Validating techniques to sample behavior of confined, young pigs

Ten 1-h segments of videotaped behavior served as the population from which behavior was sampled. Half of the videotape segments were behaviors of recently re-grouped and aggressive pigs and the remaining segments were of the later socially-stable groups. Attack, feeding, drinking, lying, moving and standing were recorded. Time-sampling (recording less than the full periods) resulted in acceptable correlations and mean values when sampling periods were greater than 20 min per hour. Focal animal sampling was an accurate sampling technique for all behaviors except attack. Observing videotapes at 4 times faster than life provided an accurate sample of all behaviors, but viewing tapes 24 times faster than life was inaccurate for drinking and feeding behavior. These results highlight the need for validation of sampling techniques for studies measuring pig behavior.