The effect of dietary fish oil supplementation on exercising horses

Abstract

Ten horses of Thoroughbred or Standardbred breeding were used to study the effects of dietary fish oil supplementation on the metabolic response to a high-intensity incremental exercise test. Horses were assigned to either a fish oil (n = 6) or corn oil (n = 4) treatment. The fish oil (Omega Protein, Hammond, LA) contained 10.6% eicosapentaenoic acid and 8% docosahexaenoic acid. Each horse received timothy hay and a textured concentrate at a rate necessary to meet its energy needs. The supplemental oil was top-dressed on the concentrate daily at a rate of 324 mg/kg BW. Horses received their assigned diet for 63 d, during which time they were exercised 5 d/wk in a round pen or on a treadmill. During wk 1, horses exercised for 10 min at a trot. After wk 1, exercise time and intensity were increased so that at wk 5, exercise time in the round pen increased to 30 min (10 min of cantering and 20 min of trotting) per day. Starting at wk 6, horses were exercised 3 d/wk in the round pen for 30 min and 2 d/wk on a treadmill for 20 min. After 63 d, all horses performed an exercise test consisting of a 5-min warm-up at 1.9 m/s, 0% grade, followed by a step test on a 10% grade at incremental speeds of 2 to 8 m/s. Blood samples were taken throughout exercise. During exercise, horses receiving fish oil had a lower heart rate (treatment x time interaction; P < 0.05) and tended to have lower packed cell volume (treatment effect; P = 0.087). Plasma lactate concentrations were not affected by treatment. Plasma glucose concentrations were not different between groups during exercise but were lower (treatment x time interaction; P < 0.01) for the fish oil group during recovery. Serum insulin tended to be lower in fish oil horses throughout exercise (treatment effect; P = 0.064). There was a tendency for glucose:insulin ratios to be higher for fish oil-treated horses throughout exercise (treatment effect; P = 0.065). Plasma FFA were lower (treatment x time interaction; P < 0.01) in horses receiving fish oil than in horses receiving corn oil during the initial stages of the exercise test. Serum glycerol concentrations also were lower in fish oil-treated horses (P < 0.05). Serum cholesterol concentrations were lower in horses receiving fish oil (treatment effect; P < 0.05), but serum triglycerides were not affected by treatment (P = 0.55). These data suggest that addition of fish oil to the diet alters exercise metabolism in conditioned horses.

Effect of dietary energy source on the plasma parameters of equine athletes trained in a deep water aqua treadmill

“…The training program failed to induce the need for an anaerobic energy supply, and this could also explain the lack of differences in plasma lactate level between fat and starch treatments (Figure 1). A similar conclusion was reached using corn and fish oil supplementation (O'Connor et al 2001). Ultimately, it seems that horses around the age of 7 years and having good fitness express a high activity of lactate clearance to prevent the formation of significant peaks of this metabolite in plasma.…”

“…The quality (fatty acid composition) of the dietary fat source also modifies the glucose metabolism. Fish oil supplementation resulted in lower glucose levels compared to the corn oil fed group (O'Connor et al 2001). As none of the above mentioned experiments applied to sunflower oil treatment of our study, we can only speculate that the plasma glucose lowering effect may depend on the fatty acid composition of the dietary fat.…”

“…Therefore, the preference of energy sources depends on the type, intensity and length of the workload. Several publications demonstrate the effect of carbohydrates and fats as energy sources on various blood parameters in horses Spangfors 1998;O'Connor et al 2001;Treiber et al 2008). Research results show that the training of horses in water could be a good alternative or supplement to conventional training (Nankervis et al 2009;Lindner et al 2010).…”

Omega-3 Polyunsaturated Fatty Acids in Physical Performance Optimization

“…Demaison, Blet, Sergiel, Gregoire, and Argaud (2000) found that rats consuming fish oil had reduced heart rate, aortic flow, and cardiac output due to a decrease in vascular resistance. Similarly, O'Connor et al (2004) found that thoroughbred horses administered fish oil for 63 days had lower heart rates and packed-cell volume during exercise than horses fed corn oil.…”

“…A large number of both experimental and epidemiological studies have since been conducted to examine the effect of consuming fish oil, which contains high amounts of EPA and DHA, on cardiovascular health, with most showing an inverse correlation on morbidity and mortality (Albert et al, 2002;Hu et al, 2002;Lemaitre et al, 2003;Oomen et al, 2000;Rissanen, Voutilainen, Nyyssonen, Lakka, & Salonen, 2000;von Schacky, Angerer, Kothny, Theisen, & Mudra, 1999). The cardioprotective effects of omega-3 fatty acids are ascribed to improvements in various cardiovascular risk factors including a reduction in blood-platelet aggregation (Mori, Beilin, Burke, Morris, & Ritchie, 1997;Phang, Sinclair, Linez, & Garg, 2012), decreased inflammation (Heller, Koch, Schmeck, & van Ackern, 1998;Zhao et al, 2004), enhanced endothelial function (Fleischhauer, Yan & Fischell, 1993), positive changes in blood lipids (Calabresi et al, 2004;Harris, 1989;Herrmann, Biermann, & Kostner, 1995), and decreased blood pressure (Paschos, Magkos, Panagiotakos, Votteas, & Zampelas, 2007;Prasad, 2009).…”