Krause ART, Dias FCF, Adams GP, Mapletoft RJ, Singh J. Antral follicle counts and association with ovarian superstimulatory response to gonadotropins in prepubertal calves.
Anim Reprod Sci 2021;
227:106730. [PMID:
33652359 DOI:
10.1016/j.anireprosci.2021.106730]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 02/15/2021] [Accepted: 02/16/2021] [Indexed: 11/30/2022]
Abstract
Antral follicle count (AFC) repeatability at the time of follicular wave emergence and duration of gonadotropin treatment in calves with small and large AFC affects the superstimulatory response of follicles. In Study I, the individual AFC was determined, calves were ranked as having a small, medium or large AFC, and a second count was performed prior to FSH treatments. There was a positive association between the number of follicles ≥1 mm after the first and second counts (r = 0.4; P = 0.003). In Study II, calves with small and large AFC were administered pFSH for 4 or 7 days, pLH 20 h after last pFSH administration and cumulus-oocyte-complexes (COC) were collected. In calves having large as compared with small AFC, number of follicles ≥6 mm were greater (P = 0.01) and COC collected were greater (P = 0.001). The proportion of large-sized follicles (>9 mm) was greater in the 7-day than in the 4-day gonadotropin treatment group (56.4 ± 8.3 and27.8 ± 7.5 %, respectively; P = 0.01). In Study III, there was a positive association between AFC and number of follicles ≥6 mm at the time of COC collection (r = 0.6; P = 0.003). In summary, the number of follicles at the time of follicular wave emergence was associated with the number of follicles recruited during subsequent waves of follicular development and ovarian response following gonadotropin superstimulation. Calves with a large AFC had more COC collected than calves with a small AFC.
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