| Abstract | The cohesive behavior (CB) of animals in a small herd or flock can provide an indication of the animals’ ease with their environment and their willingness to explore and efficiently utilize their grazing resources. However, the spatial evolution of CB over time is unknown. The objective of this study was to evaluate CB in a small herd of goats over time. Twenty-one mature, female goats were fitted with GPS collars and released into one of three 0.5 ha wooded paddocks, with seven goats per paddock (replicate). Goats were assigned to the same paddocks each year, unless a substitution was necessary. Collars that recorded a fix every 5-min were deployed for 10 days during the late spring for three consecutive years (max=29°C, min=16°C for year 1; max=24°C, min=13°C for year 2; max=26°C, min=14°C for year 3). The inter-animal distance (IAD), a measure of the CB of the small herd, was calculated for each 5-min interval for animals within the same paddock. A total of 211,156 IAD were available for analysis. To test if CB of the small herds changed over time, that is, day of exposure to the paddock across years, heterogeneity of slopes was evaluated using mixed model methodology with day of exposure to the paddock (1 . . . 10) as covariate, year (1, 2, 3), hour of the day (0 to 23 h), and all two-way interactions as fixed effects and with animal and paddock as random effects. IAD increased linearly with day of exposure to paddock (P < .05) with the greatest increase in years 1 and 3 at 0.83 m/day (SE ± 0.025) and year 2 the slowest at 0.41 m/day (SE ± 0.024). For day 1, the IAD was greatest for year 3 (19.6 m ± 1.37) with years 1 and 2 similar (16.8 m ± 1.43 and 17.1 m ± 1.41, respectively). The IAD was smallest in the early morning hours (23.0 m ± 1.30 at 03:00 h) and greatest shortly after sunrise (29.9 m ± 1.30 at 08:00 h). However, daytime or nighttime had no effect (P > 0.10) upon IAD. These results indicate that a small herd of goats tends to exhibit less CB as time progresses and with familiarity to their environment due to previous exposure. This relaxation of CB might indicate a level of comfort that the small herd has with its environment. |
