The influence of lameness and individuality on movement patterns in sheep.

We investigated how individuality and lameness altered social organisation by assessing food-directed movement patterns in sheep. One hundred and ninety-six mature Merino ewes were walked in 16 different runs around a 1.1 km track following a food source. Flock position and lameness were measured and temperament was assessed using an Isolation Box Test. The mean value for the correlations of position between a run and the run preceding it was r = 0.55 ± SEM 0.03. All correlations between runs were positive (r = 0.08-0.76) and all but two were statistically significant (P < 0.05). The weakest and least statistically significant correlations were for run 14: where all 16 runs were conducted approximately 3 times a week, except with an interval of 20 weeks between runs 13 and 14. Additionally, there were differences in overall positions for a lame versus a non-lame individual (all P < 0.05) with lame sheep being further back in position when compared to their non-lame mean positions. These results indicate the movement patterns, as measured by flock position during a food-directed forced movement order are relatively stable provided tests occur frequently, possibly on a bi-weekly basis. However, further work will be required to better account for individual animal variation.
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