| The objective of this study was to determine the effect of the supplementation of differing sources of dietary long-chain polyunsaturated omega-3 fatty acids on health and performance parameters of exercising horses. Twenty-four horses were used in a repeated 3 x 3 Latin square design with 21-d periods. During each period each horse received one of three diets that differed in omega-3 fatty acid profiles: a soybean oil source (SOY), a flaxseed oil source (FLAX), or an algae source (ALG). Horses were exercised 5 d/wk for a minimum of 20 min, with body weights and body condition scores recorded every 7 d, while blood samples, heart rates, and stride lengths were measured on days 0, 21, 42, and 63. Blood samples were analyzed for various inflammatory markers and for a complete plasma fatty acid profile. Heart rates were recorded during a 30-min exercise bout and stride lengths were measured at the walk and trot before and after exercise. No treatment differences were observed for stride lengths, heart rates, total plasma omega-3, omega-6, and docosahexaenoic acid concentrations, or several inflammatory markers measured in plasma and serum. Plasma eicosapentaenoic acid concentrations were higher in horses on the SOY diet (0.45 +/- 0.07 percent of total plasma lipid) than horses on FLAX and ALG (P < 0.05) and plasma &agr;-linolenic acid was altered in response to treatment (P < 0.05) with horses on FLAX having the greatest percentage. Serum interleukin-10 concentrations were lower in SOY than in ALG (P < 0.05). The results of this study indicate that mature exercising horses free from osteoarthritis do not exhibit physiological anti-inflammatory benefits when supplemented with a low dose of omega-3 fatty acids over a 21-d period. |
