Activation of the hypothalamic-pituitary-adrenal (HPA) axis is the defining feature of the stress response. Under the influence of both internal and external stressors, activation of the HPA axis causes increased synthesis of corticotropin-releasing hormone (CRH) in the hypothalamus. The objective this study was to determine an appropriate exogenous dose of bovine corticotropin-releasing hormone (bCRH) to stimulate the physiological effects of the HPA axis in steers as a method to test the sensitivity of the pituitary and adrenal gland. 14-month old Holstein-Friesian steers were either given saline (control) or bCRH (0.1, 0.3, 1.0 or 1.5 \u00ecg\/kg BW). Serial blood samples were collected at -15, 0, 15, 30, 45, 60, 75, 90, 105, 120, 135, 150, 165, and 180 min relative to time 0. Following administration of 0.1 \u00ecg of bCRH\/kg BW, the peak ACTH response was not significantly different from pretreatment baseline concentrations. Administration of 0.3, 1.0, and 1.5 \u00ecg of bCRH\/kg BW increased peak ACTH above pretreatment concentrations. Peak cortisol responses to all bCRH treatments were greater than those to pretreatment concentrations. In conclusion, bCRH challenge may be a useful method for testing the sensitivity of the hypothalamic-pituitary-adrenal axis in steers subjected to stressful husbandry conditions, and a minimum dose of 0.3 \u00ecg of bCRH\/kg BW is required to stimulate physiological effects of stressor hormones.<\/p>\n","protected":false},"excerpt":{"rendered":"
Activation of the hypothalamic-pituitary-adrenal (HPA) axis is the defining feature of the stress response. Under the influence of both internal and external stressors, activation of the HPA axis causes increased synthesis of corticotropin-releasing hormone (CRH) in the hypothalamus. The objective this study was to determine an appropriate exogenous dose of bovine corticotropin-releasing hormone (bCRH) to […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[928],"tags":[4299,8882,1972,14804,20792,3465,22808,16262,110,20911,1579,52],"class_list":["post-5293","post","type-post","status-publish","format-standard","hentry","category-welfare","tag-adrenocorticotropic-hormonechallengecorticotropin-releasing-hormonecortisolhormoneshypothalamic-pituitary-adrenal-axisresponsesteersstressstress-response","tag-al","tag-condition","tag-hal","tag-influence","tag-pea","tag-pic","tag-pl","tag-stress","tag-t","tag-test","tag-treatment"],"_links":{"self":[{"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/posts\/5293","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/comments?post=5293"}],"version-history":[{"count":0,"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/posts\/5293\/revisions"}],"wp:attachment":[{"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/media?parent=5293"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/categories?post=5293"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/tags?post=5293"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}