Feeding straw to horses

Background

Straw has long been used as feed for horses in Sweden and is also recommended for horses that eat quickly and are overweight, as it contains little energy and takes longer to chew than many other types of feed. However, a study of privately owned horses in Denmark found that horses fed straw as their sole roughage had an increased risk of stomach ulcers. The reason for this is unclear and may be due to many factors that could not be controlled in the study. In some European countries, feeding straw is now discouraged.

About this study

The study now published by SLU researchers was a controlled study in which horses were fed two different diets for three weeks each. One diet contained only haylage (control diet) and the other contained 50% haylage and 50% wheat straw. The diets had the same energy content and both diets met all known nutritional requirements.

One of the most important questions in the study was whether feeding straw caused stomach ulcers.

Results

The study showed that a diet in which half of the feed consists of straw of good hygienic quality does not cause more stomach ulcers than if straw is not included in the diet. In the diet with straw, the horses consumed the hay silage first and the straw last, and had longer feeding times and slightly lower energy intake. Analyses of blood samples taken during the study also indicate that the horses had a more even secretion of saliva and other digestive fluids when straw was included in the diet than when it was not. This is probably because they ate faster and more voraciously when they did not receive straw. A voracious eating pattern does not necessarily have to be a problem, but it can increase the risk of oesophageal obstruction in some individuals and it can also be a sign that the horses feel hungrier before feeding.

When the horses were on the straw diet, they also had a slightly higher concentration of the hormone serotonin in their blood plasma, which can increase the feeling of satiety.

Blood tests also showed that they had lower insulin levels on the straw diet, which may be beneficial for horses at risk of developing laminitis. Overall, the study shows that feeding straw as a supplement to other roughage can still be recommended for horses with low energy requirements or when there is a shortage of pasture feed.

The study was funded by the Marie-Claire Cronstedt Foundation.

Link to the article:

Straw as an Alternative to Grass Forage in Horses—Effects on Post-Prandial Metabolic Profile, Energy Intake, Behaviour and Gastric Ulceration