Breeding Programs to Reduce Foot and Leg Problems

The incidence of foot and leg problems and their direct and indirect consequences can be reduced by selection. The most promising approach is to select on an index that includes at least linear scores for foot angle or diagonal, rear legs rear view, and a locomotion score. Desirable are high foot angles, shorter diagonals, straighter rear legs from the rear with little to no closeness at the hocks, and locomotion scores that reflect easier walking. In some populations legs straighter than average at the hocks as observed from the side may have value. Low frequencies of direct observation of actual foot and leg problems limit their usefulness in selection decisions, but they might improve estimates of Breeding Value if used when they are available. Because the heritabilities of the foot and leg traits are low when based on the phenotype of individual animals, selection will be many times more effective when based on animal model estimates of progeny average breeding values. Antagonistic genetic correlations apparently exist between yields of protein, milk, and fat of first lactations and incidence of foot and leg problems. These indicate that the index used for feet and legs be a subindex or only part of the overall index used for selection of parents of future generations of dairy cattle.