|dc.description.abstract||Dietary omega-3 polyunsaturated fatty acids have shown substantial benefits in
humans including lowered serum cholesterol, blood pressure and indices of stress. The
caloric and extracaloric benefits of feeding fat supplemented diets to performance horses
are well documented (Webb et al., 1987; Meyers et al., 1989; Julen et al., 1995).
However, omega-3 polyunsaturated fatty acids have not been studied to any great extent.
This study was conducted to determine the efficacy of feeding omega-3 fatty acids on
indices of stress and serum cholesterol in horses.
Nine three- and four-year old horses were assigned to diet treatments according to
sex, age and athletic ability. Concentrate diets consisted of: control (A), fatsupplemented
diet with corn oil (B) and fat-supplemented diet with extruded/expelled
soybean oil (C; N-3). Overall, heart rates were lower in horses fed the fat-supplemented
diets compared to the control diet. On reining and cutting exercise days, heart rates were
lower (P<.05) in horses fed fat-supplemented diets vs. the control diet. There were no
differences (P>.05) in heart rates during exercise on reining and cutting days between
horses fed the two fat-supplemented diets. Recovery heart rates following the SET from the end of exercise to 60 minutes recovery (R), were significantly quicker in horses fed
Plasma cortisol concentrations were lowest in horses fed the soy oil-supplemented
diet and highest in horses fed the corn oil-supplemented diet. Across treatments, plasma
cortisol concentrations during the SET rose due to the onset of exercise and remained
significantly higher (P<.05) than baseline during the SET. Serum cholesterol
concentrations were higher in horses fed corn oil-supplemented diets than in the control
or the soy oil-supplemented diets.
There was no significant change (P>.05) in body weight between horses
consuming these three diets. However, when compared to consuming diets B and C the
horses fed diet A had higher (P<.05) concentrate intakes. There was no significant
difference in hay intake (P>.05) between horses consuming the three diets.||en