title: An echographic study of follicular growth during induced estrus in female Azawak zebu in Niger.
abstract: An echographic study of follicular growth up to ovulation was carried out on 42 lactating Azawak cows (Bos indicus) after estrus induction by means of a PGF2α or a procedure involving the administration of progesterone vaginally (PRID® DELTA: progesterone-releasing intravaginal device) for a 10-day period and the injection of a PGF2α and an ECG (400 and 800 IU) on withdrawal. All the animals were inseminated 12 and 24 h after the onset of estrus. The percentage of estrus induced was not significantly different between the two groups of animals (81 %). The average time delay before the onset of estrus was significantly longer after injection of a PGF2α (84.8 ± 26.0 h) than after withdrawal of the PRID® (59.2 ± 5.8 h). The average duration of the estrus was significantly shorter after its induction by PGF2α (12.6 ± 2.6 h) than after induction by progesterone (22.9 ± 2.7 h). There was not a significant difference in the interval between the beginning of estrus and ovulation in animals treated by PGF2α (30.3 h) and progesterone (28.4 h). Injection of a PGF2α was accompanied by a significantly lower rate of gestation than that obtained after treatment of animals by progesterone (31.2 vs 54.5 %). These results confirm the necessity to adapt an insemination policy to hormonal treatment for estrus induction in B. indicus.
authors.affiliation: Faculty of Agronomy, University Abdou Moumouni, Niamey, Niger. moussagarba2@yahoo.fr.
authors.forename: Mahamadou Moussa
authors.initials: MM
authors.lastname: Garba
authors.affiliation: Faculty of Agronomy, University Abdou Moumouni, Niamey, Niger.
authors.forename: Moumouni
authors.initials: M
authors.lastname: Issa
authors.affiliation: Faculty of Agronomy, University Abdou Moumouni, Niamey, Niger.
authors.forename: Hamani
authors.initials: H
authors.lastname: Marichatou
authors.affiliation: Faculty of Veterinary Medicine, Theriogenology Department of Animal Production, University of Liege, B42 Sart Tilman, 4000, Liege, Belgium.
authors.forename: Christian
authors.initials: C
authors.lastname: Hanzen
mesh_terms: D000818:Animals; D002417:Cattle; D015237:Dinoprost / Q000008:administration & dosage; D004971:Estrus / Q000187:drug effects / Q000502:physiology*; D005260:Female; D007315:Insemination, Artificial / Q000662:veterinary*; D007774:Lactation; D009548:Niger; D006080:Ovarian Follicle / Q000000981:diagnostic imaging / Q000187:drug effects / Q000502:physiology*; D010060:Ovulation / Q000187:drug effects / Q000502:physiology*; D011247:Pregnancy; D018873:Pregnancy Rate; D011374:Progesterone / Q000008:administration & dosage; D012098:Reproduction; D014463:Ultrasonography
chemical_list: D011374:Progesterone; D015237:Dinoprost
keywords: Bos indicus; ECG; Echography; Estrus; Ovulation; PGF2α; Progesterone