Statistical analyses
All data are expressed as mean ± standard deviation (SD). Normality in
distribution of variables was univariate tested and log or square
transformed when necessary to meet normality, after they were
back-transformed for tables and graphics. We used MANOVA and regression
methods to examine our hypotheses on blood hematological and
biochemistry parameters according to sample timing and birds’ age and
sex. In analyses, we standardized hatching dates using the earliest
estimated record of hatching each year as day 1 and the difference
between the earliest record and each subsequent hatch date. Statistica
8.0 software statistical package was used to perform statistical
procedures, and we used an alpha value of 0.05 to assess significance of
results.