Adding chopped straw to concentrate feed: The effect of inclusion rate and particle length on intake behaviour of horses

Physiologically horses have evolved to consume structural herbage, which takes a considerable amount longer to chew than cereals or processed feeds. Previous research has highlighted a significant reduction in chewing rates for concentrate feed As the principal stimulus to saliva production in the horse is mastication, the amount of saliva produced therefore can also be compromised when feeding concentrates, which may influence subsequent digestion as well as buffering within the stomach. Dulphy et al. (1997) observed that the intake rates (dry matter per minute = DM/min) almost halved when comparing hay and straw (14 g and 7.9 g DM/min, respectively), highlighting the effect of physico-chemical composition on chewing efficiency in horses. for buffering stomach contents is also compromised. The inclusion of dried chopped forages or chaff has become popular but there are few published reports on the effects of chaff length or inclusion rate on concentrate feed intake behaviour. The purpose of this experiment study was to investigate the effects of increasing the amount of straw chaff to concentrate pelletswithin a meal on such behaviour of horses.