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

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 (P<0.05) between groups at post-hoc tests from the model presented in Table 1.