Dietary antioxidants and flight exercise in female birds affect allocation of nutrients to eggs: how carry-over effects work

Abstract

Physiological challenges during one part of the annual cycle can carry over and affect performance at a subsequent phase, and antioxidants could be one mediator of trade-offs between phases. We performed a controlled experiment with zebra finches to examine how songbirds use nutrition to manage trade-offs in antioxidant allocation between endurance flight and subsequent reproduction. Our treatment groups included (1) a non-supplemented, non-exercised group (control group) fed a standard diet with no exercise beyond that experienced during normal activity in an aviary; (2) a supplemented non-exercised group fed a water-and lipid-soluble antioxidantsupplemented diet with no exercise; (3) a non-supplemented exercised group fed a standard diet and trained to perform daily endurance flight for 6 weeks; and (4) a supplemented exercised group fed an antioxidant-supplemented diet and trained to perform daily flight for 6 weeks. After flight training, birds were paired within treatment groups for breeding. We analyzed eggs for lutein and vitamin E concentrations and the plasma of parents throughout the experiment for non-enzymatic antioxidant capacity and oxidative damage. Exercised birds had higher oxidative damage levels than non-exercised birds after flight training, despite supplementation with dietary antioxidants. Supplementation with water-soluble antioxidants decreased the deposition of lipid-soluble antioxidants into eggs and decreased yolk size. Flight exercise also lowered deposition of lutein, but not vitamin E, to eggs. These findings have important implications for future studies of wild birds during migration and other oxidative challenges.

A hidden cost of migration? Innate immune function versus antioxidant defense

“…To investigate whether UA‐corrected AOX and MDA concentration were related with BKA in migrants, but not residents, we used general linear models with status (migrant or resident), BKA, and their interaction as independent variables. In birds, markers of the oxidative balance may show diurnal variations, vary with fat stores, and differ among age classes and between the sexes (e.g., Alonso‐Álvarez, Pérez‐Rodriguez, García, Viñuela, & Mateo, ; Eikenaar et al., ; Jenni‐Eiermann et al., ; Skrip, Seeram, Yuan, Ma, & McWilliams, ; Skrip et al., ; Van de Crommenacker, Komdeur, Burke, & Richardson, ). To take into account, their potentially confounding or masking effects, time of capture, fat score, age (1st year or adult), and sex were entered as covariates into all models.…”

“…Álvarez, Pérez-Rodriguez,García, Viñuela, & Mateo, 2010;Eikenaar et al, 2017;Jenni-Eiermann et al, 2014;Skrip, Seeram, Yuan, Ma, & McWilliams, 2016;Skrip et al, 2015;Van de Crommenacker, Komdeur, Burke, & Richardson, 2011). To take into account, their potentially confounding or masking effects, time of capture, fat score, age (1st year or adult), and sex were entered as covariates into all models.…”

The effects of dietary linoleic acid and hydrophilic antioxidants on basal, peak, and sustained metabolism in flight‐trained European starlings

“…The potential for reduced performance is particularly high for individuals with high tissue PUFA concentrations, due to elevated risk of peroxidation (Hulbert, ; Skrip & McWilliams, ). Dietary antioxidants have been proposed to relieve these tradeoffs (Catoni, Schaefer, et al, ; Larcombe et al, ; Skrip et al, ), by either enhancing preparation for oxidative stress or speeding recovery and preventing the accumulation of damage (Beaulieu & Schaefer, ). Faster recovery and reduced damage to metabolically active tissues could result in greater oxidative capacity and endurance, manifested in higher peak metabolic rates or longer flight durations.…”

“…, investment in reproduction (Royle, Surai, & Hartley, 2003;Skrip, Seeram, Yuan, Ma, & McWilliams, 2016), reproductive hormones and behavior (Carbeck et al, 2018), and ability to meet the oxidative costs of flight (Larcombe et al, 2008;. However, as with fatty acids, results have differed among studies that used different measures of performance and that supplemented diets with different antioxidants, with hydrophilic antioxidants being largely untested (Cooper-Mullin & McWilliams, 2016).…”

“…Dietary antioxidants are also important micronutrients for birds, in general (Klasing, ), and for birds in migration, specifically (Alan, McWilliams, & Mcgraw, ; Bolser et al, ). Functionally, dietary antioxidants act to reduce oxidative damage (Beaulieu & Schaefer, ; Catoni, Peters, & Schaefer, ; Skrip & McWilliams, ), as well as influence immune function (Catoni, Schaefer, & Peters, ; Marri & Richner, ), investment in reproduction (Royle, Surai, & Hartley, ; Skrip, Seeram, Yuan, Ma, & McWilliams, ), reproductive hormones and behavior (Carbeck et al, ), and ability to meet the oxidative costs of flight (Larcombe et al, ; Skrip et al, ). However, as with fatty acids, results have differed among studies that used different measures of performance and that supplemented diets with different antioxidants, with hydrophilic antioxidants being largely untested (Cooper‐Mullin & McWilliams, ).…”