Prediction of the digestibility and digestible energy content of hay for horses using an enzymatic degradability method.

This study investigates the possibility of predicting the nutritional content of hay for horses using an in vitro enzymatic treatment process known as pepsin-cellulase degradability.

Introduction and Objective

• The research aims to provide an efficient alternative to the prevalent in vivo methods that gruesomely involve experiments on live animals.
• The primary objective is to verify if the digestibility value of the organic matter in the hay (OMD), dry matter digestibility (DMD), energy digestibility (ED), and digestible energy (DE) of hay can be estimated through an enzymatic degradability method or a combination of this with other chemical composition parameters.

Methodology

• For the study, the team compiled a database of 43 types of hay harvested in a temperaate zone.
• The types include 32 natural grassland hays, five grass hays, and six lucerne hays.
• All these variations of hays were exposed to the enzymatic method in order to predict their digestibility properties.

Results and Discussion

• The findings showed that the in vitro enzymatic method paints a good picture of the nutritional attributes in practice.
• The range of OMD values varied between 0.42 and 0.63, while the dCS cellulase digestibility fluctuated between 41.0% and 62%.
• It was observed that the prediction models of DMD, OMD, ED, and DE provided consistent results with minimal differences between them. The consistency was quantified with R-values ranging between 0.87 and 0.91.
• A significant conclusion is that adding chemical composition parameters as variables to the prediction models did not significantly improve the predictability of the digestibility. This further supports the viability of the enzymatic method.

Conclusion

• The study concludes that the proposed models can be viable alternatives to in vivo prediction methodologies.
• These methods for predicting the nutritive value and DE content of hay based on purely chemical composition can substantially reduce the dependency on live animal-based testing procedures.