700. Detection of genetic variability in cattle infectivity for bovine tuberculosis (bTB)

Bovine tuberculosis (bTB) is a zoonotic disease primarily affecting cattle and leading to important economic losses. Eradication programmes in various countries focus on surveillance, movement restrictions and culling, with some considering also selective breeding. These breeding strategies focus on reducing animal susceptibility to the disease and thus, the potential of reducing disease transmission by selecting also animals with low infectivity remains unknown. The first step in assessing this potential is to detect underlying genetic variation in infectivity. In the present study, the number of secondary cases attributed to a given index case in a breakdown was used as an infectivity phenotype, and a range of linear and<br/>generalised linear mixed sire models were used to estimate its genetic variance and heritability. Substantial genetic variance was detected for this trait, suggesting that infectivity can be reduced via selective breeding, hence contributing to more efficient eradication strategies.