A new costing model has been published that can estimate when a prevention strategy can pay back for reducing lameness incidence. For infectious disease such as Digital Dermatitis (DD), incidence rates generally need to be 40% or over and strategies need to reduce incidence by over 20% in order to be profitable. For non-infectious diseases such as Sole Ulcer (SU) or White Line Disease (WLD), the return rate is higher. Incidence rates can be as low as 20% and effectiveness to reduce incidence at 20% in order to pay off investment.
A group from the University of Kentucky produced the model, where consultants can see the incidence rate of lameness type from the dairy, estimate the effectiveness of their prevention strategy (e.g. rubber flooring for reducing SU at a Risk Ratio of 0.45) and see a value in Dollars of estimated returns. This is an extremely useful and up to date model for estimating the value of advice on lameness interventions.
How was the model calculated?
The model was based on setting incomes at current prices (milk sales, calf sales and slaughter sales) and outgoings (feed, breeding, disposal and vet costs). Then the model was calculated at different incidence rates (set at 20, 40 and 60% for DD and 5, 15 and 25% for SU and WLD) and varying Risk Ratios of effectiveness of strategy. There is little published evidence on specific Risk Ratios for each prevention strategy, so the model was calculated in order for the reader to use their own value on incidence reduction from their chosen intervention.
For DD, the incidence rates needed to be quite high (40% or over) before a profit could be made at an effectiveness of 20% or above. For SU and WLD, profits can be made at a lower level of investment, generally, from >20% incidence and >20% effectiveness. Of course, this is variable depending on prevention intervention cost and parity of cow but these figures come from typical current interventions and dairy data incidence rates.