Antimicrobial use on Canadian dairy farms

Abstract

Antimicrobial use (AMU) data are critical for formulating policies for containing antimicrobial resistance. The present study determined AMU on Canadian dairy farms and characterized variation in AMU based on herd-level factors such as milk production, somatic cell count, herd size, geographic region and housing type. Drug use data were collected on 89 dairy herds in 4 regions of Canada, Alberta, Ontario, Québec, and the Maritime provinces (Prince Edward Island, New Brunswick, and Nova Scotia) for an average of 540 d per herd. Dairy producers and farm personnel were asked to deposit empty drug containers into specially provided receptacles. Antimicrobial use was measured as antimicrobial drug use rate (ADUR), with the unit being number of animal defined-daily doses (ADD)/1,000 cow-days. Antimicrobial drug use rates were determined at farm, region, and national level. Combined ADUR of all antimicrobial classes was 14.35 ADD/1,000 cow-days nationally. National level ADUR of the 6 most commonly used antimicrobial drug classes, cephalosporins, penicillins, penicillin combinations, tetracyclines, trimethoprim-sulfonamide combinations, and lincosamides were 3.05, 2.56, 2.20, 1.83, 0.87, and 0.84 ADD/1,000 cow-days, respectively. Dairy herds in Ontario were higher users of third-generation cephalosporins (ceftiofur) than in Québec. Alberta dairy herds were higher users of tetracyclines in comparison to Maritimes. Antimicrobial drug use rate was higher via systemic route as compared with intramammary and other routes of administration (topical, oral, and intrauterine). The ADUR of antimicrobials used intramammarily was higher for clinical mastitis treatment than dry cow therapy. For dry cow therapy, penicillin ADUR was greater than ADUR of first-generation cephalosporins. For clinical mastitis treatment, ADUR of intramammary penicillin combinations was greater than ADUR of cephapirin. Herd-level milk production was positively associated with overall ADUR, ADUR of systemically administered ceftiofur, cephapirin administered for dry cow therapy, and pirlimycin administered for clinical mastitis treatment. Herd size and ADUR of systemically administered ceftiofur were also positively associated. In conclusion, β-lactams were most commonly used on Canadian dairy farms. Among antimicrobials of very high importance in human medicine, the use of fluoroquinolones was rare, whereas third-generation cephalosporins and penicillin combinations containing colistin were used very frequently on Canadian dairy farms.

Survey on Antimicrobial Residues in Raw Milk and Antimicrobial Use in Dairy Farms in the Emilia-Romagna Region, Italy

“…González et al (2010) reported that penicillins, sulphonamides, aminoglycosides and tetracyclines were the most frequently used active substances in Switzerland, whereas use of third and fourth generation cephalosporins, fluoroquinolones and macrolides was low. Cephalosporins, penicillin combinations, and tetracyclines were the most commonly used antimicrobial drug classes on Canadian dairy farms (Saini et al, 2012) similar to findings on Dutch dairy farms (Mevius et al, 2009). Generally speaking, β lactams were used on all dairy farms and constituted the highest proportion of antimicrobials with cephalosporins used at a higher rate than penicillins.…”

“…may also differ. The use of antimicrobials in dairy farms varies in different countries (Hill et al, 2009;González et al, 2010;Saini et al, 2012), and this may depend on the different Regulations in force. Our findings can be roughly compared to the study by Hill et al (2009) in the USA which reported that the most common primary treatments for both lameness and respiratory disease in lactating cows were penicillins, cephalosporins and tetracyclines, whereas cephalosporins were the most common primary treatment for mastitis, closely followed by penicillins and then macrolides.…”

Climate conditions associated with the occurrence of antimicrobial and macrocyclic lactone residues in bulk tank milk

“…For instance, Washburn et al (2002) reported that cows in confinement had 1.8 times more clinical mastitis and eight times the rate of culling for mastitis than did cows on pasture. Thus, it should be considered that clinical mastitis is a major reason for antimicrobial drug usage in dairy cows and is even higher than dry cow therapy, treatment of metritis, and foot and respiratory diseases (Pol and Ruegg, 2007;Saini et al, 2012). Figure 1.…”

<b>Etiological and molecular profile of pathogens causing clinical mastitis, and antimicrobial use in dairy herds</b>

“…Furthermore, the availability of data on antimicrobial use can aid in interpreting patterns and trends of antimicrobial susceptibility among bacteria causing CM, and serve as a basis of risk assessment and evaluation of interventions for controlling of AMR. Data on antimicrobial use for treatment of bovine CM are, therefore, becoming increasingly important for development of policies to contain AMR (SAINI et al, 2012b).…”

“…However, the quantification of antimicrobial formulations used for treatment of CM was not described in dairy herds in Brazil. Furthermore, there are few studies that have evaluated the association between the frequency of antimicrobials used for treatment of CM and herd-level descriptors such as SCC, TBC, housing system, herd size and milk production (HILL, A. E. et al, 2009;SAINI et al, 2012b;STEVENS et al, 2016). Studies characterizing the antimicrobial use in dairy herds can benefit the dairy industry as they can be used as a basis for implementation of programs for the prudent use of antimicrobials, and consequently, for prevention of bacterial AMR.…”