**5.1.6 Statistics**

First, differences between breed groups for clinical and haematological data were assessed using analysis of variance (ANOVA) by GLM procedure (SAS, 1990). A second ANOVA was carried out only for the Altamurana group, considering the interaction between the alpha globin type (2 levels: NH and EH) and each clinical variable. The last ANOVA was carried out only for the Suffolk group considering the interaction with the beta globin type (2 levels: AB and BB) of the linear and quadratic regression of each haematological variable on the number of days from the infection, with three of the Suffolk that were AB compared to as many BB. This analysis was performed for the Suffolk, where, as cited above, both AB and BB genotypes were found, whereas only BB animals occurred in the Comisana.
