Adrenocortical function in cows with the downer cow syndrome. A preliminary report.

To find out if cows with the downer cow syndrome have enhanced or exhausted adrenocortical function, fifteen downer cows were examined for adrenocortical response to 25 IU of adrenocorticotropic hormone (ACTH) between 1 and 9 days postpartum. Of the 15 cows, only two cows recovered following treatment, 10 cows were slaughtered due to poor prognosis and 3 cows were found dead. Four cows with milk fever also were investigated for adrenocortical function. Both the downer cows and cows with milk fever had significantly higher basal and ACTH-stimulated plasma glucocorticoid concentrations than cows without any postpartum complications on day 1 to 2 postpartum (P less than 0.05). There was a tendency that the downer cows which recovered later did not show enhanced adrenocortical function on day 4 to 5 and day 7 to 9 postpartum, while the downer cows with poor prognosis had significantly enhanced adrenocortical activity on the same days postpartum. The enhanced adrenocortical function shown in the milk fever cows on day 1 to 2 postpartum returned to a nearly normal state after their recovery. The results indicate the downer cows with poor prognosis had greatly enhanced adrenocortical function.