Temtem Carolina, Kruse Amanda Brinch, Nielsen Liza Rosenbaum, Pedersen Ken Steen, Alban Lis
Faculty of Veterinary Medicine, University of Lisbon, Avenida da Universidade Técnica, 1300-477 Lisbon, Portugal.
Department of Large Animal Sciences, Section for Animal Welfare and Disease Control, University of Copenhagen, Grønnegårdsvej 8, Frederiksberg C, DK-1870 Denmark.
Porcine Health Manag. 2016 Oct 1;2:23. doi: 10.1186/s40813-016-0042-1. eCollection 2016.
There is growing concern about development of antimicrobial resistance due to use of antimicrobials (AMs) in livestock production. Identifying efficient alternatives, including vaccination, is a priority. The objective of this study was to compare the herd-level amount of AMs prescribed for weaner pigs, between Danish sow herds using varying combinations of vaccines against Porcine Circovirus Type 2 (PCV2), (MYC) and (LAW). It was hypothesised that herds purchasing vaccines, use these to prevent disease, and hence reduce their AM consumption, compared to herds purchasing fewer or no vaccines against these pathogens. Data summarised over year 2013 were obtained from the Danish Central Husbandry Register and the Danish VetStat database, in which prescriptions of medication are recorded. All one-site indoor pig herds with >50 sows and >200 weaners were selected. AMs prescribed for weaners was measured in animal daily doses (ADD) and divided according to three indication groups (gastro-intestinal, respiratory indication or total use). The analysis was based on three multivariable linear regression models of the herd-level ADD for each indication group. The eight vaccination combinations (2x2x2) were included as one explanatory variable, and herd size, measured as the number of weaner pen places was included in the models as a potential confounder.
Out of the 1513 herds in the study, 1415 had AMs prescribed for gastro-intestinal disorders, and 836 for respiratory disorders. PCV2 vaccines were purchased in 880 herds, MYC vaccines in 787 and LAW vaccines in 115 herds. Herds purchasing PCV2 and MYC vaccines had significantly more AMs prescribed than herds not purchasing vaccines or only purchasing LAW vaccines.
In the present study, using register data covering 1 year, we found an association between use of vaccination and increased amount of AMs prescribed for weaners. This does not exclude that the vaccines work, just that we were unable to detect this. The findings might be explained by some herds experiencing clinical problems associated with MYC or PCV2 despite use of vaccination. In other herds, it might reflect that vaccines applied to weaners are used for disease prevention in finishers rather than in the weaners. Information about vaccination protocols and herd health status was not available at the time of the study. Hence, further studies are required to investigate causality of the associations between use of AMs, vaccination practices and other confounding on-farm factors.
由于在畜牧生产中使用抗菌药物（AM），人们越来越关注抗菌药物耐药性的发展。确定包括疫苗接种在内的有效替代方法是当务之急。本研究的目的是比较丹麦母猪群中，针对断奶仔猪开具的抗菌药物在畜群水平上的使用量，这些母猪群使用了针对猪圆环病毒2型（PCV2）、支原体（MYC）和放线杆菌（LAW）的不同疫苗组合。研究假设是，与购买较少或不购买针对这些病原体疫苗的畜群相比，购买疫苗的畜群会使用这些疫苗来预防疾病，从而减少抗菌药物的使用量。2013年的数据汇总自丹麦中央畜牧登记册和丹麦兽医统计数据库，其中记录了药物处方。所有拥有超过50头母猪和超过200头断奶仔猪的单场室内养猪场都被选中。针对断奶仔猪开具的抗菌药物用量以动物每日剂量（ADD）来衡量，并根据三个适应症组（胃肠道、呼吸道适应症或总用量）进行划分。分析基于每个适应症组畜群水平ADD的三个多变量线性回归模型。八种疫苗组合（2×2×2）作为一个解释变量纳入，畜群规模以断奶仔猪栏位数来衡量，作为潜在混杂因素纳入模型。
在研究的1513个畜群中，1415个畜群有针对胃肠道疾病开具的抗菌药物处方，836个畜群有针对呼吸道疾病开具的抗菌药物处方。880个畜群购买了PCV2疫苗，787个畜群购买了MYC疫苗，115个畜群购买了LAW疫苗。购买PCV2和MYC疫苗的畜群开具的抗菌药物处方明显多于未购买疫苗或仅购买LAW疫苗的畜群。
在本研究中，利用涵盖1年的登记数据，我们发现疫苗接种的使用与针对断奶仔猪开具的抗菌药物用量增加之间存在关联。这并不排除疫苗起作用，只是我们无法检测到这一点。这些发现可能是由于一些畜群尽管接种了疫苗，但仍出现与MYC或PCV2相关的临床问题。在其他畜群中，这可能反映出给断奶仔猪接种的疫苗用于育肥猪的疾病预防，而不是断奶仔猪。在研究时无法获得有关疫苗接种方案和畜群健康状况的信息。因此，需要进一步研究来调查抗菌药物使用、疫苗接种做法与其他农场混杂因素之间关联的因果关系。
