Effect of Hay Soaking Duration on Metabolizable Energy, Total and Prececal Digestible Crude Protein and Amino Acids, Non-Starch Carbohydrates, Macronutrients and Trace Elements.

The study investigates how the length of time hay is soaked in water impacts its nutritional value. The results indicate overall nutrient reduction since essential elements including crude proteins, amino acids, carbohydrates, and others are washed away, which could negatively affect horse health, particularly those suffering from Equine Asthma (EA) or Equine Metabolic Syndrome (EMS).

Research Purpose

• The research aimed to understand the effect of different soaking durations on the nutrient content of hay, including water-soluble carbohydrates (WSC), macronutrients, and trace elements.
• The study also sought to measure the prececal digestible crude protein and amino acid content, as well as prececal digestibility rates across various soaking times.

Methodology

• Four batches of meadow hay were soaked in water at a temperature of 20°C for 0 minutes, 15 minutes, 30 minutes, 60 minutes, and 12 hours, and subsequently drained for 20 minutes.
• The researchers then measured for various nutritional elements including metabolizable energy, digestible crude protein, amino acids, WSC, macronutrients, and trace elements.

Research Findings

• The research found that a soaking duration of 15 minutes significantly reduced the levels of nearly all investigated nutrients, including fructans, WSC, macronutrients, and trace elements.
• The metabolizable energy content decreased by 5-15%, digestible crude protein and amino acid volume fell by 35%, and prececal digestibility declined by up to 49%.
• However, different elements like crude fiber, acid detergent fiber, and acid detergent lignin content were observed to increase.
• This study also found that longer soaking durations did not enhance the wash-out effect, meaning these nutrients were not further depleted with additional soaking time.

Implications and Conclusions

• These findings imply that horse owners must be aware of the possibility that soaking hay, regardless of the reason, may decrease its nutritional value. Thus, it could potentially harm the health of the horse, especially for individuals with specific health conditions like EA or EMS.
• Due to the wide-ranging effects, correctly calculating the right measure of dry matter to prevent weight loss, maintain required metabolizable energy, and fulfill protein and amino acid requirements could become challenging.