The confinement reactivity (CR) has been used as a measure of temperament in Brazil and it is defined as the animal reaction when contained in the scale. It is quantified through the animal reactivity test - REATEST®. This test consists of an electronic device coupled to the scale and of specific software. The device captures the movement that the animal provokes in the scale, during 20 seconds and sends it for the software that processes this movement and determines the animal CR in a continuous scale of points. Higher punctuations belong to aggressive animals. The CR was created with the goals of to solve the problems existent in the culling for the better temperament and of to estimate genetic parameters more reliable. The CR is objective, has great phenotypic variability and eliminates the appraiser's subjectivity, besides it doesn't expose him to the danger. The CR doesn't interfere in the handling practices of the ranch because it is quantified in the moment of the animals weighting. The CR is quantified in fast and easy way and for your quantification can use any kind of scale. The direct heritabilities estimates are 0.39 at 12 months of age and 0.23 at 15 months of age. The genetic correlations between CR and daily weight gain (DWG) were -0.28 between CR and DWG-birth to weaning and -0.49 between CR and DWG-weaning to 12 months of age. About the genetic correlations between CR and scrotal circumference grown rate was highest, -0.41.
bovine; reatest; temperament
