The control of the reproduction in non-pregnant mares

The authors review the different methods which were ever used for pharmacological and non-pharmacological methods to modify the reproduction in a non-pregnant mare. These methods are influenced both by the seasonally polyoestrus and by the drugs but a few drugs are available on the market and much fewer licenced for horses in Hungarian condition. Based on these factors the key points of the reproduction are: the shortening the duration of the vernal transition period and hastening the first ovulation, induction/synchronisation of the oestrus in the cycling mares, induction of the ovulation in the cycling mares, suppression of oestrus, suppression of the inappropriate lactation and induction of the lactation. To shorten the vernal transition period is the most time-and cost efficient method-instead of the different pharmacological treatments-is an artificial lighting program. The most common therapies for induction/synchronisation of the oestrus in the cycling mares are the prostaglandins. A practical technique for induction of the timed ovulation is to administer human chorio-gonadotropin and anticipate ovulation about 36 hours later. There are many non-pharmacological alternative methods for suppression of behavioural oestrus but the feeding of altrenogest is the most useful and effective method. Pretreatment of the mares with oestradiol before initiation of dopamine antagonist administration increases prolactin secretion for induction of lactation in a nurse mare. Although there is no information about pharmacokinetics and description of the oral bromocriptine use in horses, being a therapeutic option for inappropriate lactation treatment in mares, it was effective.