Voluntary intake and digestibility of teff hay fed to horses.

This research investigates the nutrient composition, palatability, and digestibility of teff hay harvested at various growth stages and its potential suitability as feed for horses. The results suggest that teff hay, particularly in its early maturity stages, is an appropriate and nutritionally beneficial forage for horses, especially for those that are obese or at risk of metabolic disorders.

Study Design and Methodology

• The researchers used six mature Quarter Horse mares in a replicated balanced Latin square design, which is a method for systematically testing multiple variables.
• The Teff hay was harvested in three different growth stages – boot (early growth), early-heading (mid growth), and late-heading (late growth) – to compare nutrient composition and digestibility across stages.
• The horses were first acclimated to a mix of teff hay maturities for 8 days, followed by a testing period involving a 9-day voluntary dry matter intake (DMI) phase, and a 3-day dry matter (DM) digestibility phase.

Key Findings and Their Implications

• The study found that nonstructural carbohydrates (NSC), a key source of energy for horses, increased in concentration from the boot stage to the late-heading stage, while the concentrations of crude protein (CP), potassium (K), iron (Fe), and manganese (Mn) decreased.
• Horses showed a preference for the earlier maturities of teff hay, consuming less of the late-heading hay. This could impact decisions about when to harvest teff for horse feed.
• The nutrient composition of the boot and early-heading maturities met 90 to 97% of the horses’ average daily energy (DE) requirements and most other nutrient requirements, suggesting they are nutritionally adequate as horse feed.
• Digestibility rates of various elements, such as DM, CP, acid detergent fiber (ADF), and neutral detergent fiber (NDF), decreased from boot to late-heading stages. Conversely, digestibility rates for nonfiber carbohydrates and water-soluble carbohydrates increased across this maturity spectrum. This could have implications for the health and well-being of horses consuming the feed, particularly those with specific dietary needs.
• Importantly, for all maturities of teff hay, the NSC intake was below 10% of total intake. Given that high NSC intake can contribute to obesity and metabolic disorders in horses, teff hay may help mitigate these risks.

Conclusion

• The study concluded that teff hay, especially if harvested in the earlier stages of maturity, is a suitable forage for horses. Its low NSC and DE content make it particularly beneficial for obese horses, or those at risk of laminitis or other metabolic disorders.