Animal Health: Mastitis 1

摘要

The objective of the research was to evaluate the cost of S. uberis mastitisand the profitability of vaccination protocols. Literature data were reviewedto determine the average incidence and effects of clinical and subclinicalS. uberis mastitis and the impact of vaccination on the incidenceand effects. A stochastic dairy herd simulation program (www.dairyfarm.es) was used to simulated different scenarios. The modeled farm was a300 adult cows producing 11.500L/cow/year with an SCC of 200 × 103cells/mL. Milk price was 0.35€/L with 0.02€/L penalty if somatic cellcount were above 300 × 103/mL. The behavior of S. uberis mastitis isvariable and may become chronic in some cases. However, average valuesof literature were used. Control scenario was tested with an average incidenceof 12.5%, where 4% were clinical and 8.4% subclinical mastitis. Inall cases, the incidence in primiparous cows was 25% of that of multiparouscows, culling risk was 36% and the risk of recurrence increased 35%after the first case. Clinical cases lasted 13 d where milk production wasreduced 5% daily, conception rate was reduced by 26% during 42 d afterthe infection, and somatic cell count was multiplied by 4. Treatment costwas 30€/case including antibiotics and labor, with a recovery rate of 90%,and milk had to be withdrawn for 10 d. Subclinical cases lasted 45 d with a7% daily reduction in milk yield and somatic cell count was multiplied by4, but with no effects on reproduction. The vaccine (UBAC, LaboratoriosHipra SA, Spain) was applied 3x/year at 4,7€/dose including vaccine costand labor, and reduced the incidence of clinical and subclinical diseasesby 50%. In cows vaccinated but infected, the effects were reduced by50%. All simulations were conducted for 5 years and were repeated 66times. The cost of a case of mastitis by S. uberis was on average 88.80€.With an average incidence of 12.5%, vaccination increased the grossmargin by 47€/cow/yr. The sensitivity analysis indicates that the breakevenpoint for the application of the vaccine is for an incidence of 3.4%.