Effect of exercise on apparent total tract digestibility of nutrients and faecal recovery of ADL and TiO2 in ponies.

The research article discusses how exercise affects the apparent total tract digestibility of nutrients in ponies, specifically focusing on faecal recovery of Acid Detergent Lignin (ADL) and Titanium Dioxide (TiO2). The study found that high-intensity exercise can slightly reduce some component’s digestibility and that externally supplemented Titanium Dioxide is a suitable marker for nutrient digestibility, unlike dietary ADL.

Purpose and Method

• The purpose of this study was to investigate if and how exercise affects the apparent total tract digestibility (the proportion of a nutrient ingested that is absorbed and used in the body) of different essential nutrients in ponies, and how exercise influences faecal recovery of Acid Detergent Lignin (ADL) and Titanium Dioxide (TiO2).
• The researchers used six Welsh pony geldings (castrated male horses), which were subjected to either a low-intensity (LI) or high-intensity (HI) exercise regime for 47 days. Digestibility was determined using the total faeces collection (TFC) method. Additionally, ADL and Ti were used as markers to estimate dry matter digestibility (DMD) and organic matter digestibility (OMD).

Findings

• The high-intensity exercise did not affect the apparent digestibility of Crude Protein (CP), crude fat, starch, and sugar. However, there was a decrease in digestibility of dry matter (DM), organic matter (OM), Acid Detergent Fiber (ADF) and Neutral Detergent Fiber (NDF).
• The average faecal recoveries of ADL and Ti were 87.8% and 99.3% respectively. Importantly, Ti was not detected in the urine, suggesting that intestinal integrity was maintained despite the exercise.
• The DMD estimated with the TFC, ADL and Ti for ponies subjected to LI exercise were 66.3%, 60.3% and 64.8%, respectively, while DMD for HI ponies were slightly lower at 64.2%, 60.3% and 65.2%.

Conclusions

• The study concluded that physical exercise can alter the digestibility of Gross Energy (commonly used to measure energy in animal feed) of the feed in ponies with equivalent levels of intake.
• It was also found that external supplementation of Titanium Dioxide is a more suitable marker to determine apparent nutrient digestibility (the percentage of a nutrient that is absorbed from the diet and used for body functions) in exercising horses, compared to dietary ADL, which does not appear to be a reliable marker.