Social network analysis for the assessment of pig, cattle and buffalo movement in Xayabouli, Lao PDR

The aim of this study is to understand the role that the movement patterns of pigs, cattle and buffalo play in the spread of foot-and-mouth disease (FMD). A cross-sectional survey consisting of a questionnaire was used in a hotspot area for FMD: Xayabouli Province, Lao People’s Democratic Republic. A total of 189 respondents were interviewed. We found that the key players in this network were people who were involved with more than one species of animal or occupation (multipurpose occupational node), which represents the highest number of activities of animals moved off the holding (shown with the highest out-degree centrality) and a high likelihood of being an intermediary between others (shown with the highest betweenness centrality). Moreover, the results show that the animals moved to and away from each node had few connections. Some nodes (such as traders) always received animals from the same group of cattle owners at different times. The subgroup connection within this network has many weak components, which means a connection in this network shows that some people can be reached by others, but most people were not. In this way, the number of connections present in the network was low when we defined the proportion of observed connections with all possible connections (density). These findings indicate that the network might not be busy; only one type of node is dominant which enables increased control of disease spread. We recommend that the relevant authorities implement control measures regarding the key players, which is the best way to effectively control the spread of infectious diseases

Influences on variation in fertility of sows : a thesis submitted in partial fulfillment of the requirements for the degree of Master of Philosophy, Massey University

This thesis presents the results from a series of studies related to factors influencing fertility of sows in New Zealand. The conclusion from an analysis of longitudinal pig reproductive performance data is that summer-autumn infertility was not a significant problem on the farms included in this study during the time period investigated. In New Zealand there are probably certain specific conditions when seasonal infertility does become a problem for a particular pig herd, and this may be more evident on farms in the South Island which are using a group housing husbandry system for their sows. The intervention trials into increased dry sow ration in newly mated sows and of the management technique of split weaning both failed to demonstrate these techniques improved reproductive performance. Economic simulation modelling suggests that while there does not seem to be an overall benefit from the increased dry sow feed intake, it would yield an economic benefit on some farms. Possible explanations for this are discussed in this thesis. The investigation into the usefulness of ultrasound scanning for determining early pregnancy status in sows demonstrated the effectiveness of this diagnostic technique in detecting pregnancy, but did not show a level of loss of early pregnancies sufficient to justify more intensive investigation of embryonic mortality. Cull sows sent to slaughter were examined for their pregnancy status and any pathological changes. A large proportion of these animals showed endometritis and urinary tract pathology, indicating that both of these conditions were more common in the cooperating herds than had been suggested by earlier clinical evidence

Analyses of Contact Networks of Community Dogs on a University Campus in Nakhon Pathom, Thailand

Free-roaming dogs have been identified as an important reservoir of rabies in many countries including Thailand. There is a need for novel insights to improve current rabies control strategies in these countries. Network analysis is commonly used to study the interactions between individuals or organizations and has been applied in preventive veterinary medicine. However, contact networks of domestic free-roaming dogs are mostly unexplored. The objective of this study was to explore the contact network of free-roaming dogs residing on a university campus. Three one-mode networks were created using co-appearances of dogs as edges. A two-mode network was created by associating the dog with the pre-defined area it was seen in. The average number of contacts a dog had was 6.74. The normalized degree for the weekend network was significantly higher compared to the weekday network. All one-mode networks displayed small-world network characteristics. Most dogs were observed in only one area. The average number of dogs which shared an area was 8.67. In this study, we demonstrated the potential of observational methods to create networks of contacts. The network information acquired can be further used in network modeling and designing targeted disease control programs

Field Studies Evaluating Bait Acceptance and Handling by Free-Roaming Dogs in Thailand

(1) Background: As part of the ongoing endeavor to eliminate dog-mediated human rabies in Thailand, renewed interest has been shown in oral vaccination of dogs as a supplementary tool to increase vaccination coverage of the dog population. (2) Methods: Three different bait types were tested using a hand-out model on the campus of the Kasetsart University and the surrounding temples in Thailand during September 2017, consisting of two industrial manufactured baits (fish meal and egg-flavored) and one bait made from local material (boiled pig intestine placed in collagen casing). A PVC-capsule containing dyed water was inserted in the bait. (3) Results: The fishmeal bait was significantly less often accepted and consumed (50.29%) than the other two baits (intestine bait—79.19%; egg bait—78.77%). Delivery and release of the dyed water in the oral cavity was highest in the egg-flavored bait (84.50%), followed by the intestine bait (76.61%) and fishmeal (54.85%) baits. Bait acceptance was influenced by sex, age, and body size of the dog. Also, the origin of the dogs had a significant effect: temple dogs accepted the baits more often than street dogs. (4) Conclusion: A significant portion of the free-roaming dog population in this study can be vaccinated by offering vaccine baits

Prevalence and risk factors of brucellosis and dairy farmers’ KAP in 2 townships, Myanmar

Brucellosis is a highly infectious zoonotic disease and has a great economic impact on dairy production. In Yangon Region of Myanmar, 0.47% seroprevalence of brucellosis in dairy cattle and 8 human IgG positive cases was reported. This study aims to determine the prevalence of brucellosis in dairy farms and its risk factors as well as to assess the current knowledge, attitudes and practices (KAP) of dairy farmers regarding brucellosis. Our study was conducted in Hlegu and Taikkyi Township during September 2019 to January 2020. Pooled milk samples were collected from 174 dairy farms. Using Milk Ring Test (MRT), Brucella spp. was found in 30 dairy farms and the prevalence was 17.2%. Statistically significant farm factors associated with MRT positive results were farm location in Takkyi Township (Odds ratio (OR) 3.19; 95%CI =1.42, 7.15), pasture sharing (OR 3.43; 95%CI = 1.34, 8.76), and abortion (OR 2.68; 95% CI = 1.21, 5.98). Survey for the KAP for brucellosis in farmers indicated that good knowledge, attitudes and practices were in 35.1, 99.4, and 62.1% of the respondents, respectively. In conclusion, brucellosis was still a problem of dairy farms in study area and MRT can be used as a farm level screening test. Educational campaign for brucellosis prevention and control should be considered according to a lack of knowledge and inappropriate farm practices among dairy farmer

Prediction of the spread of African swine fever through pig and carcass movements in Thailand using a network analysis and diffusion model

Background African swine fever (ASF) is a serious contagious viral disease of pigs that affects the pig industry. This study aimed to evaluate the possible African swine fever (ASF) distribution using network analysis and a diffusion model through live pig, carcass, and pig product movement data. Material and Methods Empirical movement data from Thailand for the year 2019 were used, and expert opinions were sought to evaluate network properties and the diffusion model. The networks were presented as live pig movement and carcass movement data at the provincial and district levels. For network analysis, a descriptive network analysis was performed using outdegree, indegree, betweenness, fragmentation, and power law distribution, and cutpoints were used to describe movement patterns. For the diffusion model, we simulated each network using spatially different infected locations, patterns, and initial infection sites. Based on expert opinions, the initial infection site, the probability of ASF occurrence, and the probability of the initial infected adopter were selected for the appropriated network. In this study, we also simulated networks under varying network parameters to predict the infection speed. Results and Conclusions The total number of movements recorded was 2,594,364. These were divided into 403,408 (403,408/2,594,364; 15.55%) for live pigs and 2,190,956 (2,190,956/2,594,364; 84.45%) for carcasses. We found that carcass movement at the provincial level showed the highest outdegree (mean = 342.554, standard deviation (SD) = 900.528) and indegree values (mean = 342.554, SD = 665.509). In addition, the outdegree and indegree presented similar mean values and the degree distributions of both district networks followed a power-law function. The network of live pigs at provincial level showed the highest value for betweenness (mean = 0.011, SD = 0.017), and the network of live pigs at provincial level showed the highest value for fragmentation (mean = 0.027, SD = 0.005). Our simulation data indicated that the disease occurred randomly due to live pig and carcass movements along the central and western regions of Thailand, causing the rapid spread of ASF. Without control measures, it could spread to all provinces within 5- and 3-time units and in all districts within 21- and 30-time units for the network of live pigs and carcasses, respectively. This study assists the authorities to plan control and preventive measures and limit economic losses caused by ASF