[Diagnosis of fertility disorders of the sow by the determination of estradiol and progesterone in the blood serum].

Serum samples of 181 selected sows had been taken the day before culling, reproductive tracts were examined and the culling reasons were recorded. In sows with histories of multiple returns cyclic ovaries were found predominantly. All of the few sows culled for prolonged behavioural oestruses suffered from ovarian cysts. 87% of the sows whose serum oestradiol level exceeded 10 pmol/l and whose serum progesterone level exceeded 2.5 pmol/l revealed ovarian cysts. In 72% of the sows whose hormone concentrations were below these levels inactive ovaries were found. Corpora lutea, partly in association with ovarian cysts were present in 91.1% of the sows whose sera exhibited progesterone levels greater than 2.5 nmol/l and concentrations of oestradiol less than 10 pmol/l. As a rule ovarian diagnoses by combined determination of oestradiol and progesterone could be confirmed by the results of morphological examination of the reproductive tracts. In practice after selection of sows suffering from fertility disorders an even better reliability in diagnosis of ovarian disorders may be achieved than in this investigation.