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 quail. Peroxyl scavenging capacity decreased in both lines after an acute heat challenge, regardless of acclimation. Finally, fast-growing quail had larger muscle fiber diameters than control quail, and acclimated birds that experienced an acute heat challenge had larger muscle fibers than those that did not experience a heat challenge. Thus, fast-growing quail may physiologically benefit from developing in warmer temperatures.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author