Summary

The spring transition period in mares currently requires significant managerial input to ensure early pregnancies and to reduce inefficient use of stallions. This phenomenon, a phase that all mares progress through each spring, usually lasts 6 to 8 weeks. Currently the most effective treatment is to place mares under artificial lighting from mid-July, followed by hormonal treatments once follicle activity commences. However, no treatments reduce the duration of the transition period or make it easy to predict when the first fertile ovulation of the season might occur. Thus, better methods are required to manage the transition period.

This project proposes to investigate a novel treatment for management of the transition period involving the use of a recently identified neuropeptide called kisspeptin. In this study we will investigate whether the administration of kisspeptin can reduce the duration of spring transition and assist with prediction of the first fertile ovulation for the season. There will be two groups of animals. Group 1 animals will be treated during late spring transition with an infusion of human kisspeptin. Group 2 animals will be treated with a saline infusion as a control. For operational reasons we can only work with eight horses at a time and so to obtain a total of eight/group, four animals from each group will be treated in each of two successive transition periods. The duration from commencement of treatment to first ovulation will be monitored.

The immunohistochemical study included in the preliminary submission has been removed in light of the concerns in the feedback from the RIRDC panel. Instead we have boosted the size of the kisspeptin infusion study to increase the statistical power.

Program

Thoroughbred Horses

Research Organisation

Charles Sturt University

Objective Summary

Gain preliminary evidence as to the feasibility of using kisspeptin treatments as a means of managing the seasonal transition period in mares.