Abstract

Fatty acids, like omega-3s, are often supplemented to horses to increase the caloric density of a diet and to replace soluble carbohydrates. Palatability limitations of omega-3s have led to an interest in alternative sources like Conjugated Linoleic Acid (CLA) that exert health effects similar to omega-3s. However, the effect of CLA on equine body composition has not been established. The purpose of this investigation was to evaluate the effects of dietary CLA supplementation on equine body composition. Nine stock-type horses were stratified by age, body weight, and sex, and randomly assigned to one of two dietary treatments for a 12-wk study. Diets were formulated to be isocaloric and isonitrogenous and consisted of 0.015% BW/d (AF) of CLA (n=5) or soybean oil (n=4; control) that was top-dressed and mixed immediately prior to feeding. Performance measurements were collected weekly; rump fat thickness, Ribeye area, and intramuscular fat were measured on days 0,42, and 84 by a certified technician. The MIXED procedure in SAS was used with repeated measures to detect differences in measurements. There were no differences in performance characteristics or body fat content between treatment groups (P > 0.05). To account for initial differences between treatments (P < 0.05), ribeye area between the 17th and 18th ribs (REA17) was analyzed with day 0 as a covariate. Mean REA17 tended (P < 0.10) to be higher in CLA supplemented horses than controls. Results suggest that CLA does not affect equine body composition, but further study is necessary to elucidate potential benefits of CLA in the horse.

Keywords: Conjugated linoleic acid; Equine; Body composition

Abbreviations: Conjugated Linoleic Acid (CLA); Body Weight (BW); Body Condition Score (BCS); As-Fed (AF); Rump Fat Thickness (RFT); Ribeye Area (REA); Back Fat Thickness (BF); Intra Muscular Fat (IMF)