Ovulatory follicle dysfunction in lactating dairy cows after treatment with Folltropin-V at the onset of luteolysis
| Autor: | G. M. Schuenemann, D. A. Roper, N. R. Rohrbach, Jennifer L. Edwards, F. N. Schrick, Tulio M Prado, Arnold M. Saxton, Julio O. Giordano, F. A. Di Croce |
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| Rok vydání: | 2013 |
| Předmět: |
endocrine system
medicine.medical_specialty media_common.quotation_subject medicine.medical_treatment Luteolysis Ovary Chorionic Gonadotropin Drug Administration Schedule Gonadotropin-Releasing Hormone Andrology Ovarian Follicle Ovulation Induction Food Animals Internal medicine medicine Animals Lactation Ovulation Inhibition Small Animals Ovulation Saline media_common Estrous cycle Ovulatory follicle Equine business.industry Fertility Agents Female Luteinizing Hormone Dairying Controlled internal drug release Endocrinology medicine.anatomical_structure Cattle Female Animal Science and Zoology Follicle Stimulating Hormone business hormones hormone substitutes and hormone antagonists After treatment |
| Zdroj: | Theriogenology. 79:1210-1217 |
| ISSN: | 0093-691X |
| Popis: | The objective was to examine growth of the ovulatory follicle after FSH (Folltropin-V; Bioniche Animal Health, Belleville, Ontario, Canada) was given at the onset of induced luteolysis during a synchronization of ovulation protocol. Using GnRH or hCG for inducing ovulation enabled assessing ovulatory follicle responsiveness to an endogenous versus exogenous surge of LH activity. At 8 to 10 days after estrus (synchronized estrus = Day 0), lactating dairy cows received an Eazi-Breed CIDR (Pfizer Animal Health) plus 100 μg GnRH. After 7 days, controlled internal drug release devices (CIDRs) were removed, cows were given 500 μg cloprostenol, and then randomly allocated to receive 80 mg Folltropin-V (FSH; N = 19) or 4 mL sterile saline (SAL; N = 16). After 49 hours, FSH and SAL cows were randomly allocated to receive 100 μg GnRH or 3000 IU hCG. Five cows ovulated 30 to 42 hours (38.4 ± 1.2 hours) after FSH treatment. In the remaining FSH (N = 14) or SAL (N = 16) cows, ovulatory follicle size was similar at CIDR removal (14.5 ± 0.6 and 14.7 ± 0.6 mm, respectively; P = 0.85) and when GnRH/hCG was given (16.6 ± 0.6 and 17.7 ± 0.6 mm, respectively; P = 0.23). Estradiol-17β concentrations were lower in FSH cows at 36 and 49 hours after CIDR removal (FSH by time interaction, P < 0.005). After GnRH or hCG treatment, four FSH cows failed to ovulate. In cows exhibiting ovulation, the last recorded size of the ovulatory follicle was not influenced by FSH (18.1 ± 0.9 and 17.5 ± 0.6 mm for FSH and SAL, respectively; P = 0.59) or hormonal induction approach (18.4 ± 0.9 and 17.2 ± 0.7 mm for GnRH and hCG, respectively; P = 0.29). The interval from onset of luteolysis to ovulation and pharmaceutical induction to ovulation was shorter in FSH cows given GnRH (FSH by pharmaceutical inducer [GnRH vs. hCG] interaction; P = 0.01). Cows receiving GnRH had an LH surge; hCG-treated cows did not. Maximum LH concentrations were greater (P < 0.04) in SAL versus FSH cows after GnRH treatment (10.9 ± 1.2 vs. 6.7 ± 1.4 ng/mL, respectively). In three FSH cows failing to ovulate after GnRH treatment, the maximum LH concentration was |
| Databáze: | OpenAIRE |
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