Epidemiology and levers for control of some major diseases in dairy herds

Abstract

Decisions in animal health management depend on a large variety of situations and problems. To illustrate this, seven major diseases of dairy herds were analysed to identify the main limiting factors for the effectiveness of the current control schemes and the perspectives toward better control in the field. Regarding intramammary infections, research directions focus on the development of multivalent vaccines, tools to better select cows to be treated with antibiotics, on-farm intervention methodology and the enhancement of animal resistance via a contribution of genome-wide selection techniques. For gastro-intestinal strongyloses, priority was also given to rational and selective anthelmintic treatments, genetic improvement of innate resistance seeming less a priority than for small ruminants. The control of Mortellaro disease, a locomotor disorder, should receive attention to develop alternatives because of the forecasted ban of the principal disinfectants used for footbaths. Q fever control can be reached by prolonged vaccination of the whole herd and adequate management of parturition hygiene. Johne disease is probably a good candidate disease for genomic selection, especially given the absence of treatment and very effective vaccine and the presence of a quite promising background of resistance/resilience. Infection by BVDV seems to be controllable by only sanitary measures, associated or not with a vaccination scheme. Eradication of exotic serotypes of BTV can be reached by targeted surveillance and quick and massive vaccination. Specificities in etiology, epidemiology and control techniques of the diseases under study do not quite allow drawing generic conclusions.