Effects of ovum pick-up frequency and FSH stimulation: a retrospective study on seven years of beef cattle in vitro embryo production.

in Reproduction in Domestic Animals (2008), 43(2), 239-245

The aim of this retrospective study was to compare the number of follicles, cumulus oocyte complexes (COCs) and cultured In Vitro Produced (IVP) embryos obtained from 1396 non-stimulated Ovum Pick-up (OPU ... [more ▼]

The aim of this retrospective study was to compare the number of follicles, cumulus oocyte complexes (COCs) and cultured In Vitro Produced (IVP) embryos obtained from 1396 non-stimulated Ovum Pick-up (OPU) sessions on 81 donor animals in a twice weekly OPU scheme. Results were obtained from 640 sessions following FSH-LH superstimulation, on 112 donors subjected to OPU once every 2 weeks. The stimulation protocol started with the insertion of an ear implant containing 3 mg norgestomet (Crestar, Intervet, Belgium) 8 days before puncture (day -8). The dominant follicle was ablated by ultrasound-guided follicle puncture on day -6. On day -3 and day -2, cows were injected with FSH (Ovagen, ICP) twice daily (8 am to 8 pm), i.e. a total dose of 160 mug FSH and 40 mug LG per donor per stimulation cycle. Animals were punctured 48 h after the last FSH injection (day 0). Progesterone implants were removed the next day. Stimulated donor cows were treated with this protocol at 14-day intervals. Follicles were visualized with a Dynamic Imaging ultrasound scanner, equipped with a 6.5 MHz sectorial probe. Follicles were punctured with 55 cm long, 18 gauge needles at an aspiration pressure corresponding to a flow rate of 15 ml/min. Cumulus oocyte complexes were recovered and processed in a routine IVF set-up. Results demonstrate that, expressed per session, FSH stimulation prior to OPU increases production efficiency with significantly more follicles punctured and oocytes retrieved. However, when overall results during comparable 2-week periods are considered (four non-stimulated sessions vs one stimulated), more follicles are punctured and more oocytes are retrieved using the non-stimulated protocol. No significant differences in the number of cultured embryos could be detected, indicating that FSH/LH stimulation prior to OPU might have a positive effect on in vitro oocyte developmental competence as more embryos are cultured with less, presumably better-quality, oocytes [less ▲]

Application de la GnRH au traitement de l'infertilité chez la vache

Conference (2007, December)

Ultrasonography and bovine reproduction

Scientific conference (2007, February)

University of Liège : general présentation

Scientific conference (2007, February)

Les kystes ovariens dans l'espèce bovine. 1. Définitions, symptômes et diagnostic

in Annales de Médecine Vétérinaire (2007), 151

An ovarian cyst is classically defined as a fluid-filled space larger than 24 mm, that can persist for more than 7 to 10 days in the absence of a corpus luteum. The frequenc y of this pathology is between ... [more ▼]

An ovarian cyst is classically defined as a fluid-filled space larger than 24 mm, that can persist for more than 7 to 10 days in the absence of a corpus luteum. The frequenc y of this pathology is between 7 to 15%. Contrary to the follicular cyst, the luteinised follicular cyst is characterized by the presence in its periphery of a luteal tissue. The ovarian cyst is a dynamic structure. Its presence doesn't interfere with the follicular waves but can modify their characteristics. An ovarian cyst results from or induces an absence of ovulation. Ovarian cyst diagnosis and especially the differential diagnosis between follicular and luteal cysts necessarily imply the use of ultrasonography to clearly identified their diameter and thickeness. The ultrasonography sensibility is better than that of transrectal palpation. Progesteronemia interpretation supposes the preliminary definition of a threshold. Behavioural(anoestrus or nymphomany), uterine(tonicity of the uterine horns) or vaginal (mucus) abnormalities can help to direct the diagnosis. [less ▲]

Le rôle de la machine à traire dans l'apparition des mammites

in Hebdo Vétérinaire (2007), 205

Les mammites ont toujours une origine multifactorielle. Dans ce cadre, la machine à traire est un point critique. Cet article (1re partie) en analyse l’impact dans la gestion de l’élevage, et les ... [more ▼]

Les mammites ont toujours une origine multifactorielle. Dans ce cadre, la machine à traire est un point critique. Cet article (1re partie) en analyse l’impact dans la gestion de l’élevage, et les observations à effectuer pour repérer un dysfonctionnement ou constater une inadéquation entre l’appareil et les animaux traits. [less ▲]

Applications de l’échographie en reproduction équine

Scientific conference (2006, June)

GnRH and bovine reproduction

Scientific conference (2006, March 14)

Etude écopathologique des facteurs de risque des mammites dans les élevages laitiers en Wallonie

Poster (2006)

La mammite a de multiples origines et est souvent de type subclinique, rendant contrôle et surveillance difficiles. La majorité des études relatives aux mammites se caractérise par une approche ... [more ▼]

La mammite a de multiples origines et est souvent de type subclinique, rendant contrôle et surveillance difficiles. La majorité des études relatives aux mammites se caractérise par une approche individuelle. Le cadre expérimental restreint de celles-ci ne permet pas une interprétation précise des observations, à la suite du nombre limité de facteurs étudiés. L’approche choisie pour cette étude se veut globale et implique un grand nombre d’exploitations. Elle a pour objectifs d’identifier et de hiérarchiser, au travers d’une enquête, les caractéristiques générales de traite et les conditions environnementales des élevages laitiers influençant le statut sanitaire du pis [less ▲]

Effets potentiels du stress sur les performances de reproduction en élevage bovin

in Annales de la Faculté de Médecine Vétérinaire de l'UNILU (2006), XVII(1), 26-31