Economic impact and profile of etiologic agents of bovine mastitis

Abstract

The general objectives of this proposal are to evaluate: a) etiologic profile and antimicrobial susceptibility of pathogens causing clinical mastitis and to describe the qualitative and quantitative aspects relating to the use of antimicrobials; b) efficiency of on farm culture program, specially on the use of antimicrobials and economic aspects related to expenses incurred for clinical mastitis therapy; production losses and milk composition changes associated with somatic cell count at herd level. The specific objectives of this proposal will be achieved by performing of two subprojects (1 e 2) and the following objectives: Subproject 1: Impact of subclinical mastitis on production cost and milk quality of dairy herds. The general objective of this subproject is to evaluate the effects of subclinical intramammary infections caused by primary pathogens on somatic cell count and milk yield and composition of dairy cows at mammary quarter level; In addition, the Subproject 1 aims to evaluate production losses and changes in milk composition at herd level by SCC; and to determine the economic impact of subclinical mastitis caused by major pathogens in dairy herds. Three experiments will be performed to achieve the objectives of the Subproject 1: Experiment 1 - Effect of subclinical mastitis caused by primary pathogens on production and milk composition of dairy cows at mammary quarter level; Experiment 2 - Production losses and milk composition changes caused by subclinical mastitis at herd level; Experiment 3 - economic impact of subclinical mastitis caused by primary pathogens on the milk production cost of dairy herd. Subproject 2: Etiological profile of clinical mastitis and antimicrobial use in dairy herds. General objective: to determine the etiologic profile and antimicrobial susceptibility of clinical mastitis pathogens, and to describe the qualitative and quantitative aspects associated with antimicrobial drug usage for treatment of mastitis in dairy herds. Additionally, the study aims to evaluate the effectiveness of the on farm microbiological culture (OFC) on use of antimicrobials and economic evaluation of clinical mastitis therapy protocols. Three experiments will be performed to achieve the objectives of Subproject 2: Experiment 1 - Determination of etiologic profile of clinical mastitis in dairy herds; Experiment 2 - Quantification of antimicrobial drug usage for treatment of mastitis; and Experiment 3 - Economic approach and evaluation of risk factors related to a program of on farm microbiological culture. Overall, this proposal is focused on the etiologic and epidemiologic evaluation of intramammary infections, aiming to promote alternatives to mastitis control, reduction of somatic cell count and reduction of antimicrobials used for clinical mastitis therapy. (AU)