The informative value of an overview on antibiotic consumption, treatment efficacy and cost of clinical mastitis at farm level.

This paper addresses whether it is worthwhile investing time in a more comprehensive documentation and analysis of farm specific data for mastitis treatment. Whilst most farmers keep some records, many refrain from investing more effort in making them more detailed. Therefore, information on farm-specific antibiotic consumption, effectiveness of treatments and the costs of mastitis are lacking; as well as the ability to identify and realise possibilities for improvement. An observational study was conducted on 30 dairy farms, to obtain an overview of farming practice, recording detailed data (using herd management software) on: milk records, diagnostics, preventive and therapeutic treatments and cost of mastitis, on an individual cow level. Out of a total of 30,633 cows, 67% received medication for the treatment or prevention of mastitis over a year. Antibiotics were chosen for 96% of udder treatments; including those for dry cows. Over 32% of the antibiotics used during lactation belonged to the 'highest priority critically important antimicrobial' category. Success of therapeutic treatment (assessed by individual somatic cell count (SCC)) ranged from 18% to 59% and total costs of mastitis per cow and year from € 158 to € 483. The high variations in antibiotic consumption, treatment outcomes and cost of mastitis between farms, showed that average or incomplete figures risk giving the wrong impression of a farm. It is thus worthwhile to invest in documentation and analysis of data, so that it is clear where action is required and which investments can be expected to be financially feasible. Benefits emerge from knowledge of antibiotic consumption allowing monitoring and reduction in antibiotic use (as demanded by consumers and legislation), improvements in animal health and welfare thanks to regular checks of how effective a treatment is, and economic benefits due to knowledge of the costs caused by mastitis.