Cattle Temperament Effects on Animal Performance Under Grazing.

Temperament in cattle, associated with fear responses to human-animal interactions that commonly occur in cattle production through handling coupled with various management activities, can affect animal performance.  Negative effects on weight gain and carcass quality have been linked to agressive vs. calm cattle, but most of these studies were conducted in feedlot environments.  This study evaluated temperament effect on average daily gain (ADG) of growing cattle grazing different pasture treatments in different grazing experiments.  Temperament was assessed using an average of a subjective (pen score; visual appraisal of each animal ranging from 1= nonagressive, docile, not excited by humans or facilities to 5 = very agressive, excitable, runs into fences and toward humans) and an objective measure (exit velocity; determined as the rate that animals exited the working chute and traversed a fixed distance of 1.83 m).  Across three environments (based a combination of different pasture treatments, sex of animal, and years) calm animals (score < 2.5) had 0.1 kg greater ADG that agressive animals (score > 3.0).  In pasture-based systems, calm animals can be expected to outperform their agressive counterparts.