A partial budget analysis to estimate the economics of a mastitis vaccination program

Abstract

STARTVACR is a vaccine aimed to reduce mastitis caused by Staphylococcus aureus, Escherichia coli and coagulase-negative staphylococci. The objective of this economical analysis was to estimate the net profit of vaccination using data from a clinical trial where 343 cows from six Spanishherds were randomized either to a control (C) or a vaccination group (V). Outcomes were evaluated up to 130 days after parturition. The economic value of the reduction in the days that milk was discarded was estimated by multiplying the difference between both study groups (C = 1.6 days; V = 0.9 days; Diff. = 0.7 days) by daily milk production (30 kg/cow) and milk price (0.30 €/kg). A cost of € 46 per casewas used in the calculation of the reduction in treatment costs due to less clinical mastitis (C = 15%; C = 4%; Diff. = 11%). Although there was a reduction in SCC weighted by the cow’s milk production (C = 559,000 cells/ml; V = 431,000 cells/ml), no additional revenues were estimated because SCC did not drop below the 250,000 cutoff point used by most milk processors in Spain to pay premiums. In the estimation of the reduction in culling costs (C = 9%; V = 5%; Diff. = 4%), the cost of a cull cow was estimated as the average value of a cow in the herd minus the average cull cow’s salvage value (€ 1,250 - € 500 = € 750). The vaccination program costs were estimated in € 17 per cow and lactation. The overall net profit of the vaccination intervention was €25 per cow in the first 130 after parturition (direct effects). In addition, the observed reduction in subclinical mastitis incidence (C = 46%; V = 18%) is expected to result on a reduction of cow-to-cow transmission of mastitis pathogens (indirect effects).