Qualitative and quantitative monitoring of antibiotics on dairy cattle farms in relation to animal welfare indicators

Antimicrobial resistance is a growing concern for the scientific community and the public, so many countries have stepped up monitoring to tackle it and promote correct antimicrobial use. The welfare assessment protocol for dairy cows used by the Italian National Reference Centre for Animal Welfare (CReNBA) recommends lowering the use of antibiotics, so this study assessed the effects of the introduction of the welfare score on antimicrobial use and animal welfare between 2015 and 2018. For this study, 23 dairy farms in northern Italy (Piedmont) were enrolled. Data on animal categories (calf, heifer and cow) and antimicrobial use were extrapolated from mandatory farm registers. The antimicrobial animal-defined daily dose (ADDD) and the ADDD per year (ADDD/year) were calculated. Each farm was evaluated with the CReNBA welfare assessment protocol for dairy cows. An increase was recorded for 2018 regarding the number of reared animals (especially adult cows) and in the welfare (2015: 71.44% ± 7.84% vs. 2018: 76.18% ± 6.40%; p < 0.05) and biosecurity score (2015: 44.42 ± 11.87 vs 2018: 60.49 ± 11.13; p ≤ 0.01). The mean ADDD/y was lower for 2018 (3.04 ± 1.3 vs. 3.61 ± 1.5; p = 0.01), despite the extensive use of beta-lactams and cephalosporins. Most farms with high welfare scores showed a lower ADDD/y in both years. The correlation between higher levels of animal welfare and lower antimicrobial consumption suggests that drug use can be reduced improving animal well-being on the farm. Further reductions may be achieved by strengthening synergism between public health agencies and farm veterinarians.