Fig. 1

Estimated on-farm intramammary antimicrobial usage for in-lactation and dry cow therapy in Ireland during 2013 to 2020, expressed as defined course dose (DCDvet). These data are based on sales data collated by Kynetec and 5 other individual suppliers, which is assumed to represent 99% of sales data from 2013 onwards. The black bars represent the DCDvet per cow per year for dry cow therapy using the original formula to estimate the number of cows at risk of dry cow therapy. The white bars represent DCDvet per cow per year for dry cow therapy using a new simplified version of the formula to estimate the number of cows at risk of dry cow therapy