Thermal acclimation of fast-growing quail exhibit decreased oxidative stress and increased muscle fiber diameters after acute heat challenges.

Many predict dire consequences of increasing temperatures, however, high temperatures in early life may aid animals during extreme thermal events later. But, underlying physiological mechanisms have not been elucidated. We examined whether developing in warmer temperatures would physiologically benefit adult quail ( Coturnix coturnix japonica Temminck and Schlegel, 1849), by exploring changes in oxidative stress and muscle structure in two lines of quail– one selected for control growth and another for fast growth and after acute heat challenges. We used a factorial design to administer four treatment combinations to each line: an initial period of either heat-stress acclimation (3 hrs every other day to 37 °C) or no acclimation , and after five weeks, either a heat-stress acute challenge (8 hrs at 39 °C) or no challenge. We found that control quail had significantly higher citrate synthase activity than fast-growing quail. Fast-growing quail had higher hydroxyl scavenging capacity than control quai...