Use of enzymeimmunoassay (EIA) to measure progesterone and oestrone sulphate in milk and/or plasma for monitoring of fertility in goats

Fertility was monitored in goats during several stages of the reproductive cycle by measurement of progesterone in milk or plasma using radioimmunoassay (RIA). Mean values in milk (strippings) of pregnant and non-pregnant goats at 21 days after mating (p.c.) were approximately 127 and 6 nmol/L, respectively. With a discriminatory level of 32 nmol/L the accuracy of positive pregnancy diagnosis was around 80% and of negative diagnosis was 100%. It was found that the first oestrous cycle after the anoestrous season was preceded by a short period of progesterone elevation with a duration of 3-4 days and with maximum values between 25 and 45 nmol/L. Oestrus induction was studied in limited number of animals. During the anoestrous period ovulatory oestrus was obtained in 60% of the animals (n=10), whereas induction during the breeding season was 100% successful (n=9). Overall lambing rate after induced oestrus was 53%. Discrimination between pregnancy and pseudopregnancy could be done by measurements of oestrone sulphate from day 45 p.c. onwards. The enzymeimmunoassays (EIA) of progesterone in plasma and milk and of oestrone sulphate in plasma were validated. It is concluded that combined measurement of progesterone and oestrone sulphate is a useful method for monitoring of fertility in the goat. Furthermore the technique of EIA can add substantially to the general applicability of these hormone tests. (author). 29 refs, 10 figs, 1 tab