The economics of herd health: costing prevention properly

The economic literature on dairy disease is unusually consistent on one point: the invoice is the small part. Halasa et al. (2007) showed for mastitis that discarded milk, reduced yield, extra labour and culling dominate the total; Liang et al. (2017) reached the same structural conclusion across the main clinical diseases of US dairy herds.

Orders of magnitude worth knowing

• Clinical mastitis: several hundred euro per case once yield loss, discarded milk, labour and culling risk are included (Halasa et al., 2007; Liang et al., 2017).
• Subclinical ketosis: Mostert et al. (2018) modelled the average cost per case in the low hundreds of euro, driven overwhelmingly by knock-on disorders and reduced fertility.
• Lameness: Dolecheck & Bewley (2018) reviewed expenditure and loss estimates and found milk loss and reproductive delay outweighing trimming and treatment costs.

These figures should never be transplanted directly. They are structures, not values: adapt the components to your own milk price, replacement cost, labour rate and yield level, and the result becomes defensible.

Build the budget with an honest denominator

A prevention investment is evaluated against the incidence you actually have, not the incidence you fear. That requires a year of consistent recording before the calculation is credible. The sequence Bouvera uses with clients is straightforward: measure incidence, cost a case using your own farm's inputs, estimate the realistic reduction from the intervention using published effect sizes, and compare that against the annualised cost of the intervention.

Where prevention money usually pays best

• Transition-pen space and bunk access — low technology, broad effect across multiple disorders.
• Colostrum process and calf air quality — the returns arrive two years later but compound through the heifer's whole life.
• Milking routine training and time — often free, and among the fastest measurable returns available.
• Recording discipline itself, which is what makes every other investment measurable.

Presenting the case

Lenders and investors respond to the same structure as any capital case: a baseline, a documented intervention, a conservative effect size drawn from the literature, and a sensitivity range. Herd health is one of the few areas of dairy investment where the evidence base is strong enough to do this properly — and doing it properly is usually what turns a prevention plan from an intention into a funded project.