Table 2 Sources of variation in red blood cell velocity. ANOVA models were run using Family, Environment and Family by Environment interaction as the modelled sources of variation. Critical F values for the given degrees of freedom (DF) and the calculated F values are given for Red Blood Cell Velocity in the dorsal vein and artery. Significant F values (p < 0.05) are in bold face and asterisks represent highly significant (p < 0.005) p values.