L'inactivité ovarienne saisonnière chez la jument 1- Aspects physiologiques

National audienc

Seasonality in mares

International audienc

Incidence of spontaneous ovulation in young, group-housed cats based on serum and faecal concentrations of progesterone

Cats are considered to be reflex ovulators that exhibit a luteal phase (pregnancy or pseudopregnancy) only after copulatory stimulation In a group-housed colony of 15 1-year-old domestic queens, 23 noncopulatory, spontaneous ovulations were observed in 87% of the queens over 4.5 months based upon the detection of increased concentrations of progesterone in faeces, serum, or both. Luteal phases were detectable for periods of 3 to 5 weeks with peak progesterone concentrations averaging 21 +/- 1 ng ml(-1) in serum and 1874 +/- 281 ng g(-1) in faeces. Individual fats exhibited from 0 to 3 spontaneous ovulations and subsequent pseudopregnancies each. A male was added to a separate cage within the room during the last 1.5 months of the study. The incidence of ovulation per 10 day period ranged from 0% to 22% before introduction of the male and from 33% to 57% immediately after introduction of the male, suggesting a potential noncopulatory influence of the male on the incidence of spontaneous ovulation in young,group-housed cats

Changes in PGF 2 alpha secretion during prolonged luteal phase in mares

International audienc