Adrenal Glucocorticoid Response to Exogenous Adrenocorticotropin Mediated by Density and Social Disruption in Lactating Cows

摘要: Abstract Two experiments with lactating Holsteins monitored time required for alterations in adrenal glucocorticoid output response to injection of 200 IU adrenocorticotropin after exposure increased density and social disruption. First, cows two replicates nine each were assigned randomly across age either zero (control), 2-day, or 9-day into a high (3.96m 2 lot space .67 free stalls per cow) group. Response curves indicated potential within days. In another experiment, 16 equally 1, 2, 3 days higher (2.97m .5 adjustment new herd. Mean integrated responses 161.6±12.6, 158.2±28.2, 227.7±32.2, 229.9±40.3 ng/ml±standard deviations. Days differed from controls showing that response, as measured by glucocorticoids, occurs No differences bacteriological status, somatic cell counts quarter milk, milk production observed.