Meeting Abstract
A high intake of polyunsaturated fatty acids (PUFA) is hypothesized to influence the migratory performance of birds. Current evidence suggests beneficial roles for both n-3 and n-6 PUFA, however it is unclear if the effect is due to PUFA in general or the type of PUFA. We directly tested the effect of diets high in long chain n-3 and n-6 PUFA on flight performance and related indicators of migratory performance in yellow-rumped warblers (Setophaga coronata). The birds were fed diets high in either monounsaturated fatty acids (MUFA), long chain n-3 PUFA, or n-6 PUFA for 6 weeks. During this time, the proportion of 22:6 n-3 and 20:4 n-6 increased in adipose tissue and flight muscles in the n-3 and n-6 PUFA diets, respectively. We assessed endurance flight performance with wind tunnel flights of up to 6h. We found that diet had no significant effect on voluntary flight duration or metabolic flight efficiency. Additionally, no significant differences in basal or peak metabolic rates were found. However, key metabolic enzymes in the flight muscles revealed increased activity of aerobic and oxidative enzymes and decreased anaerobic enzyme activity in the n-6 PUFA group, and the reverse was true in those fed high n-3 PUFA diets. The exact impact of these alterations to migratory performance is unclear. Overall, this study supports the ability of dietary PUFA to modulate muscle physiology, but we were not able to detect any differences to animal performance. The relationship between the metabolic enzymes and endurance flight performance, along with antioxidant capacity and oxidative damage, will also be reported on and discussed in relation to dietary PUFA and testing markers of migratory performance.
