Skip to Main content Skip to Navigation
Conference papers

Influence de la durée d’un traitement progestatif sur la dynamique de croissance des follicules préovulatoires induits par effet mâle chez la brebis Ile de France en anœstrus saisonnier

Abstract : In order to investigate the effect of the duration of progesterone treatment (12 vs. 2 days) on the growth of the pre-ovulatory follicle induced by ram exposure, an experiment was conducted during the anestrous season in 41 anovulatory ewes of the “Ile de France” breed with 9 sexually active males. The ewes were divided into three homogenous groups: Control group (n=20) received no hormonal treatment, CIDR-2 group (n=11) received a short-term progesterone treatment (intravaginal progesterone release device CIDR for 2 days) and CIDR-12 group (n=10) received a long-term progesterone treatment (CIDR for 12 days), before the introduction of the ram. CIDR was removed 24h before ram introduction (D0). Estrous behavior was recorded twice daily from day 0 to day 4. The quality of the induced cycle (short or normal cycle) was determined based on plasmatic progesterone profiles over 25 days after the ram effect (blood sampling once a day). The parameters of growing dynamics of pre-ovulatory follicles were also analyzed (day of emergence, size at D0, day of ovulation, ovulatory size, the time for follicular growth, growth rate and follicle lifespan) by transrectal ultrasonography. The results show that the duration of the progesterone treatment had no effect on the proportion of ewes ovulating (98%). As expected, all CIDR-treated ewes which ovulated developed a normal cycle. In contrast, most of the ewes from the control group developed a short cycle (80%). Estrous behaviour was observed in all ewes from the CIDR-12 group but only in 2 ewes from the CIDR-2 group. No ewes from the control group exhibited estrous behaviour. The time for follicular growth was greater (P=0.003) in ewes treated with progesterone for 12 days (4.4 ± 0.3 days) than in ewes treated for 2 days (3.2 ± 0.3 days) and untreated ewes (2.9 ± 0.2 days). In the same way, the lifespan was longer (P=0,01) in the CIDR-12 group (5.7 ± 0.3 days) than in the CIDR-2 group (5.1± 0.4 days) and Control group (4.3 ± 0.3 days).These observations were related to the time of ovulation, which occurred later (P=0.08) in the CIDR-12 group (3.2 ± 0.7 days) than in the CIDR-2 group (2.4 ± 0.3 days) and Control group (2.6 ± 0.2 days). However, the other parameters did not differ among groups. These results suggest that a long-term progesterone treatment prior to ram exposure leads to a better maturation of preovulatory follicles induced to ovulate.
Document type :
Conference papers
Complete list of metadata

https://hal.inrae.fr/hal-02749225
Contributor : Migration Prodinra Connect in order to contact the contributor
Submitted on : Wednesday, June 3, 2020 - 2:57:02 PM
Last modification on : Thursday, August 5, 2021 - 3:46:56 AM

Identifiers

  • HAL Id : hal-02749225, version 1
  • PRODINRA : 179267

Collections

Citation

Achraf Adib, Sandrine Freret, Didier Chesneau, Jean-Luc Touze, Philippe Chemineau, et al.. Influence de la durée d’un traitement progestatif sur la dynamique de croissance des follicules préovulatoires induits par effet mâle chez la brebis Ile de France en anœstrus saisonnier. 19. Rencontres autour des Recherches sur les Ruminants, Institut de l'Elevage (IDELE). Paris, FRA. Institut National de la Recherche Agronomique (INRA)., Dec 2012, Paris, France. ⟨hal-02749225⟩

Share

Metrics

Record views

16