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Published on: April 25, 2016
Fat digestibility in Equus caballus follows increasing first-order kinetics.
D S Kronfeld1, J L Holland, G A Rich
1Virginia Polytechnic Institute and State University, Blacksburg 24061-0306, USA. kronfeld@vt.edu
Journal of Animal Science
|June 26, 2004
Summary
Equine fat digestibility varies due to feed composition. Low dietary fat content impacts absorption kinetics, potentially affecting vitamin status and benefiting from supplementation.
Area of Science:
- Animal Nutrition
- Digestive Physiology
- Nutrient Metabolism
Background:
- Ether extract digestibility in horses varies significantly across different feed types.
- Previous research attributed variations to non-hydrolyzable substances and endogenous fecal fat.
Purpose of the Study:
- To investigate the factors influencing ether extract digestibility in horses.
- To quantify true digestibility and endogenous fecal fat excretion.
- To identify additional factors affecting fat digestion and absorption.
Main Methods:
- Analysis of 188 equine digestion balance trials with various basal and test feeds.
- Calculation of true digestibility and endogenous fecal fat.
- Statistical modeling to assess the relationship between fat content and digestibility.
Main Results:
- True fat digestibility approached 100%, with endogenous fecal fat at 0.22 g/d/kg BW.
- Non-hydrolyzable substances and endogenous fat did not fully explain digestibility differences.
- A first-order kinetic model (D = 92.0 - 92.0e(-F/342)) accurately predicted digestibility based on feed fat content (F).
- Lower fat content (e.g., 24 g/kg in forages) resulted in approximately 46% digestibility.
Conclusions:
- Fat absorption efficiency is influenced by the rate of lipolysis and substrate concentration in the small intestine.
- Low dietary fat content may limit lipase activity, reducing overall digestibility.
- Fat supplementation could improve vitamin A and E status in horses with low-fat diets.
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