Origin and characterisation of preovulatory follicles of hyperstimulated oestrous cycles in goats

Simões, J. and Mascarenhas, R. (2007) Origin and characterisation of preovulatory follicles of hyperstimulated oestrous cycles in goats. Acta Veterinaria Hungarica, 55 (2). pp. 259-266. ISSN 0236-6290

Text avet.55.2007.2.12.pdf Restricted to Repository staff only until 30 June 2027. Download (99kB)

Abstract

The origin and evolution of preovulatory follicles (POF) in 9 hyperstimulated (polyovulatory) Serrana goats were characterised. After oestrus synchronisation and detection, transrectal ovarian ultrasonography was performed daily during two complete oestrous cycles. Blood samples were taken every 4 h during 24 h after oestrus detection for preovulatory LH peak and twice a week for plasma progesterone determinations. The interovulatory interval of 14 oestrous cycles with double ovulations was 21.1 ± 0.3 days. The onset of ovulatory follicular wave occurred 4 days (−3.9 ± 0.3 days, n = 14) prior to the ovulation day (day 0) with a POF size of 6.9 ± 0.2 mm (n = 28). In goats with ovulations in both ovaries (78.6%), the emergence of the first POF occurred earlier (−4.1 ± 0.3 days) than the second POF (−3.3 ± 0.2 days, n = 11, P < 0.05). No differences in the total number of follicles ≥ 2 mm were found between the day of POF emergence (4.3 ± 0.4) and the day before ovulation (3.5 ± 0.3, P > 0.05). These results showed the existence of a delay between the emergence of first and second POF and suggest a weak dominance effect in goats with double ovulations.

Actions (login required)

Edit Item