The evolutionary operation framework as a tool for herd-specific control of mastitis in dairy cows

Mastitis is the most prevalent and costly production disease in the dairy industry, but udder health advice that helps one herd might not be beneficial for another because of "local truths". It is therefore important to identify what mastitis control options may work in a specific herd in the conditions specific to the herd. We evaluated whether the Evolutionary Operation (EVOP) methodology could be used as a management tool to identify mastitis control options to improve udder health in dairy herds. Within an EVOP framework we conducted sequences of experiments, on each of two dairy farms in Sweden. The experiments covered interventions within 1) hygiene in cubicles, 2) milking routines, and 3) dry-off procedures. Automatically recorded somatic cell counts (SCCs) in milk were used as the response variable. The impact of the interventions on SCC was evaluated with multivariate dynamic linear models. Farmer and staff satisfaction was assessed through interviews. The EVOP methodology was successfully applied, and the farmers appreciated it. We observed herd-specific variation in the effect of the interventions, indicating that EVOP would be a feasible approach to tailor mastitis control options to individual herds. Our results indicate that the EVOP methodology could be a tool to identify and evaluate health management strategies on dairy farms.