Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
Veterinary Practice Venhei, Geelsebaan 95-97, 2460 Kasterlee, Belgium.
J Dairy Sci. 2019 Jan;102(1):607-618. doi: 10.3168/jds.2018-15211. Epub 2018 Nov 8.
The intensive use of antimicrobials in the veal industry is heavily criticized, but drivers for antimicrobial usage (AMU) are still poorly understood. The industry fears that a drastic reduction in AMU would increase mortality, creating an unacceptable welfare issue. The objectives of the present study were to identify risk factors for AMU and to explore the relationship between AMU and mortality. A retrospective cohort study was performed on the antimicrobial registration data from the largest Belgian veterinary veal practice. The data set contained 295 production cycles from 78 farms, representing 146,014 calves and 8 veal companies (also called integrations). The average AMU was 32.3 defined daily dose animal per year (standard deviation: 11.04), of which 76.2% was administered orally and 23.8% parentally. The AMU remained stable between 2014 and 2016 with only a slight, but significant increase in total AMU between 2015 (31.0 defined daily dose animal per year, standard deviation: 10.5) and 2016 (35.1, 10.8). Use of almost all antimicrobial classes decreased over 2014 to 2016; however, use of long-acting macrolides, doxycycline, and aminosides increased significantly. Analysis identified breed (higher use in beef calves compared with dairy and crossbreeds), month of arrival (lower use when arrived in April or May compared with winter months), and veal company as risk factors. The veal company not only significantly affected total AMU, but also affected the majority of the antimicrobial classes. Additionally, breed differences were present for oxytetracycline, colistin, and classic macrolides, and a month effect was present for doxycycline only. These data illustrate that this veterinary practice realized a reduction of 46% in total AMU and of 96% in critically important antibiotics (fluoroquinolones, cephalosporins of the third and fourth generation) compared with the Belgian benchmark from 2007 to 2009. Replacement of critically important drugs by an increased use of long-acting macrolides is worrisome. Mortality risk was very low compared with benchmarks referenced internationally and did not increase with decreasing AMU. Use of trimethoprim-sulfonamides was a risk factor, whereas use of oxytetracycline was a protective factor for mortality. The absence of a relationship with mortality at the current levels of AMU suggests that a further rational reduction is possible. Attention should be paid to consider different AMU benchmarks for different breeds and to include the veal company as a target for antibiotic awareness campaigns.
在小牛肉行业大量使用抗生素受到了强烈批评，但人们对使用抗生素的驱动因素（AMU）仍知之甚少。该行业担心，如果大幅度减少 AMU，死亡率将会上升，从而造成不可接受的福利问题。本研究的目的是确定 AMU 的风险因素，并探讨 AMU 与死亡率之间的关系。对来自比利时最大的兽医小牛肉实践的抗菌剂登记数据进行了回顾性队列研究。该数据集包含 78 个农场的 295 个生产周期，代表了 146014 头小牛和 8 家小牛肉公司（也称为一体化公司）。平均 AMU 为每年 32.3 个定义的每日剂量动物（标准差：11.04），其中 76.2%为口服给药，23.8%为肠胃外给药。2014 年至 2016 年间，AMU 保持稳定，仅在 2015 年（每年 31.0 个定义的每日剂量动物，标准差：10.5）和 2016 年（35.1，10.8）之间总 AMU 略有但显著增加。2014 年至 2016 年间，几乎所有抗菌药物类别的使用都有所减少；然而，长效大环内酯类、强力霉素和氨基糖苷类的使用显著增加。分析确定了品种（与奶牛和杂交品种相比，肉牛小牛的使用量更高）、到达月份（与冬季月份相比，4 月或 5 月到达时的使用量较低）和小牛肉公司为风险因素。小牛肉公司不仅显著影响总 AMU，还影响大多数抗菌药物类别。此外，在土霉素、黏菌素和经典大环内酯类药物方面存在品种差异，仅在强力霉素方面存在月份差异。这些数据表明，与 2007 年至 2009 年比利时的基准相比，该兽医实践的总 AMU 减少了 46%，而对关键重要抗生素（氟喹诺酮类、第三代和第四代头孢菌素）的使用减少了 96%。用长效大环内酯类药物替代关键重要药物令人担忧。与国际参考基准相比，死亡率风险非常低，且随着 AMU 的减少而没有增加。使用甲氧苄啶-磺胺类药物是死亡的危险因素，而使用土霉素是死亡的保护因素。在当前 AMU 水平下与死亡率之间没有关系表明，进一步的合理减少是可能的。应注意为不同品种考虑不同的 AMU 基准，并将小牛肉公司作为抗生素意识运动的目标。
