Department of Animal Medicine, Production and Health, University of Padova, Viale dell'Università 16, 35020 Legnaro, Padova, Italy.
Prev Vet Med. 2022 Oct;207:105715. doi: 10.1016/j.prevetmed.2022.105715. Epub 2022 Jul 12.
In recent years, the scientific community, institutions, and public opinion have shown a growing awareness towards the problem of antimicrobial resistance. Guidelines from the European Union aim at significantly reducing (even avoiding) the antimicrobial use for prophylactic and metaphylactic purposes in veterinary medicine and this represents an important issue for several intensive farming systems, such as the veal industry. This retrospective observational cohort study analyzed net carcass weight data at the slaughter of 618 veal calves belonging to 6 batches of animals fattened in an Italian commercial farm according to the number of individual antimicrobial treatments administered during the fattening cycle. Sixty-eight percent (419 animals) of the overall sample of calves received at least one individual antimicrobial treatment due to a disease event during the fattening, and 280 of these (45 % of the overall sample) had more than one treatment. On average, the net carcass weight of calves individually treated more than once was about 10 kg lower than that of untreated calves or treated only once. Moreover, the carcasses of calves that received more than one treatment were 16 times more at risk of being severely penalized in payment at the slaughterhouse due to a net weight below 110 kg than those of untreated calves. Serum analysis data of a subsample of 105 calves belonging to 3 out of the 6 batches collected within 5 days after their arrival to the veal farm identified 3 persistently infected animals by bovine viral diarrhea (BVD) virus and a prevalence of calves with serum immunoglobulin concentration below 7.5 g/L of 37 %. The presence of specific antibodies against infectious bovine rhinotracheitis (IBR) and bovine respiratory syncytial virus (BRSV) and a serum immunoglobulin level above 7.5 g/L at the onset of the fattening were the most important factors associated with a decreased risk of multiple individual antimicrobial treatments (and thus, disease development) or with a delay in disease onset during the fattening, thus leading to better performances at the slaughter. The outcomes of this study suggested that a relationship could exist between calf serostatus upon arrival to the veal farm and the possibility to avoid multiple individual antimicrobial treatments during fattening. Further research is needed to deeply study this association, as such knowledge would allow for planning effective preventing strategies to reduce the antimicrobial use in veal calves.
近年来，科学界、机构和公众对抗菌药物耐药性问题的认识不断提高。欧盟的指导方针旨在大幅减少（甚至避免）兽医领域中用于预防和辅助治疗目的的抗菌药物使用，这对许多集约化养殖系统（如小牛肉行业）来说是一个重要问题。本回顾性观察队列研究分析了在意大利一家商业农场育肥的 6 批动物中屠宰的 618 头小牛肉的净胴体重数据，这些动物根据育肥期间接受的个体抗菌治疗次数进行分组。在整个小牛样本中，68%（419 头）的小牛因育肥期间发生疾病而至少接受了一次个体抗菌治疗，其中 280 头（总体样本的 45%）接受了不止一次治疗。平均而言，多次接受个体治疗的小牛的净胴体重比未接受治疗或仅接受一次治疗的小牛低约 10 公斤。此外，接受多次治疗的小牛的胴体因净重在 110 公斤以下而在屠宰场受到严重罚款的风险比未接受治疗的小牛高 16 倍。在从 6 批中的 3 批中收集的 105 头小牛的血清分析数据中，通过牛病毒性腹泻（BVD）病毒鉴定出 3 头持续感染动物，并且血清免疫球蛋白浓度低于 7.5 g/L 的小牛的患病率为 37%。在育肥开始时，存在针对传染性牛鼻气管炎（IBR）和牛呼吸道合胞体病毒（BRSV）的特异性抗体以及血清免疫球蛋白水平高于 7.5 g/L，是与减少多次个体抗菌治疗（因此减少疾病发展）或在育肥期间延迟疾病发作的风险降低相关的最重要因素，从而提高屠宰性能。本研究结果表明，小牛到达小牛肉农场时的血清阳性状态与在育肥期间避免多次个体抗菌治疗的可能性之间可能存在关联。需要进一步研究以深入研究这种关联，因为这种知识将允许制定有效的预防策略来减少小牛肉牛的抗菌药物使用。
