Imflammatory response in horses fed diets containing omega-6 and omega-3 fatty acids

Abstract

This study was conducted to characterize the inflammatory response of horses to chronic and acute exercise as influenced by dietary fat supplementation. Different ratios of omega 6 vs. omega 3 fatty acid supplementation were provided in the diets and effects on the inflammatory response were determined. Nine, three and four-year-old horses were fed diets with different sources of fat in a triplicated 3X3 Latin square arrangement of diet treatments. The horses were maintained in a typical reined cowhorse training protocol to mimic the athletic stresses placed on young horses during strenuous exercise. There was no significant difference (P>.05) in body weight between horses consuming the three diets. When compared to consuming diet B (corn oil) and C (soybean oil) the horses fed diet A (control) had higher (P<.05) concentrate intakes, and total feed intake was higher (P<.05) for horses fed diet A than diet B. Horses fed diet A had higher (P<.05) digested dry matter and digested organic matter than horses fed diet B. There were no differences (P>.05) in dry matter digestibility or organic matter digestibility between horses fed the three diets. Fat intakes and digestibilities were higher (P<.05) when the horses where fed diet B and diet C than when fed diet A. When the horses where fed diet A they had higher (P<.05) concentrations and percent change in 14:0, 16:0 and 18:1n-9 fatty acids at d 32. When the horses were fed diets B and C they had higher (P<.05) concentrations and percent change in 18:2n-6. When the horses where fed diet A (P<.05) they had lower concentrations and percent change in 20:4n-3 than when horses were fed diet B. Overall mean fibrinogen concentrations across treatments increased (P<.05) during the training period. When analyzed by diet, fibrinogen concentrations during the training period and following the standardized exercise test were higher (P<.05) when the horses were fed diet B than when they were fed diets A or C. Overall mean serum amyloid A concentrations across treatments increased (P<.05) from the day of the test to 1 day following the standardized exercise test and then decreased to baseline values at d 3 post test.