Concentration of MDA-protein adducts (pmol/mg of protein) in relation to a) sampling date and breeding stage and b) breeding stage and sex.

<p>a) Linear regressions are shown (continuous line = before laying; broken line = after laying); b) bars represent mean+s.e.; numbers above bars denote sample size, while letters denote statistically significant differences (<i>P</i><0.05) between groups at <i>post-hoc</i> tests from the model presented in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0048955#pone-0048955-t001" target="_blank">Table 1</a>.</p>