Comparison of treatment records and inventory of empty drug containers to quantify antimicrobial usage in dairy herds

Abstract

Assessment of antimicrobial use (AMU) is vital for interpreting the origin of changes in antimicrobial resistance (AMR). The objectives of the present study were to estimate the association between AMU determined using on-farm treatment records (TR) and inventory of empty drug containers (INV). Herds were selected to represent Canadian dairy farms. Producers were asked to record animal health events and treatments on a standard General Health Event form. For inventory data, 40-L receptacles were placed at various locations considered convenient to deposit all empty drug containers. Antimicrobial defined-daily dosages (ADD) were calculated for 51 Canadian herds using the 2 methods. Estimation of AMU was 31,840 ADD using the INV and 14,487 ADD using the TR, indicating that for every TR entry, 2.20 times more treatments were observed using the INV. Mastitis, reproductive conditions, and dry cow therapy were the most frequent reasons for antimicrobial therapy when assessing TR. For all antimicrobials evaluated, mean ADD was higher using the INV versus TR. Regardless, a strong positive correlation (0.80) was observed between the 2 methods, indicating that herds with increased number of ADD recorded using the INV also had increased number of ADD recorded using TR. Furthermore, a positive association was observed for the 6 most commonly used antimicrobials. In comparison to methods used in surveillance programs on AMU in livestock that assume a constant use in all herds (i.e., sales data), INV provided a herd-level specific quantity of AMU positively correlated with AMU recorded at the animal level in general. The INV was easy to implement and provided a measure of total AMU in the herd. Availability of such information would be valuable for interpreting changes in AMR at the herd level and enabling evaluation of interventions for decreasing AMR.

Antimicrobial Usage in Animal Production: A Review of the Literature with a Focus on Low- and Middle-Income Countries

“…Thirteen studies reported dose-based data from dairy farms. All studies came from Europe, except one each from Argentina [ 93 ], the USA [ 91 ], and Canada [ 85 ]. One study reported AMU in heifers before calving [ 69 ], and another one reported AMU to treat mastitis [ 91 ] exclusively.…”

Prevalence and Genetic Basis of Antimicrobial Resistance in Non-aureus Staphylococci Isolated from Canadian Dairy Herds

“…Non- aureus staphylococci (NAS) have emerged as the most frequently isolated group of pathogens in intramammary infections (IMI) in dairy cows, with an estimated udder quarter-level prevalence of 26 cases per 100 quarters (Condas et al, 2017 ). Worldwide, mastitis remains one of the most frequent reasons for antimicrobial therapy in dairy herds (Mitchell et al, 1998 ; Brunton et al, 2012 ; Nobrega et al, 2017 ). Therefore, NAS are in relatively frequent contact with antimicrobials.…”

MicroRNA‐145 regulates immune cytokines via targeting FSCN1 in Staphylococcus aureus‐induced mastitis in dairy cows

“…Cow mastitis is a detrimental factor in milk quality and food safety (Cha et al, ). The current approach for the drug treatment of cow mastitis is prone to result in residual drugs remaining and drug resistance problems (Nobrega et al, ). In‐depth study of the pathogenic and immune mechanisms of pathogens can provide a theoretical basis for the development of new methods for the treatment and prevention of mastitis.…”