the rams, and from August 1st to 31st in the bucks. Five control animals of each species were administered 2 mL of olive oil. Blood samples and ejaculates analysed from the start of treatment until eight weeks after the last day of treatment.Main results: GLM-ANOVA showed the interaction species × CPA treatment to have effect (p