Hormonal studies in postpartum female camels and their neonates

Abstract

The expulsion of the fetus from the mother at parturition necessitates reorganization of the endocrine status in both individuals. In this study, the patterns of hormonal changes were investigated in postpartum Dromedary camels and their neonates. Blood samples were recovered within a few hours after calving from 10 female Dromedary camels and their calves, and sampling was continued at varying intervals upto Day 21 post partum. Sera were assayed for progesterone, cortisol and thyroid hormone concentrations by specific radioimmunoassays. Progesterone concentrations in the dams varied between 0.5 and 2.0 ng/ml on the day of calving and declined steadily thereafter to become undetectable by Day 9; progesterone remained undetectable in the neonates. Cortisol concentrations were high (25 to 30 ng/ml) at parturition in both the dams and their calves. They declined to 6 to 7 ng/ml in the dams, but became undetectable in the neonates by Day 14 post partum. The thyroid hormones were low in the dams (T 4 = 70; T 3 = 1.6 ng/ml) on Day 1 post partum but then increased gradually to Day 21 (T 4 = 110; T 3 = 2.2 ng/ml). In contrast, thyroid hormone concentrations in the neonates were 4 to 5 times higher than those of their mothers at birth. They declined thereafter but nevertheless remained at almost double the concentrations found in the dams.