Wellenberg G J, Borst G H, Bouwkamp F T
Gezondheidsdienst voor Dieren in Overijssel en Flevoland, Zwolle.
Tijdschr Diergeneeskd. 1989 Jan 1;114(1):14-6.
The concentration of oestrone sulphate was determined in plasma as well as in urine to verify early pregnancy in pigs (within 24-29 days after mating). The threshold level in plasma was 0.70 ngr/ml. and in urine 50 ngr/ml. Accuracy was ninety-nine per cent in samples of plasma and ninety-two per cent in samples of urine respectively.