Arcangioli M-A, Lurier T, Hauray K, Tardy F
UMR Mycoplasmoses animales, VetAgro Sup, Université de Lyon, 69280 Marcy-l'Etoile, France; UMR Mycoplasmoses animales, Anses, Université de Lyon, 69007 Lyon, France.
Université Clermont Auvergne, INRAE, VetAgro Sup, UMR EPIA, F-63122 Saint-Genès-Champanelle, France; Université de Lyon, INRAE, VetAgro Sup, UMR EPIA, F-69280 Marcy l'Etoile, France; Université de Lyon, INRAE, VetAgro Sup, USC 1233 UR RS2GP, 69280 Marcy-l'Etoile, France.
Animal. 2021 Dec;15(12):100397. doi: 10.1016/j.animal.2021.100397. Epub 2021 Nov 26.
Bovine respiratory disease is the leading user of antibiotics (AB) in calf production. Mycoplasma (M.) bovis could lead to greater use of AB as it is a persistent and AB resistant causative agent for respiratory diseases. Two cross-sectional studies were set up to assess the effects of lot size and feeding system on M. bovis infection and the effects of M. bovis seroconversion, lot size and feeding system on AB use in calves' feedlots. Twenty-six lots in 22 fattening farms were monitored for 41-81 days, from all-in entry of calves until three consecutive weeks without using any collective antibiotics. M. bovis spread was estimated by measuring seroconversion at entry and at the end of study period in 10-15 calves randomly sampled in each lot. All AB treatments used in the meanwhile were recorded. The lots were selected according to feeding system, i.e. individual bucket (n = 7) vs. automated milk feeder (AMF, n = 19), and lot size (30-519 calves), less than 50 calves (n = 9) vs. more than 50 calves (n = 17). Statistical analysis was performed using multivariable generalised linear models with fattening farms as random effect. M. bovis spread increased with lot size (odds ratio (OR) 2.9[1.4; 5.8] per two-fold increase in lot size). This proportion of seroconverted calves was lower in bucket-fed lots compared to lots fed with the AMF using a shared nipple (OR = 0.03[0.003; 0.41]). The main risk factor for AB use was the lot size, with an increase of 1.5[0.94; 1.98] treatments per two-fold increase in lot size. For same size lots, the use of bucket can decrease AB consumption by up to 1.03[-2.18; 0.14] treatments per calf compared to AMF. Analysis of the association between seroconversion to M. bovis and AB use was inconclusive. We found that bucket feeding in small-size lots, i.e. up to a maximum of 50 calves in the same space, limits seroconversion to M. bovis and enables lower use of AB in veal calf production.
牛呼吸道疾病是犊牛生产中抗生素使用的主要原因。牛支原体可能导致更多抗生素的使用，因为它是一种导致呼吸道疾病的持续性且对抗生素耐药的病原体。开展了两项横断面研究，以评估圈舍规模和饲养系统对牛支原体感染的影响，以及牛支原体血清转化、圈舍规模和饲养系统对犊牛饲养场抗生素使用的影响。对22个育肥场的26个圈舍进行了41至81天的监测，从犊牛全进直至连续三周不使用任何集体抗生素。通过测量每个圈舍随机抽取的10至15头犊牛入舍时和研究期末的血清转化情况来估计牛支原体的传播。同时记录在此期间使用的所有抗生素治疗情况。根据饲养系统选择圈舍，即个体桶饲（n = 7）与自动喂奶器（AMF，n = 19），以及圈舍规模（30至519头犊牛），小于50头犊牛（n = 9）与大于50头犊牛（n = 17）。使用以育肥场为随机效应的多变量广义线性模型进行统计分析。牛支原体的传播随圈舍规模增加（圈舍规模每增加一倍，优势比（OR）为2.9[1.4；5.8]）。与使用共享奶嘴的AMF饲养的圈舍相比，桶饲圈舍中血清转化犊牛的比例较低（OR = 0.03[0.003；0.41]）。抗生素使用的主要风险因素是圈舍规模，圈舍规模每增加一倍，治疗增加1.5[0.94；1.98]次。对于相同规模的圈舍，与AMF相比，使用桶饲每头犊牛可使抗生素消耗量减少多达1.03[-2.18；0.14]次治疗。牛支原体血清转化与抗生素使用之间的关联分析尚无定论。我们发现，在小圈舍（即同一空间最多50头犊牛）中采用桶饲，可限制牛支原体血清转化，并在犊牛育肥生产中减少抗生素的使用。
