Mastitis epidemiology and costs in 125 Italian dairy herds

In this paper we report data on mastitis epidemiology and costs collected in a field study on 125 Italian dairy herds. Herds were enrolled on voluntary bases in several Italian regions (Calabria, Lombardia, Puglia, Sardegna, Sicilia, Trentino, Basilicata, Emilia e Lazio). Data were collected through a questionnaire specifically developed to collect data on herd management, therapeutical protocols and mastitis occurrence routinely applied in our advisory service to farms (Gesan questionnaire). Quarter milk samples were collected from 15-36 cows based on an epidemiological sampling scheme. Mastitis costs were estimated by partial budget analysis applying the spreadsheet developed by Fetrow and modified to fit to Italian dairy herd characteristics. To define herd objectives, the following rules were applied: 1. Reduction of BTSCC below EU legal threshold (400.000 cells/ml) if herd average showed valued over the threshold 2. Reduction of BTSCC of 30% if the values were below legal threshold but higher than 250.000 cells/ml 3. Reduction of BTSCC of 20% in all the other cases 4. Reduction of clinical mastitis monthly frequency to 2% if actual incidence was in the range 2-4% 5. Reduction of clinical mastitis monthly frequency of 50% if actual incidence was higher than 4% 6. Reduction of 50% of culling due to mastitis. Microbiological data showed as S.aureus was recovered from 59% of the herds, while Str.agalactiae was isolated from 16%, environmental Strep from 57% and coliforms from 13% of the herds. Data show that clinical mastitis frequency is still very high in Italian herds with 30% of herds having a monthly frequency of clinical mastitis in the range 2-4% and 33% with a frequency higher than 4%. Risk factors as cow age, season and housing showed to have an influence on clinical mastitis occurrence, but their importance was strongly influenced by herd hygiene management. The data showed as the average cost of clinical mastitis was 177€/case with mean costs of 96€/case for mild cases and 263€/case for severe ones. The overall cost for intramammary infections estimated was 318€/cow. Costs showed to be relatively lower in small herds (<50 cows) with estimated cost of 300€/cow and higher in large herds (>200 cows) with estimated costs of 400€/cow.