The hypothalamo-pituitary-adrenal (HPA) axis in sheep is attenuated during lactation in response to psychosocial and predator stress
| Autor: | C. R. Ralph, Alan J Tilbrook |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Restraint Physical medicine.medical_specialty endocrine system Hyporesponsiveness Hypothalamo-Hypophyseal System Hydrocortisone Offspring Pituitary-Adrenal System Stress Oxytocin Article 03 medical and health sciences 0302 clinical medicine Endocrinology Dogs Food Animals Stress Physiological Internal medicine Lactation medicine Animals Predator Sheep business.industry HPA axis Animals Suckling 030104 developmental biology Plasma cortisol medicine.anatomical_structure Predatory Behavior Psychosocial stress Animal Science and Zoology Female Vocalization Animal business Psychosocial 030217 neurology & neurosurgery hormones hormone substitutes and hormone antagonists Stress Psychological medicine.drug |
| Zdroj: | Domestic Animal Endocrinology |
| ISSN: | 1879-0054 0739-7240 |
| Popis: | Activation of the hypothalamo-pituitary-adrenal (HPA) axis by psychosocial stress is attenuated during lactation. We tested the hypothesis that lactating ewes will have attenuated HPA axis responses to isolation and restraint but will have greater responses to predator stress in the form of barking dogs. We imposed two 4 h stressors: psychosocial stress (isolation and restraint of ewes) and predator stress (barking dogs). Blood was collected intravenous every 10 min from nonlactating ewes (n = 6), lactating ewes with lambs present but not able to be suckled (n = 6), and lactating ewes with lambs present and able to be suckled (n = 6). Plasma cortisol and oxytocin were measured. For nonlactating ewes, cortisol increased (P < 0.01) in response to both stressors, and these increases were greater (P < 0.01) than that in the lactating animals. For lactating ewes with lambs present but unable to be suckled, cortisol increased (P < 0.05) in response to both stressors with a greater response to barking dogs (P < 0.05). For lactating ewes with lambs present and able to be suckled, cortisol increased (P < 0.01) in response to barking dogs only. Plasma oxytocin was greater (P < 0.01) in lactating ewes than in nonlactating ewes and did not change in response to the stressors. In conclusion, lactating ewes are likely to have a greater HPA axis response to a stressor that may be perceived to threaten the welfare of themselves and/or their offspring. The role of oxytocin in attenuation of the HPA axis to stress in sheep is unclear from the current research and requires further investigation. Highlights • The response of the hypothalamo-pituitary-adrenal axis to stress is attenuated during lactation in sheep. • The extent of this attenuation is influenced by the opportunity to suckle lambs and the type of stressor. • Stressors that pose an immediate threat to the offspring evoke greater stress responses. |
| Databáze: | OpenAIRE |
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