Efficacy of short-term administration of altrenogest to postpone ovulation in mares |
| |
| Institution: | 1. Departamento de Medicina y Cirugía Animal, Facultad de Veterinaria, Universidad CEU Cardenal Herrera, Valencia, Spain;2. Equine Reproductive Services (UK) Limited, Old Malton, North Yorkshire, UK;3. Equine Fertility Clinic, Brownhills, West Midlands, UK;4. Departamento de Producción Animal, Facultad de Veterinaria, Universidad CEU Cardenal Herrera, Valencia, Spain;5. Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands;1. Departamento de Medicina y Cirugía Animal, Facultad de Veterinaria, Universidad CEU Cardenal Herrera, Valencia, Spain;2. Producción Equina, Facultad de Agronomía y Veterinaria, Universidad Nacional de Río Cuarto, Córdoba, Argentina;3. Ansager Dyrehospital, Ansager, Denmark;4. Warren House Farm, Equine Fertility Clinic, Brownhills, West Midlands, UK;1. Department of Animal Reproduction and Veterinary Radiology, School of Veterinary Medicine and Animal Science, UNESP, Botucatu, São Paulo, Brazil;2. Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Champaign-Urbana, Illinois, United States;3. School of Animal Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, United States;1. Faculty of Veterinary Medicine, Department of Equine Sciences, Utrecht University, Utrecht, The Netherlands;2. Department of Production Animal Medicine, Equine Reproduction, Helsinki University, Finland;3. Cantero de Letur S.L., Letur, Spain;1. Department of Animal Science, Food and Nutrition, Southern Illinois University, Carbondale, IL, USA;2. Laboratory of Manipulation of Oocytes and Preantral Follicles (LAMOFOPA), Faculty of Veterinary Medicine, State University of Ceará, Fortaleza, Ceará, Brazil;3. Department of Veterinary Medicine, Sousa Campus, Federal Institute of Education, Science and Technology of Paraíba, Sousa, Paraíba, Brazil;4. National Institute of Agricultural Research, INIA La Estanzuela, Colonia, Uruguay;5. Postgraduate Program of Gynecology and Obstetrics, Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil;6. Animal Bioscience Postgraduate Program, Federal University of Goiás, Jataí, Goiás, Brazil |
| |
| Abstract: | Estrogen from a growing follicle stimulates the preovulatory surge of luteinizing hormone (LH) while progesterone (P) is known to suppress LH. The possibility exists that administration of P, in the presence of an ovulatory follicle, would sufficiently suppress LH and, therefore, delay ovulation. The objective of this research was to elucidate the potential for oral administration of altrenogest (17-Allyl-17β-hydroxyestra-4,9,11-trien-3-one) to postpone ovulation of a preovulatory follicle (35 mm) for approximately two days. Fourteen light-horse mares, ranging in age from two to 19 years, were randomly assigned to one of three treatments (A-.044 mg/kg BW altrenogest for two days; B-.088 mg/kg BW altrenogest for two days; and C- no altrenogest). Mares began treatment when a 35-mm or greater follicle was observed via real-time transrectal ultrasonography. Both number of days until ovulation and follicular maintenance differed between treated and control mares. Number of days until ovulation was increased (P<.05) for mares in treatment A when compared with the control mares. Follicular diameter maintenance, a measurement of follicular diameter throughout treatment, also increased (P<.05) for mares in treatment A when compared with the control mares. Mean LH concentration was not different between mares treated with altrenogest at either treatment dose when compared with the control mares. Pregnancy rates and embryonic vesicle size change were also measured to determine potential effects of altrenogest administration. No differences (P>.05) were found in either characteristic.Short-term administration of altrenogest increased the number of days to ovulation. Further study is warranted to prove conclusively that altrenogest increases follicular maintenance, alters the preovulatory LH surge, and has no detrimental effects upon reproductive efficiency. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
