Main antimicrobials used and principal reasons for their use in Irish pig farms

Antimicrobial resistance (AMR) is a major human and animal health problem that is linked with antimicrobial usage. Given current knowledge of the problems caused by AMR in humans and animals, it is important to explore the reasons for differing levels of antimicrobial use in Irish pig production and assess its impact on animal health and performance.

A questionnaire including 90 questions on different aspects of pig production such as health, antimicrobial use, welfare, management practices and biosecurity was designed by the research team and reviewed by policy makers and private pig veterinary practitioners. Between November and December 2014, 80 questionnaires were distributed to pig farmers at various events with provisions for return by post. Results were entered in Excel and descriptive statistics of the data produced.

A total of 28 pig farmers (9% of commercial Irish herds) returned questionnaires. The average number of sows on their farms was 737 (range 83 to 2900). The number of litters per sow per year was between 2.1 and 2.4 and the number of pigs born per sow per year ranged from 26 to 34.5. The main reasons cited for the use of antimicrobials in piglets were diarrhoea (52%), lameness (16%) and poor growth (16%). In first stage weaned pigs, meningitis and poor growth were reported by 25% of farmers and diarrhoea and respiratory problems by 17%. In second stage weaned and finishing pigs the main problems reported were respiratory issues (32 and 26%), poor growth (20 and 13%) and lameness (16 and 17% respectively). Lameness (40%) and MMA (12%) were the principal reasons for antimicrobial use in sows. In-feed antimicrobials were mostly used in first (42%) and second (32%) stage weaned pigs. Piglets, finishing pigs and sows were mainly treated by injected antibiotics. A wide variety of antimicrobials were used in piglets with more than 10 products cited. In growing and finishing pigs use of between 4 and 6 different antimicrobials was recorded, with penicillins and tetracyclines being the most common.

The 28 farms were representative of the Irish pig industry in terms of size, performance figures and geographical location. The main reasons given for the use of antimicrobials were poor growth, respiratory disease and lameness. In-feed medication was used mainly in first and second stage weaned pigs and penicillins and tetracylines were the most commonly employed antimicrobials. This preliminary study will be extended to a higher percentage of farms during 2016.

Disclosure of Interest: None Declared.