Einfluss von Stute, Zuchtmanagement und Tierarzt auf die Ovulationsinduktion und Fruchtbarkeit von mit dem GnRH-Analog Deslorelinazetat (Ovuplant™) behandelten Stuten.

Abstract

SummaryDuring the 1995 equine breeding season, 14 equine practitioners participated in a field trial to evaluate factors influencing the response to treatment with the short acting implant (Ovuplant TM ) of the GnRH analogue deslorelin, for induction and acceleration of ovulation. Evaluation of 148 individual reports included determination of ovulation (OR), ovulations occurring within 48 hours after treatment , the interval between treatment and ovulation (ITO) and the pregnancy rate (PR). Mare factors evaluated included breed, age, parity, reproductive status and mare management. Other factors examined were month of breeding, method of breeding and sperm characteristics, and the practitioner's contribution considering the share of equine clients in the entire patient base, years in practice, and reliability and precision in reporting. Neither breed, nor age nor parity had any influence on the effects of Ovuplant. Maiden mares had the longest ITO (51.9 ±19.5 h) and lactating mares the shortest (40.0 ±11.0 h), with a mean of 44.5 h for all mares. Mare management (breeding of single mares, of mares in stud farms or at breeding stations) had no influence on the treatment effect but mares bred at those breeding stations had low PR rates of 46.9% vs. 57.1 (single mares) and 68.5% (mares at stud farms), respectively. Month of breeding (January to October) had no significant effect on the response to treatment. Insemination with fresh semen resulted in the lowest PR (51.5%), with frozen/thawed semen and natural breeding the PR was 65.0% and 64.7%, respectively, and the PR overall was 57.5%. Differences between veterinarians were highly significant for ITO, approached significance for OV-48 and was again significant for OR with treatments of mares with follicles <30 mm and above. Number of mares treated per participating practitioner had no effects, but the share of horses in the entire client base significantly influences OV-48 for those with only 30% equine clients. Simultaneously, ITO was higher and PR lower. ITO was also influenced by years in practice, with highest values for those longest in practice. Response rates regarding OV-48 and ITO varied significantly between practitioners, and reliability regarding ITO as well. der Deckung/Besamung, der Samenart und der Anzahl der Besamungen pro Rosse charakterisiert. Der Beitrag der Tierärzte wurde anhand des Anteils an Pferdebesitzern am Gesamtklientel, der Dauer ihrer Berufsausübung sowie der Glaubwürdigkeit und der Genauigkeit ihrer Berichte beurteilt. Weder Rasse noch Alter und Anzahl der Trächtigkeiten hatten einen Einfluss auf die Wirksamkeit von Ovuplant. Maidenstuten wiesen ein signifikant längeres ITO (51,9 ±19,5 h) im Vergleich zu laktierenden Stuten (40,0 ±11,0 h) auf (P<0,05). Der Durchschnitt aller Stuten betrug 44,5 Stunden. Die Aufstallung der Tiere (Einzeltiere, Gestüte, Deckstationen) hatte ebenfalls keinen Einfluss auf den Erfolg der Ovulationsinduktion; aber die in Deckstationen besamten Stuten wiesen niedrigere PR (46,9 %) gegenüber in Einzelhaltung...