Original scientific paper

Follicular dynamics following induced luteolysis and transvaginal ultrasound-guided aspiration of the largest follicle in dairy cows.

Branko Atanasov ; Faculty of Veterinary Medicine, “Ss. Cyril and Methodius” University in Skopje, Skopje, Republic of Macedonia
Miel Hostens ; Faculty of Veterinary Medicine Gent, Gent University, Gent, Belgium
Irena Celeska ; Faculty of Veterinary Medicine, “Ss. Cyril and Methodius” University in Skopje, Skopje, Republic of Macedonia
Ksenija Ilieska ; Faculty of Veterinary Medicine, “Ss. Cyril and Methodius” University in Skopje, Skopje, Republic of Macedonia
Geert Opsomer ; Faculty of Veterinary Medicine Gent, Gent University, Gent, Belgium
Toni Dovenski orcid.org/0000-0001-9651-2710 ; Faculty of Veterinary Medicine, “Ss. Cyril and Methodius” University in Skopje, Skopje, Republic of Macedonia

Abstract

In practice, many veterinarians inseminate cows ‘blindly’ 72 hours following a single injection of prostaglandin F 2α (PGF 2α). In this paper we describe the results of a study in which we examined follicular growth dynamics following PGF 2α induced luteolysis, aiming at a better insight into the chances for pregnancy when cows are inseminated in a timed manner. A total of 62 dairy cows (CL>25 mm and largest follicle >12 mm) were enrolled in the study and divided over three treatment groups. On day 0 (start of the experiment) all animals received an intramuscular injection of 500 μg cloprostenol, while 42 cows were subjected to ultrasoundguided trans-vaginal follicle aspiration of the largest follicle and were further subdivided into ablation ≤8.5 mm (n = 31) and ablation >8.5 mm (n = 11), according to the size (<8.5 vs. 8.5 to 12 mm, respectively) of the second largest follicle present at the moment of aspiration. The remaining cows (n = 20) were allocated as controls, representing cows that did not undergo follicle aspiration. The duration of follicular growth (DG), follicular growth rates (GR) as well as luteolysis (LL) were estimated in all cows, based on repeated ultrasound examinations and blood analyses of progesterone levels. Duration of growth (days from PGF2α to follicular size ≥15 mm) significantly differed between the cows in ablation ≤8.5 mm and control (5.12 ± 0.23 vs. 3.31 ± 0.21 days) as well as between ablation >8.5 mm and control cows (4.34 ± 0.28 vs. 3.31 ± 0.21 days, P<0.05), whereas no differences were observed between the cows in ablation ≤8.5 mm and ablation >8.5 mm (P>0.05). On the basis of the results of the present study, we conclude that cows bearing a CL and treated with one single luteolytic dose of prostaglandins exhibit large variations in the duration of final follicular maturation as a result of a variety in development status of the follicles present at the time of PGF 2α application.

Keywords

follicular growth; prostaglandin F 2α; luteolysis; cows

Hrčak ID:

140853

URI

https://hrcak.srce.hr/140853

Publication date:

26.6.2015.

Article data in other languages: croatian

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