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University of Missouri, Columbia 65211
ABSTRACT
A study was conducted to determine if charcoal-extracted follicular fluid inhibits FSH-induced follicular development in prepuberal heifers. Thirty-six prepuberal heifers were allotted by breed and weight to a 2 x 2 factorial experiment involving charcoal-extracted follicular fluid and FSH treatments. Heifers were unilaterally ovariectomized and injected (intravenously; 10 ml) every 8 h for 88 h with either charcoal-extracted follicular fluid or saline. Follicle-stimulating hormone (2 mg) or saline was injected (intramuscularly) every 8-h starting 24 h after initiation of charcoal-extracted follicular fluid to 88 h following unilateral ovariectomy. Plasma samples were collected at 8-h intervals from 48 h prior to unilateral ovariectomy to 96 h following unilateral ovariectomy when the remaining ovary was removed. Follicular fluid and total ovarian weight increased following FSH treatment. The increases were not inhibited by charcoal-extracted follicular fluid. Total number of surface follicles was similar among treatments. However, FSH induced a shift in follicular diameter from small (
3 mm) to medium (7 to 9 mm) or large (10 to 13 mm) follicles, which was unaffected by charcoal-extracted follicular fluid. Plasma concentration of FSH, but not LH, declined following charcoal-extracted follicular fluid administration. In summary, charcoal-extracted follicular fluid did not inhibit FSH-induced follicular development in prepuberal heifers when charcoal-extracted follicular fluid was administered at a dosage that reduced circulanng concentration of FSH by approximately 40%.
1 Contribution from the Missouri Agricultural Experiment Station Journal Series Number 10552 and NC-113 Regional Research Project, Methods for Improvement of Fertility in Cows Postpartum.
2 Dairy Science Department; reprint requests.
4 Department of Veterinary Medicine and Surgery.
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