Weber Nicolai Rosager, Pedersen Ken Steen, Hansen Christian Fink, Denwood Matthew, Hjulsager Charlotte Kristiane, Nielsen Jens Peter
University of Copenhagen, Faculty of Health and Medical Sciences, Department of Large Animal Sciences, Grønnegårdsvej 2, 1870 Frederiksberg C, Denmark.
University of Copenhagen, Faculty of Health and Medical Sciences, Department of Large Animal Sciences, Grønnegårdsvej 2, 1870 Frederiksberg C, Denmark; Øvet A/S, Køberupvej 33, 4700 Næstved, Denmark.
Prev Vet Med. 2017 Feb 1;137(Pt A):69-76. doi: 10.1016/j.prevetmed.2016.12.018. Epub 2016 Dec 29.
Previous research projects have demonstrated the need for better diagnostic tools to support decisions on medication strategies for infections caused by Escherichia coli F4 (F4) and F18 (F18), Lawsonia intracellularis (LI) and Brachyspira pilosicoli (PILO). This study was carried out as a randomised clinical trial in three Danish pig herds and included 1047 nursery pigs, distributed over 10 batches and 78 pens. The objectives of this study were: (1) to assess the effect of four 5-day treatment strategies (initiated at clinical outbreak of diarrhoea or at fixed time points 14, 21, or 28days after weaning) on average daily weight gain (ADG); (2) to compare the effect of treatment with doxycycline or tylosine on diarrhoea prevalence, pathogenic bacterial load, and ADG; (3) to evaluate PCR testing of faecal pen floor samples as a diagnostic tool for determining the optimal time of treatment.
(1) The four treatment strategies had a significant overall effect on ADG (p=0.01). Pigs starting treatment 14days after weaning had a significantly higher ADG (42 g) compared to pigs treated on day 28 (p=0.01). (2) When measured 2days after treatment, doxycycline treatment resulted in fewer LI-positive pens (p=0.004), lower excretion levels of LI (p=0.013), and fewer pens with a high level of LI (p=0.031) compared to pens treated with tylosine. There was no significant difference in F4, F18 and PILO levels after treatment with the two antibiotic compounds. There was a significant difference (p=0.04) of mean diarrhoea prevalence on day 21 of the study between pens treated with tylosine (0.254, 95% CI: 0.184-0.324), and doxycycline (0.167, 95% CI: 0.124-0.210). The type of antibiotic compound was not found to have a significant effect on ADG (p=0.209). (3) Pigs starting treatment on day 14 in pens where F4, F18, LI or PILO were detected by qPCR on the pen floor had a statistically significant increase in ADG (66g) compared to pigs treated on day 14 in pens where no enteric pathogens were detected (p=0.04).
The results of this study showed that the highest ADG was achieved when treatment was initiated 14days after weaning in pens where intestinal pathogens were detected. Doxycycline was more effective in reducing diarrhoea and LI excretion levels than treatment with tylosine.
先前的研究项目已表明，需要更好的诊断工具来辅助针对由大肠杆菌F4（F4）、F18（F18）、胞内劳森菌（LI）和毛样短螺旋体（PILO）引起的感染制定用药策略。本研究作为一项随机临床试验在丹麦的三个猪群中开展，纳入了1047头保育猪，分布在10个批次和78个猪栏中。本研究的目的是：（1）评估四种为期5天的治疗策略（在腹泻临床暴发时或断奶后14、21或28天的固定时间点开始）对平均日增重（ADG）的影响；（2）比较用多西环素或泰乐菌素治疗对腹泻发生率、病原菌载量和ADG的影响；（3）评估对猪栏地面粪便样本进行PCR检测作为确定最佳治疗时间的诊断工具的效果。
（1）四种治疗策略对ADG有显著的总体影响（p=0.01）。与在第28天接受治疗的猪相比，断奶后14天开始治疗的猪的ADG显著更高（42克）（p=0.01）。（2）在治疗后2天进行测量时，与用泰乐菌素治疗的猪栏相比，用多西环素治疗的猪栏中LI阳性猪栏更少（p=0.004），LI排泄水平更低（p=0.013），且LI水平高的猪栏更少（p=0.031）。用这两种抗生素化合物治疗后，F4、F18和PILO水平没有显著差异。在研究的第21天，用泰乐菌素治疗的猪栏（0.254，95%置信区间：0.184 - 0.324）和用多西环素治疗的猪栏（0.167，95%置信区间：0.124 - 0.210）之间的平均腹泻发生率有显著差异（p=0.04）。未发现抗生素化合物类型对ADG有显著影响（p=0.209）。（3）在猪栏地面通过qPCR检测到F4、F18、LI或PILO的情况下于第14天开始治疗的猪，与在未检测到肠道病原体的猪栏中于第14天接受治疗的猪相比，ADG有统计学显著增加（66克）（p=0.04）。
本研究结果表明，在检测到肠道病原体的猪栏中，断奶后14天开始治疗时ADG最高。与用泰乐菌素治疗相比，多西环素在减少腹泻和LI排泄水平方面更有效。
