A minimum of roughage and a maximum of starch necessary benchmarks for equine diets

Abstract

The rations for modern leisure or performance horses are hardly influenced by the tradition of feeding horses doing farm work or serving in public infrastructure and industry as hard working animals. Typically roughage is limited and concentrates are dosed to balance the caloric needs. However, limitations in roughage are in conflict with the time budget of the horse today as it is not full time exercised. The adual roughage management often neglect the perspectives of this feed to contribute to energy and nutrient intake even in performance horses4 Data on diets for 3-day eventers confirm the suitability of rations high in roughage. The huge impact of roughage on saliva production, speed of feed intake and - possibly the most important link - on behaviour requires to define this part of equine diets by the recommendation of feeding daily min 15 g roughage/ kg body weight (defined as as feed of 88 % dry matter). This amount will even at low feeding levels cover the caloric needs for maintenance. High starch intake changes the baderial community in the entire digestion tract. This is in principle accepted as a risk factor for gut health. Consequently a limitation in starch intake is an essential factor in safe rationing. But two further factor need to be included for deriving a starch limitation. Glucose as the proctud of starch digestion induces an insulin response. In case of high starch intake this response is enforced and charaderized by a persistency of insulin adivities in blood distindly above base levels, a situation which is in conflict to the preferential status of a horse prior exercise. Additionally epidemiological data identify high starch intake a a risk factor for the development of gastric lesions/ulcers. These facts are recognized by the recommendation to limit starch intake per meal at 1 g/kg body weight.