Genetic (co)variance and plasticity of behavioural traits in Lidia bovine breed

Scores for four behavioural traits - aggressiveness, ferocity, face hiding and nobility - recorded between 1984 and 2010 in Lidia bovine breed (he property of a single breeder in Spain), were analysed using the multi-trait and reaction norm models. The multi-trait analysis results revealed heritability values of between 0.23 for nobility and 0.33 for ferocity. Principal components analysis of the genetic correlation matrix identified two factors that explained 91.6% of the total variance. Reaction norm analysis revealed genetic correlation values across sexes and time to be< vertical bar 1 vertical bar; this indicates the existence of an interaction genotype x environment. Plasticity, defined as the difference between breeding values over time periods and across the sexes, can be a useful tool for taking into account the influence of the environment on the breeding goal. This allows this interaction to be managed within the framework of a selection programme. With the exception of aggressiveness, which showed significant plasticity, the behaviour of the traits was robust over time and across the sexes. This methodology therefore allows the detection of groups of animals with more robust or plastic responses, particularly with respect to aggressiveness. The use of plasticity as a selection criterion might be beneficial in Lidia bovine breed breeding programmes.