Should Horse Owners Steam or Soak Hay?

Steaming and soaking hay reduces respirable dust and mold particles and may decrease the amount of nonstructural carbohydrates ingested by horses. Despite being studied in the past, it remains unclear whether steaming or soaking is better for horses.

To delve deeper into the nutritional and palatability merits of steaming versus soaking, a group of Canadian researchers^* recently fed 13 Standardbred racehorses first-cut timothy-alfalfa hay that was fed as-is, steamed for 60 minutes, or soaked for 30 minutes. Horses were offered various combinations of the dry, steamed, and soaked hay to assess consumption preference and glycemic responses (as a measure of insulin sensitivity). All three types of hay were also analyzed by a local laboratory for macro- and micronutrient composition.

The study revealed:

• Soaked hay had lower concentrations of soluble proteins, nonstructural carbohydrates, and potassium compared to dry hay. No difference in these variables was noted between steamed and dry hay;
• The glycemic responses of horses did not change based on type of hay consumed; and
• Horses much preferred dry or steamed hay compared to soaked hay.

The researchers suggested that the loss of nutrients from soaked hay can be highly variable and dependent on factors such as hay type and maturity. Further, because horses prefer sweet tastes, removing the sweet, nonstructural carbohydrates likely decreased its palatability.

Considering the collective data, the researchers concluded that with the combination of nutrient losses together with decreased intake, soaking could be “detrimental to a horse with high nutrient demands” such as a performance horse.

Preparing the hay, therefore, depends largely on the individual horse. “For horses with dust-reducing needs, steamed hay appears more beneficial, whereas animals with endocrinopathies like metabolic syndrome would benefit more from soaking to decrease nonstructural carbohydrates,” advised Crandell.

Regardless of the intent of steaming or soaking, forage analysis better arms owners with the knowledge they need to guarantee their horses’ diets remain complete and balanced. Some horses may require a vitamin and mineral supplement to ensure their nutrient requirements are satisfied.

*Owens, T., M. Barnes, V. Gargano, et al. Nutrient content changes from steaming or soaking timothy-alfalfa hay: Effects on feed preferences and acute glycemic response in Standardbred racehorses. Journal of Animal Science 97:4199-4207.