Inducing weight loss in native ponies: is straw a viable alternative to hay?

Background Obesity is a growing problem in UK equine population. Achieving weight loss in obese horses and ponies at risk of laminitis is an important but often challenging objective. Methods We hypothesised that supplementing poor winter pasture with a mix of barley straw and hay (50:50) rather than hay alone (group B) would lead to weight loss in grazing equids over winter. For this purpose, a group of 40 horses were fed either the straw mix (group A) or hay alone (group B) over winter. Results Over the study period, all animals in group A (n=25) lost weight with a mean weight change of -27 +/- 17 kg, while in group B (n=15) only 3 out of 15 lost weight (20 per cent), and overall, group B gained weight (+6 +/- 18 kg). Conclusions This study suggests that straw is a cost--effective and low-energy roughage, which may be a useful alternative to hay alone when trying to induce weight loss in grazing equids over winter. There were no episodes of colic or laminitis during the study period in either group.