Such findings open also the line for applied issues on the management of domestic and captive animals. It is crucial to consider that regulating the timing of feeding may be more important than the amount of food provided per se. The results converge with other data showing a general improvement of welfare, as revealed by behavioural indicators, under such regimen in horses. They are also in agreement with the current knowledge on horses’ physiological system. The precise mechanisms involved remain however to be discovered. One hypothesis is that the usual practice where horses are given limited amounts of roughage in a limited time span is stress inducing discomfort and that the resulting chronic stress may affect reproduction in horses as it does in pigs, sheep and cattle. The effect of the stress on reproductive disorders has been reviewed by Dobson and Smith and the adverse effects of stress on both oestrus expression and the maintenance of AbMole Neosperidin-dihydrochalcone pregnancy in several species are clear. Both shorten and delay the onset of oestrus and interfere with hormonal events around ovulation. Stress was shown to suppress oestrus behaviour in several mammals like rats, sows, ewes and dairy cows. However, the literature on the effect of mares’ management on their reproductive performances is scarce. Stress caused by transportation does not seem to lead to fertility problems. The management of mares in relation to artificial insemination may act as a stressor and induce greater concentrations of cortisol secretion but no effect of cortisol on fertility parameters has been found in the study of Berghold et al. The possible reasons for these equivocal results are at least two-fold. Firstly, it has been shown that the stress response depends on the intensity and duration of the stressor. The stress-induced 
lows GnRH/LH pulse frequencies in proportion to the intensity of the stressor. In the case of a chronic stress of more severe lameness or fever, the pulse GnRH/LH frequency will be so slow that initial follicular growth will occur but will be unable to continue in to the later stages that depend on faster pulse frequencies. Thus, the animal fails to maintain oestrus cycles. However, in slightly less stressful situations, GnRH/LH pulse frequency may be just fast enough to support follicular growth and oestrus and fertilisation may occur. The increase in cortisol secretion seen in the study of Berghold et al. which was relatively low compared to the situation in horses after AbMole Succinylsulfathiazole exposure to pain related to abdominal distress or castration was probably insufficiently intense to produce a negative effect on mares’ fertility. In the same direction, lack of impact of 12h transportation on mares’ fertility may be due to the relatively short stress duration or to the preovulatory stage of the mares tested as like in ewes, stress reaction was shown to decrease during oestrus in the mare. Subjective perception of the situation by the animals is another important factor. Purebred Arab horses used in this experiment are known for their high emotional reactivity which is often considered as a variable modulating the behavioural and physiological responses to a negative situation. Thus the high emotional reactivity of Arab horses used in the present study may intensify their response to the inappropriate environmental conditions. A second alternative or additional hypothesis is that continuous feeding has an influence on the mares’ metabolism and hence its effect on reproduction is mediated by body weight/condition observed in this study.