A preliminary study on feeding straw to horses and its effects on equine chewing and consumption rates

Straw as a forage source has been investigated with regards to managing obese horses. However, its effect on chewing rate (CHR) and consumption rate (CR) lacks convincing evidence to encourage its inclusion. In this 2×7-day crossover study, the CHR (chews/5 mins) and CR (kg/hour) of eight horses were analyzed for differences in response to two diets: 50% oat straw, 50% haylage (S) and 100% haylage (CON). On Day 1, CR with S was lower compared to CON (p > 0.05), and by Day 7, this decrease was statistically significant (p = 0.018). CHR was lower on S on Day 1 than CON but higher on Day 7 (p > 0.05). The results suggest that oat straw provided at 50% of the forage ration slows consumption and alters chewing behavior in favor of managing obese horses. Adding oat straw to the forage diet can potentially improve the welfare of horses with low-energy requirements.