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Preovulatory Follicle Development in Goats Following Oestrous Synchronization with Progestagens or Prostaglandins
Author(s) -
FernandezMoro D,
VeigaLopez A,
Ariznavarreta C,
Tresguerres JAF,
Encinas T,
GonzalezBulnes A
Publication year - 2008
Publication title -
reproduction in domestic animals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.546
H-Index - 66
eISSN - 1439-0531
pISSN - 0936-6768
DOI - 10.1111/j.1439-0531.2006.00844.x
Subject(s) - estrous cycle , endocrinology , medicine , follicular phase , follicle , prostaglandin , cloprostenol , biology , ovarian follicle , ovulation , corpus luteum , ovary , hormone
Contents The study reports on differences in the dynamics of growth and functionality of preovulatory follicles in response to oestrous synchronization, either by the administration of two doses of prostaglandin or by an intravaginal progestagen sponge, in goats. The progestagen‐treated group (n = 8) showed more follicles of preovulatory size (≥5.5 mm) than the cloprostenol group (n = 8) during the follicular phase (4.5 ± 0.6 vs 1.9 ± 0.2, p < 0.01). The diameters of the largest follicles (LF1, LF2 and LF3) were also larger in the progestagen group (LF1, 7.8 ± 0.3 vs 7.0 ± 0.2 mm, p < 0.05; LF2, 6.7 ± 0.2 vs 5.6 ± 0.2 mm, p < 0.01; LF3, 5.5 ± 0.3 vs 4.2 ± 0.2 mm, p < 0.01). The study of the preovulatory follicles showed that 27.2% (3/11) of the follicles were in the static phase in the cloprostenol group, whilst 71.4% (10/14) were static in progestagen group (p < 0.05). Higher plasma oestradiol levels were recorded in the progestagen‐treated goats during the 48 h prior to cloprostenol injection or progestagen withdrawal (4.2 ± 0.4 vs 3.0 ± 0.2 pg/ml, p < 0.05). In conclusion, goats with oestrus synchronized by progestagen showed a higher number of preovulatory‐sized follicles, but a decreased oestradiol secretion when compared with does with oestrus synchronized by using prostaglandin analogues. These would support the development of alternative protocols for assisted reproduction.