Effect of exogenous LH on plasma concentrations of progesterone and oestradiol in relation to the cessation of egg laying induced by different moulting methods
| Autor: | Hervé Michels, J Vervloesem, Er Kuhn, Eddy Decuypere, Rb Chiasson, G Verheyen |
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| Rok vydání: | 1987 |
| Předmět: |
Muda
Embryology medicine.medical_specialty medicine.drug_class media_common.quotation_subject Oviposition chemistry.chemical_element Biology Calcium Egg laying Endocrinology Internal medicine medicine Animals Progesterone media_common Estradiol Obstetrics and Gynecology Horse Cell Biology Fasting Luteinizing Hormone Diet Zinc Reproductive Medicine chemistry Female Reproduction Gonadotropin Luteinizing hormone Moulting Chickens |
| Zdroj: | Journal of reproduction and fertility. 81(1) |
| ISSN: | 0022-4251 |
| Popis: | Artificially induced cessation of egg laying caused regression of the reproductive tract in hens, as well as changes in circulating concentrations of sex steroids. Hens were bled at several stages during and after artificial moult induced by fasting or overfeeding a diet low in calcium or high in zinc. Hens received a single injection of 200 i.u. of horse LH at Day 0, 7, 21, 35 and 77 (Exp. 1) or Day 0, 8, 23, 35 and 71 (Exp. 2) after start of the treatment to induce moult. Blood samples were taken before and 20, 40 and 60 min (Exp. 1) or 15, 30 and 45 min (Exp. 2) after LH injection. Hens which were fasted or given the diet high in zinc had low plasma progesterone concentrations and the response to LH was reduced or delayed. In hens fed low calcium the reduction in plasma progesterone was less pronounced and the responsiveness to LH was more or less maintained. Conversely, there was no response of oestradiol to LH in laying hens. However, oestradiol concentrations increased in moulting hens after LH injection, due to the high oestradiol secretion from the small white follicles, since all yolky follicles were atretic. |
| Databáze: | OpenAIRE |
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