Because the EPG data were not normally distributed, we used the nonparametric Kruskal–Wallis and Mann–Whitney U two-sided tests (α = 0.05). The unit of analysis was the flock's sheep-level median EPG.
The descriptive parameters were the EPG quartiles 1, 2 and 3. Statistical significance was considered when P < 0.05. All the estimations were done by using the SPSS statistical package (version 11.1).