The aim of the intervention study 'outdoor veal calf' was to evaluate a novel concept for calf fattening which aimed at reducing antimicrobial use without compromising animal health. Management practices such as commingling of calves from multiple birth farms, crowding, and suboptimal barn climate are responsible for high antimicrobial use and mortality in the veal calf population. The risk of selecting bacteria resistant to antimicrobials and of economic losses is accordingly elevated. The 'outdoor veal calf' concept, implemented in nineteen intervention farms (IF), is based on three main measures: 1. purchased calves are transported directly from neighboring birth farms to the fattening facility instead of commingling calves in livestock dealer trucks; 2. each calf is vaccinated against pneumonia after arrival and completes a three-week quarantine in an individual hutch; and 3. the calves spend the rest of the fattening period in outdoor hutches in groups not exceeding 10 calves. The covered and bedded paddock and the group hutches provide shelter from cold weather and direct sunshine, constant access to fresh air is warranted. Nineteen conventional calf fattening operations of similar size served as controls (CF). Every farm was visited once a month for a one-year period, and data regarding animal health, treatments, and production parameters were collected. Treatment intensity was assessed by use of the defined daily dose method (TIDDD in days per animal year), and calf mortality and daily weight gain were recorded in both farm groups. Mean TIDDD was 5.3-fold lower in IF compared to CF (5.9 ± 6.5 vs. 31.5 ± 27.4 days per animal year; p < 0.001). Mortality was 2.1-fold lower in IF than in CF (3.1% ± 2.3 vs. 6.3 % ± 4.9; p = 0.020). Average daily gain did not differ between groups (1.29 ± 0.17 kg/day in IF vs. 1.35 ± 0.16 kg/day in CF; p = 0.244). A drastic reduction in antimicrobial use and mortality was achieved in the novel 'outdoor veal calf' system without compromising animal health. The principles of risk reduction used in designing the system can be used to improve management and animal health, decrease the need for antimicrobial treatments and thus selection pressure on bacteria in veal operations.

中文翻译：

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新概念“户外小牛犊”对瑞士抗菌药物的使用，死亡率和体重增加的影响。

干预研究“室外小牛犊”的目的是评估一种新颖的小牛育肥概念，旨在减少抗菌药物的使用而不损害动物健康。小牛种群中的高抗菌素使用率和死亡率是造成管理习惯的原因，例如将多个产地的牛犊混合在一起，拥挤和谷仓气候欠佳。因此，选择抗微生物细菌的风险和经济损失的风险因此增加。在19个干预农场（IF）中实施的“室外小牛犊”概念基于以下三个主要措施：1.将购买的小牛直接从相邻的生猪场运到育肥设施，而不是将小牛用牲畜交易卡车混合。2。每只小牛到达后都接种了肺炎疫苗，并在单独的储藏室中完成了为期三周的隔离；3.小牛在剩下的育肥期中，以不超过10头小牛的形式在室外储藏室中度过。带顶棚和有床的围场和集体储物箱为寒冷天气和阳光直射提供了庇护所，应保证不断获得新鲜空气。类似大小的十九个常规小牛育肥操作用作对照（CF）。每个农场在一年的时间内每月访问一次，并收集有关动物健康，处理和生产参数的数据。通过使用规定的日剂量方法（每动物年天数中的TIDDD）评估治疗强度，并记录两组农场的小牛死亡率和日增重。与CF相比，IF的平均TIDDD低5.3倍（5.9±6。每只动物年5天比31.5±27.4天；p <0.001）。IF的死亡率比CF低2.1倍（3.1％±2.3 vs. 6.3％±4.9； p = 0.020）。两组之间的平均日增重没有差异（IF组为1.29±0.17 kg /天，CF组为1.35±0.16 kg /天； p = 0.244）。在新颖的“户外小牛犊”系统中，抗菌药物的使用和死亡率得到了大幅降低，而没有影响动物的健康。设计系统时使用的降低风险原则可用于改善管理和动物健康，减少对抗菌治疗的需求，从而减少小牛肉操作中细菌的选择压力。每天35±0.16千克CF p = 0.244）。在新颖的“户外小牛犊”系统中，抗菌药物的使用和死亡率得到了大幅降低，而没有影响动物的健康。设计系统时使用的降低风险原则可用于改善管理和动物健康，减少对抗菌治疗的需求，从而减少小牛肉操作中细菌的选择压力。每天35±0.16千克CF p = 0.244）。在新颖的“户外小牛犊”系统中，抗菌药物的使用和死亡率得到了大幅降低，而没有影响动物的健康。设计系统时使用的降低风险原则可用于改善管理和动物健康，减少对抗菌治疗的需求，从而减少小牛肉操作中细菌的选择压力。