Ovulation and oestrus synchronization using fluorogestone acetate vaginal spong...

• Autor(es): Valentim, Ramiro ; Azevedo, Jorge ; Almeida, José Carlos ; Correia, Teresa Montenegro ; Mascarenhas, R. ; Fontes, Paulo ; Simões, João
• Data: 2006
• Identificador Persistente: http://hdl.handle.net/10198/2850
• Origem: Biblioteca Digital do IPB
• Assunto(s): Fluogestone acetate; Serrana goats; Vaginal sponges
• Tipo de Documento: Documento de conferência
• Idioma: Inglês

Descrição

In order to determine the precise time of induced ovulation and oestrus after progestagen treatment in nulliparous Serrana goats, nine females aged between 2 and 3 years were used. In May, an intravaginal sponge impregnated with 45mg of fluorogestone acetate was inserted for 12 days with the injection (i.M.) of 500UI of eCG and 50 µg of cloprostenol at sponge removal time. Oestrus was detected using a vasectomized buck. Blood samples were collected from the jujular vein of each goat every 4h, during the first 24h after the onset of oestrus for LH determination. A transrectal ultrasond scanning of both ovaries was also performed every 4h, from onset of oestrus to 44h later. Ovulation was detected by disappearance of the large follicles.Corpora lutea (CL) were counted by ultrasonographic observation, 7-10 days after ovulation. The onset of oestrus was identified 33,4± 2.7 h (mean ± SD; n=9 after sponge removal. The interval between sponge removal and preovulatory LH peak was 37.0 ±3.6 h with a minimum of 51.3 and a maximum of 62.3 h The interval between preovulatory LH peak and ovulation was 20.0 ± 3.1 h. The number of CL observed per goat was 3.3 ± 0.7. In conclusion, after this progestagen treatment, a low variation of the time of ovulation was found. The great number of CL suggest a small dose of eCG could be used in nulliprous Serrana goats during seasonal anoestrus.