Hormone profile of crossbred goats during the periparturient period.

The plasma hormone profile of progesterone, 17 beta-oestradiol, prolactin, growth hormone (GH), cortisol, triiodothyronine (T3), thyroxine (T4) and insulin were estimated by radioimmunoassay in jugular blood samples from 10 Alpine x Beetal crossbred goats during the periparturient period. The plasma progesterone concentrations declined from day 20 prior to kidding to the day of kidding and then remained at a basal level. 17 beta-Oestradiol concentrations declined from day 20 to day 4 prepartum, followed by a continuous increase to reach a peak at kidding. Plasma oestradiol declined abruptly on day 1 postpartum and remained low throughout the postpartum period. The plasma prolactin concentrations increased continuously from day 20 to day 10 prepartum but then increased to a peak on the day of kidding, followed by a transient decline by day 5 postpartum. The plasma GH concentrations varied significantly (p < 0.01) on the different days of sampling but were highest on the day of kidding. The plasma cortisol concentration declined from day 20 to day 2 prepartum, after which it abruptly increased on day 1 prepartum to reach a peak on the day of kidding. The concentrations of plasma T3 remained similar during the prepartum period but were minimal on the day of kidding and increased during the postpartum period. The concentration of plasma T4 was also lowest on the day of kidding and increased during the postpartum period. Plasma insulin concentrations were low in the day of kidding.