Endocrine changes in sows exposed to elevated ambient temperature during lactation
| Autor: | C.H. Rahe, C R Barb, D. N. Marple, George B. Rampacek, R R Kraeling, James L. Sartin, M J Estienne |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
Litter (animal)
endocrine system medicine.medical_specialty Hot Temperature Hydrocortisone Swine Thyrotropin-releasing hormone Gonadotropin-releasing hormone Gonadotropin-Releasing Hormone Eating Endocrinology Milk yield Food Animals Internal medicine Lactation Naloxone medicine Animals Endocrine system Thyrotropin-Releasing Hormone Progesterone Chemistry Luteinizing Hormone IV injection Prolactin medicine.anatomical_structure Female Animal Science and Zoology hormones hormone substitutes and hormone antagonists medicine.drug |
| Zdroj: | Domestic Animal Endocrinology. 8:117-127 |
| ISSN: | 0739-7240 |
| DOI: | 10.1016/0739-7240(91)90046-m |
| Popis: | Seven sows were placed into one of two environmental chambers at 22 C, 5 d prior to farrowing. On day 9 of lactation, one chamber was changed to 30 C (n = 4) and the other remained at 22 C (n = 3). On days 24 and 25, blood samples were collected every 15 min for 9 hr and 7 hr, respectively. On day 24, thyrotropin releasing hormone (TRH) and gonadotropin releasing hormone (GnRH) were injected iv at hour 8. On day 25 naloxone (NAL) was administered iv at hour 4 followed 2 hr later by iv injection of TRH and GnRH. Milk yield and litter weights were similar but backfat thickness (BF) was greater in 22 C sows (P less than .05) compared to 30 C sows. Luteinizing hormone (LH) pulse frequency was greater (P less than .003) and LH pulse amplitude was less (P less than .03) in 22 C sows. LH concentrations after GnRH were similar on day 24 but on day 25, LH concentrations after GnRH were greater (P less than .05) for 30 C sows. Prolactin (PRL) concentrations were similar on days 24 and 25 for both groups. However, PRL response to TRH was greater (P less than .05) on both days 24 and 25 in 30 C sows. Growth hormone (GH) concentrations, and the GH response to TRH, were greater (P less than .0001) in 30 C sows. Cortisol concentrations, and the response to NAL, were less (P less than .03) in 30 C sows. NAL failed to alter LH secretion but decreased (P less than .05) PRL secretion in both groups of sows. However, GH response to NAL was greater (P less than .05) in 30 C sows. Therefore, sows exposed to elevated ambient temperature during lactation exhibited altered endocrine function. |
| Databáze: | OpenAIRE |
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