Antibiotic Usage Pattern in Broiler Chicken Flocks in Germany

Abstract

In this work, antimicrobial usage data from 2,546 commercial broiler chicken flocks originating from 37 farms are presented. Antimicrobial usage data at the flock level were based on mandatory documentation of antibiotic treatments in livestock in Germany, collected retrospectively for the time period of 2013–2018. The data encompasses all antimicrobial treatments during the fattening period of each flock, starting with the placement of day-old chicks at the barn. The aim of this analysis was to investigate antibiotic usage patterns in broiler chicken flocks in Germany, temporal trends in treatment frequency, the proportions of different antimicrobial classes and the weights of the broiler chickens at the time of treatment. The median treatment frequency over all flocks was six, and veterinary medicinal products belonging to nine different antimicrobial classes were used. Overall, the most frequently used classes were aminoglycosides (25.6%) and lincosamides (25.6%), followed by polypeptides (21.4%) and beta-lactams (16.2%). Over the 6 years evaluated, a considerable increase in the relative usage of lincosamides and aminoglycosides was observed. Compared to the first year of data collection, the percentage of treatments with fluoroquinolones, macrolides and polypeptides decreased in consecutive years. The median age of the broiler chickens at the time of treatment was 5 days, which corresponded to a median body weight at the time of treatment of 111 g, with substantial differences among various antimicrobial classes. We showed that in Germany, the median weight of broiler chickens at the time of treatment was substantially lower than the standard weight of broilers of 1,000 g proposed by the European Surveillance of Veterinary Antimicrobial Consumption. The median weight at treatment is very much influenced by the frequency of age-specific diseases. As different antimicrobial classes are used to combat these diseases, variations in the weight at treatment may have a considerable impact on the estimated treatment indicators. Additionally, a decrease in the relative usage of the highest-priority critically important antimicrobials, such as fluoroquinolones, macrolides and polypeptides, was shown, which might be the consequence of increasing awareness of the antibiotic resistance situation as well as of antibiotic monitoring and benchmarking systems currently running in Germany.

Use of Antimicrobials by Class in Pigs in Germany—A Longitudinal Description Considering Different International Categorisation Systems

“…Remarkably, colistin is only listed as highly, and not critically, important for animals in general [ 29 ], and many countries around the world use only small amounts of colistin to treat animals or have prohibited its use. This is in contrast with Germany, where it is regularly administered in veterinary medicine and where various authors have described a lack of alternatives for certain infectious diseases in animals [ 14 , 64 , 73 ]. Until recently, only veterinarians used colistin due to its toxicity in humans, making it a more appropriate choice for usage in veterinary medicine than cephalosporins and fluoroquinolones.…”

“…In 2013, the project continued as a longitudinal approach. For this, data collection occurred semi-annually via veterinarians or farmers, using an open cohort with ongoing recruitment, to balance out possible withdrawals [ 73 , 90 , 91 ].…”

Real-World Data on Antibiotic Group Treatment in European Livestock: Drivers, Conditions, and Alternatives

“…More than half of the poultry practitioners (n = 133/250, 53.2%) indicated very low to low metaphylaxis use, which is in sharp contrast to current market practices: Firstly, poultry is almost exclusively held in larger flocks and any disease diagnosed in poultry flocks requires treatment of the whole group irrespective of the morbidity rate and therefore inevitably treating a proportion of animals which are not (yet) showing clinical signs, reflecting the legal definition of metaphylaxis [ 6 , 8 , 10 ]. Secondly, VMPs for poultry are almost exclusively available as oral formulations and exclude therefore individual treatment [ 3 , 4 ].…”

“…Though all major farmed animals are gregarious, weaning represents a major stressor and subsequent (intra- or inter-farm) transport followed by regrouping adds to this, especially for calves. Some studies demonstrated that metaphylaxis in commercially reared cattle and pig holdings was most often implemented after weaning, transportation, and co-mingling, as these periods of stress are often followed by disease [ 6 , 7 , 8 ]. The antibiotic sales data mirror these findings as they represent a surrogate measure for animal group medications.…”

Comparison of Consumption Data and Phenotypical Antimicrobial Resistance in E. coli Isolates of Human Urinary Samples and of Weaning and Fattening Pigs from Surveillance and Monitoring Systems in Germany

“…Moreover, issues on the comparability of exposure of animal populations have been raised using the concept of defined daily doses in the veterinary field. On account of the massive growth of young meat producing animals such as broiler chicks, a variation in time of treatment may lead to substantial over or underestimation of the number of animals actually treated [ 55 ]. It has therefore been recommended to also collect data on the number of animals treated and the dosage [ 20 ].…”