Ovarian follicular wave emergence after treatment with progestogen and estradiol in cattle

Bo, G.A., Adams, G.P., Caccia, M., Martínez, M., Pierson, R.A. and Mapletoft, R.J. (1995) Ovarian follicular wave emergence after treatment with progestogen and estradiol in cattle. Animal Reproduction Science, 39 (3). pp. 193-204. ISSN 0378-4320

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Resumen

An experiment was designed to evaluate the effects of treatment with progestogen and estradiol-17β (E-17β), in combination, at different stages of development of the dominant follicle, on follicular development and subsequent wave emergence. Cross-bred beef cows (n = 12) and heifers (n = 25) were randomly allocated to one of four treatment groups on Day 0 (ovulation). Treatment groups were untreated control animals and those that were given progestogen ear implants on Day 2, 5 or 8 and injected intramuscularly with 5 mg E-17β in sesame oil on Day 3, 6 or 9, respectively. Ovarian ultrasonography was performed daily from Day 0 until progestogen implant removal, 4 days after the emergence of the post-treatment follicular wave. The mean (± SEM) time (days) to cessation of growth and onset of regression of the dominant follicle of the first wave were earlier (P < 0.05) in the Day 3 treatment group than in the control group (3.6 ± 0.2 vs. 5.6 ± 0.4 and 7.0 ± 0.3 vs. 11.0 ± 0.6, respectively). Characteristics of the dominant follicle of the first wave in the Day 6 and Day 9 treatment groups were not different from those of the control group. However, treatment on Day 9 resulted in earlier (P < 0.05) cessation of growth and onset of regression of the dominant and largest subordinate follicle of the second wave than in the control group (9.6±0.2 vs. 13.4±0.7 and 11.5±1.3 vs. 17.1±0.9, respectively). Follicle wave dynamics was affected by early emergence of the second follicular wave in heifers treated on Day 3 (Day 7.3 ± 0.3) and delayed emergence in those treated on Day 6 (Day 10.7 ± 0.2) compared with the control group (Day 8.6 ± 0.3; P < 0.05). Furthermore, treatment on Day 9 resulted in earlier (P < 0.05) emergence of the third wave (Day 13.1 ± 0.3) than the control group (Day 15.3 ± 0.6). The interval from treatment to wave emergence was not different among treatment groups (4.3 ± 0.2 days after E-17β) and supported the hypothesis that treatment with progestogen plus E-17β results in consistent emergence of a new follicular wave, regardless of the stage of development of the dominant follicle at the time of treatment. It was concluded that treatment with progestogen and E-17β in combination can be used effectively to control and synchronize follicle wave development.

Tipo de documento:	Artículo
DOI:	https://doi.org/10.1016/0378-4320(95)01389-H
Palabras clave:	Cattle-ovary. Dominant follicle. Estradiol. Follicular wave emergence. Progestogen. Ultrasonography.
Temas:	S Agricultura > SF Cultura de los animales
Unidad académica:	Universidad Católica de Córdoba > Facultad de Ciencias Agropecuarias
Google Académico:	Ver citaciones
URI:	http://pa.bibdigital.ucc.edu.ar/id/eprint/3715

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