A method to estimate digestible energy in horse feed.

Predicting digestibility is a basic step for energy evaluation in horse feed. In horses, as in all species where microbial fermentation plays an important role in digestion, interactions between feed ingredients are even more important than those in other species. In horses suggestions for systems of energy evaluation usually refer to all feedstuffs and they are not limited to certain life stages or groups. It is quite common that the same mixed feed may be used for a leisure horse and a performance horse but in very different rations. Under these conditions it is not surprising that interactions between feedstuffs are widely neglected in predictive equations for digestible energy (DE). Several equations have been suggested that work quite well in some situations and lead to considerable errors in others (1,2). In our investigation we wanted to establish a predictive equation for DE on the basis of proximate nutrients with defined limitations for validity. The equation was derived mathematically from equations based on physiological considerations.