Sole haemorrhages in Danish bull calves: Prevalence and risk factors.

To evaluate the prevalence of sole haemorrhages among Danish dairy breed bull calves and associated risk factors, 730 calves were hoof trimmed shortly before slaughter and the presence of sole haemorrhages was recorded. Associations between the outcomes sole haemorrhages and severe sole haemorrhages, and the explanatory variables daily weight gain, liver abscesses and flooring, were analysed. Of the 730 calves, 545 (74.

Economic figures in herd health programmes as motivation factors for farmers.

Veterinarians often express frustrations when farmers do not implement their advice, and farmers sometimes shake their heads when they receive veterinary advice which is practically unfeasible. This is the background for the development of a focused 3 page economic report created in cooperation between veterinarians, farmers, advisers and researchers. Based on herd specific key-figures for management, the report presents the short- and long-term economic effects of changes in 15 management areas.

Age-structured dynamic, stochastic and mechanistic simulation model of Salmonella Dublin infection within dairy herds.

In the demand for a decision support tool to guide farmers wanting to control Salmonella Dublin (S. Dublin) in Danish dairy herds, we developed an age-structured stochastic, mechanistic and dynamic simulation model of S. Dublin in dairy herds, which incorporated six age groups (neonatal, preweaned calves, weaned calves, growing heifers, breeding heifers and cows) and five infection states (susceptible, acutely infected, carrier, super shedder and resistant).

A stochastic model simulating paratuberculosis in a dairy herd.

Paratuberculosis (PTB) causes severe economic losses to farmers and the infection has very complex effects (many indirect) on the production of a dairy herd. These indirect effects have not or only briefly been described by earlier PTB-simulation models, and therefore they were included in a new model called PTB-Simherd. Our aim was to develop the basis for a decision-support tool which can predict herd-specific production-related effects from introduction of different control strategies against PTB.

Simulated economic effects of improving the sensitivity of a diagnostic test in paratuberculosis control.

Low sensitivity (Se) of diagnostic tools is often mentioned as a major problem in the control of paratuberculosis (PTB) and much effort is put into the improvement of these tests. The hypothetical perspectives of improving the Se of a milk-antibody ELISA (hereafter: milk-ELISA) used in test-&-cull strategies against PTB in dairy cattle were investigated by simulations. The current Se varies between 10 and 80%, increasing with increasing lactation stage, parity and infection stage.