[Experimental studies on the stimulation of prenatal development in swine by PMSG treatment in early pregnancy. 2. Analytic studies of hormones in young sows after PMSG treatment on the 11th day of pregnancy].

Tens gilts received 400 I.U. of Pregmagon on the 11th day of pregnancy (day of KB2 = 1 day of pregnancy), while 8 sows were used as controls. Blood was sampled 4 times a day between the 11th and 25th day of pregnancy, with an indwelling catheter being used. Progesterone, oestradiol-17 beta, and luteinising hormone were radio-immunologically determined. The hormone profiles of pregnant sows were found to differ unambiguously from those of non-pregnant animals for both concentrations and frequencies. They were indicative of close correlations and time links of gonadotrophic and steroid hormones in early pregnancy and in oestrus. PMSG treatment in pregnancy resulted in increase in the oestradiol-17 beta concentration and attenuation in pulsatile luteinising hormone release at the time of implantation. Progesterone concentrations in peripheral blood were not affected by PMSG injection.