The apparent digestibility of fibre in trotters when dietary soybean oil is substituted for an iso-energetic amount of glucose.

The research article focuses on a study exploring how additional fat intake, in this case, soybean oil, impacts the digestibility of fiber in trotting horses, providing insights with potential implications for the practical feeding of these animals.

Introduction and Methodology

• The study is designed as a 4×4 cross-over trial with feeding periods for each horse lasting 24 days.
• The subjects of the study are eight mature trotting horses, aged between 4 and 12 years, and weighing between 407 to 531 kilograms.
• The feeding regime of these horses comprised of four different diets, that were either rich in soybean oil, glucose, or a combination of both. The amount of hay given to all horses remained constant.
• The energy content of these diets was measured in weight, with the total diets containing 30, 50, 77, or 108 grams of Energy Extract (EE) per kilogram of Dry Matter (DM).
• Despite differences in fat and glucose content, all four diets were identical in all other aspects.

Results and Observations

• An increase of 10 g/kg DM in soybean oil intake resulted in a decrease in the total apparent tract digestibility of crude fiber by 0.9 percentage units.
• An additional fat intake also reduced apparent protein and Nitrogen-Free Extract (NFE) digestibility but increased fat digestibility.

Implications and Conclusion

• Although the results of this study are specific to the conditions and diets used in the experiment, they indicate an interaction between the fat content of horse diet and macronutrient utilization. This could influence practical horse feeding strategies.
• The researchers suggest that when calculating the energy content of high-fat diets based on feedstuff tables, this interaction may cause inaccuracies. This could result in either overestimating or underestimating the amount of energy provided by various diet ingredients.