Growth rate of ovulatory follicles during the first ovulatory oestrus (after seasonal anoestrus) and subsequent oestrous period in Irish Draught mares

Irish Veterinary Journal

Juan Cuervo-Arango²  John R Newcombe¹ 

[1] Equine Fertility Clinic, Warren House Farm, Brownhills WS8 6LS, UK;Departamento de. Medicina y Cirugía Animal, Facultad de Veterinaria, Universidad CEU Cardenal Herrera, Moncada, Spain

关键词: First ovulatory oestrus;    Growth rate;    Follicle;    Mare;    Irish Draught;   

Others  :  810805
DOI  :  10.1186/2046-0481-66-4

 received in 2012-01-09, accepted in 2013-02-07,  发布年份 2013

【 摘 要 】

It is believed that during the spring transition, the developing follicle tends to grow more slowly, persist longer and grow to a larger diameter prior to ovulation than at subsequent oestrus periods. A general suspicion, that the first ovulation of the year is less fertile than subsequent ovulations could be explained by a slower growth rate of the ovulatory follicle during transition with the consequent production of a subfertile oocyte. By detailed serial examination of the same group of Irish Draught mares over three winter/spring periods, no significant difference was found in either growth rate or pre-ovulatory diameter when compared with subsequent ovulations. Mean growth rates over the ten days prior to ovulation were 2.20 mm/day (range 1.18 to 3.64) and 2.19 mm/day (range 1.25 to 3.41) for first and subsequent ovulations respectively. Mean maximum pre-ovulatory diameters were 44.7 mm (range 35 to 59) and 43.5 mm (range 31 to 57.5) for first and subsequent ovulations respectively. The impression gained by practitioners that the first follicle develops more slowly during the transition to the first ovulation of the season may be due to less frequent examinations and consequently a failure to observe and record that follicles may grow and then regress during this period. The largest follicle observed a few days previously is not necessarily the same large follicle found at a later examination.

【 授权许可】

   
2013 Newcombe and Cuervo-Arango; licensee BioMed Central Ltd.

【 图 表 】

Figure 1.

【 参考文献 】

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