A traditional cattle trade network in Tak province, Thailand and its potential in the spread of infectious diseases Chamrat Khengwa A , Papaspong Jongchansittoe B , Poonyapat Sedwisai C and Anuwat Wiratsudakul C,D,E A Tak Provincial Livestock Office, Mahathaibumrung Road, Rahang, Maung, Tak. B Mae Hong Son Provincial Livestock Office, Khunlumprapas Road, Jongkam, Maung, Mae Hong Son, Thailand. C The Monitoring and Surveillance Centre for Zoonotic Diseases in Wildlife and Exotic Animals, Faculty of Veterinary Science, Mahidol University, Phutthamonthon 4 Road, Salaya, Phutthamonthon, Nakhon Pathom, Thailand. D Department of Clinical Sciences and Public Health, Faculty of Veterinary Science, Mahidol University, Phutthamonthon 4 Road, Salaya, Phutthamonthon, Nakhon Pathom, Thailand. E Corresponding author. Email: anuwat.wir@mahidol.edu Abstract. Cattle in Thailand are traded by cattle dealers in the cattle markets through informal negotiation processes. The present study aimed to explore a traditional cattle trade network and its potential in the spread of infectious diseases. A cross- sectional questionnaire-based survey was conducted in cattle markets located in Tak province, Thailand. A static weighted directed one-mode network was constructed and geographic locations of sources and destinations of animals were plotted. A total of 210 cattle dealers responded to the questionnaires. The cattle trade network contained 112 sources and destinations of animals and 168 trading activities. The highest generalised weighed in- and out-degree centralities and k-core were observed in the same cattle market at 53.4, 106.7 and 4, respectively. Spatially, cattle dealers could transport animals as far as 774.4 km from the original markets and natural barriers such as mountainous areas tended to dictate the trading routes, premises of animals and magnitude of trading activities. Traditional cattle trading patterns described in this study pose some important challenges to veterinary authorities in tailoring effective prevention and control measures for confronting infectious diseases. This study quantitatively analysed the traffic within a network of cattle trade and found a wide range of spatial movements and a high connectivity of markets to sources and destinations of animals, which may accommodate the spread of infectious diseases within the network. This peace time network analysis could help related authorities to better focus on possible infected premises and to immediately respond once an epidemic occurs. Additional keywords: centrality, epidemiology, livestock, social. Received 27 January 2015, accepted 2 August 2015, published online 4 September 2015 Introduction Agriculture has played an important role in Thai economics and life style. One-third of the households across Thailand work in agricultural sectors and 93% reside in remote areas. The two major agricultural activities are crop cultivation and integrated crop-livestock farming. The majority of livestock produced in this country are pigs, chicken and cattle (Charoensook et al. 2013). In 2009, the number of cattle in Thailand was estimated at 8 595 428 but the average number of cattle per household was only 6.2 head indicating that the majority of cattle owners are small holders (Charoensook et al. 2013) and the cattle are produced under traditional extensive grazing systems before being sold to the cattle dealers. The cattle trading system in Thailand is still managed in a traditional way meaning that the trades are mainly based on oral negotiation without any official documentation. In this trading system, cattle are transported live by the dealers from the farmers’ premises to cattle markets where informal negotiation between cattle dealers and purchasers takes place (Department of Livestock Development (DLD) of Thailand 2014a). Hence, cattle originating from different sources gather in the same markets for trading. Live animal movement and gathering in such traditional cattle trade networks may allow infectious diseases to spread to different locations, and the trade network structure determines how fast a disease may spread (Rautureau et al. 2010). The relationship among pairs of farms or premises can be analysed as a ‘network’ and animal movements within the network can be determined as paths on which infectious diseases can spread. The structure of the network and network topology may allow us to study how a disease diffuses in a large- scale population and to further identify animal populations or premises that are potentially exposed to infection. Ones that are CSIRO PUBLISHING Animal Production Science, 2017, 57, 152–160 http://dx.doi.org/10.1071/AN15043 Journal compilation Ó CSIRO 2017 www.publish.csiro.au/journals/an