Plasma Corticosterone Response of Turkeys to Adrenocorticotropic Hormone: Age, Dose, and Route of Administration Effects ,

Abstract

Three trials were conducted to investigate plasma corticosterone (B) levels in Large White turkey hens in response to adrenocorticotropic hormone (ACTH) injections at different ages, doses, and routes of administration. In Trial 1, hens were subjected to one of the following treatments at 10, 15, and 20 wk of age: cold water immersion (5 C for 1 min), ACTH injection (10 IU/kg), or saline injection. The plasma B responses to ACTH and cold water immersion followed the same general pattern in all three age groups. Plasma B levels of hens in the ACTH treatment were depressed below control B levels until 6 h postinjection, when they became elevated. Plasma B levels of hens in the cold water treatment were either similar to or increased above those of controls by 2 h posttreatment and were depressed below control levels at .5 h posttreatment at 10 and 15 wk of age. In Trial 2, three dose levels of ACTH (1, 5, and 10 IU/kg) were injected either intramuscularly (IM) or intravenously (IV) in 10-wk-old hens. There was both a dose and route of administration effect. Of the IM-injected hens, only those in the 1-IU ACTH treatment group had significantly (P less than .05) increased plasma B levels and this occurred 4 h postinjection. However, plasma B levels of the 1 and 5-IU IV-ACTH treatment hens were significantly (P less than .05) elevated at .5 h postinjection. Plasma B of the 10-IU IM and IV-ACTH treatments were consistently, but not significantly, lower than controls through 4 h postinjection.(ABSTRACT TRUNCATED AT 250 WORDS)

Research Note: The Absence of Sex and Age Effects on the Corticosterone Response of Turkey Poults to Adrenocorticotropic Hormone and Temperature Stressors

“…The 4-h posttreatment CS response was greater than the CS response occurring 1 h posttreatment, and was very similar to that reported to occur in 10-wk-old turkeys (Davis and Siopes, 1987). All treatment effects were similar at 1 h posttreatment, but at 4 h posttreatment the ACTH treatment increased plasma CS 282% above that of controls.…”

“…Even though a cold stressor (5 C) can induce a robust positive plasma CS response in 10, 15, and 20-wk-old hen turkeys (Davis and Siopes, 1987) this did not occur at either the 5 or 20 C temperature exposures during die first 2 wk of life for hen and torn poults in the present study. Davis and Siopes (1985b) have previously reported that the most consistent response of plasma CS to cold water (5 C) treatment was either no change or depression when measured up to 4 h posttreatment in torn poults to 21 days of age.…”

“…The HPA insensitivity of the poult to acute temperature stress appears to be transitory, as 10-wk-old turkeys have a significant CS response to a cold treatment (Davis and Siopes, 1987). However, the insensitivity of the HPA axis certainly persists through the period of EPM that occurs during the first 2 wk of age and could be involved in this response.…”

Research Note: The Absence of Sex and Age Effects on the Corticosterone Response of Turkey Poults to Adrenocorticotropic Hormone and Temperature Stressors

“…The 4-h posttreatment CS response was greater than the CS response occurring 1 h posttreatment, and was very similar to that reported to occur in 10-wk-old turkeys (Davis and Siopes, 1987). All treatment effects were similar at 1 h posttreatment, but at 4 h posttreatment the ACTH treatment increased plasma CS 282% above that of controls.…”

“…Even though a cold stressor (5 C) can induce a robust positive plasma CS response in 10, 15, and 20-wk-old hen turkeys (Davis and Siopes, 1987) this did not occur at either the 5 or 20 C temperature exposures during die first 2 wk of life for hen and torn poults in the present study. Davis and Siopes (1985b) have previously reported that the most consistent response of plasma CS to cold water (5 C) treatment was either no change or depression when measured up to 4 h posttreatment in torn poults to 21 days of age.…”

“…The HPA insensitivity of the poult to acute temperature stress appears to be transitory, as 10-wk-old turkeys have a significant CS response to a cold treatment (Davis and Siopes, 1987). However, the insensitivity of the HPA axis certainly persists through the period of EPM that occurs during the first 2 wk of age and could be involved in this response.…”

Research Note: The Absence of Sex and Age Effects on the Corticosterone Response of Turkey Poults to Adrenocorticotropic Hormone and Temperature Stressors

“…The 4-h posttreatment CS response was greater than the CS response occurring 1 h posttreatment, and was very similar to that reported to occur in 10-wk-old turkeys (Davis and Siopes, 1987). All treatment effects were similar at 1 h posttreatment, but at 4 h posttreatment the ACTH treatment increased plasma CS 282% above that of controls.…”

“…Even though a cold stressor (5 C) can induce a robust positive plasma CS response in 10, 15, and 20-wk-old hen turkeys (Davis and Siopes, 1987) this did not occur at either the 5 or 20 C temperature exposures during die first 2 wk of life for hen and torn poults in the present study. Davis and Siopes (1985b) have previously reported that the most consistent response of plasma CS to cold water (5 C) treatment was either no change or depression when measured up to 4 h posttreatment in torn poults to 21 days of age.…”

“…The HPA insensitivity of the poult to acute temperature stress appears to be transitory, as 10-wk-old turkeys have a significant CS response to a cold treatment (Davis and Siopes, 1987). However, the insensitivity of the HPA axis certainly persists through the period of EPM that occurs during the first 2 wk of age and could be involved in this response.…”

Research Note: The Absence of Sex and Age Effects on the Corticosterone Response of Turkey Poults to Adrenocorticotropic Hormone and Temperature Stressors

“…The 4-h posttreatment CS response was greater than the CS response occurring 1 h posttreatment, and was very similar to that reported to occur in 10-wk-old turkeys (Davis and Siopes, 1987). All treatment effects were similar at 1 h posttreatment, but at 4 h posttreatment the ACTH treatment increased plasma CS 282% above that of controls.…”

“…Even though a cold stressor (5 C) can induce a robust positive plasma CS response in 10, 15, and 20-wk-old hen turkeys (Davis and Siopes, 1987) this did not occur at either the 5 or 20 C temperature exposures during die first 2 wk of life for hen and torn poults in the present study. Davis and Siopes (1985b) have previously reported that the most consistent response of plasma CS to cold water (5 C) treatment was either no change or depression when measured up to 4 h posttreatment in torn poults to 21 days of age.…”

“…The HPA insensitivity of the poult to acute temperature stress appears to be transitory, as 10-wk-old turkeys have a significant CS response to a cold treatment (Davis and Siopes, 1987). However, the insensitivity of the HPA axis certainly persists through the period of EPM that occurs during the first 2 wk of age and could be involved in this response.…”