Changes in the blood cortisol levels during the first week of life in calves (Bos taurus) and lambs (Ovis aries)]

At birth, the plasmatic level of cortisol is very variable and very high in the new-born Calf or the newborn Lamb. This level diminishes within one day and then varies between 10 and 30 ng/ml during the six following days. In the Calf, the secretion of cortisol can be directly stimulated by ACTH or inhibited at the level of the hypothalamic and hypophyseal system with dexamethasone on the day following birth.