A collaborative work between the University of Minnesota, UC- Davis, and Pipestone Veterinary Services was published this past month in the journal Frontiers in Veterinary Science.
Between-farm animal movement, despite being an essential factor of infectious disease spread is not currently recorded in the US. The objective of this project was to create a model to predict animal movement based on between-site distance, ownership, and production type of the sending and receiving farms. The model was able to predict animal movement in the south-central region of the study area with a high aggregation. It also showed an overlap with the distribution of outbreaks of porcine reproductive and respiratory syndrome (PRRS) in this area.
Abstract: Between-farm animal movement is one of the most important factors influencing the spread of infectious diseases in food animals, including in the US swine industry. Understanding the structural network of contacts in a food animal industry is prerequisite to planning for efficient production strategies and for effective disease control measures. Unfortunately, data regarding between-farm animal movements in the US are not systematically collected and thus, such information is often unavailable. In this paper, we develop a procedure to replicate the structure of a network, making use of partial data available, and subsequently use the model developed to predict animal movements among sites in 34 Minnesota counties. First, we summarized two networks of swine producing facilities in Minnesota, then we used a machine learning technique referred to as random forest, an ensemble of independent classification trees, to estimate the probability of pig movements between farms and/or markets sites located in two counties in Minnesota. The model was calibrated and tested by comparing predicted data and observed data in those two counties for which data were available. Finally, the model was used to predict animal movements in sites located across 34 Minnesota counties. Variables that were important in predicting pig movements included between-site distance, ownership, and production type of the sending and receiving farms and/or markets. Using a weighted-kernel approach to describe spatial variation in the centrality measures of the predicted network, we showed that the south-central region of the study area exhibited high aggregation of predicted pig movements. Our results show an overlap with the distribution of outbreaks of porcine reproductive and respiratory syndrome, which is believed to be transmitted, at least in part, though animal movements. While the correspondence of movements and disease is not a causal test, it suggests that the predicted network may approximate actual movements. Accordingly, the predictions provided here might help to design and implement control strategies in the region. Additionally, the methodology here may be used to estimate contact networks for other livestock systems when only incomplete information regarding animal movements is available.
This past month, the Morrison group invited Dr. Paul Yeske, swine practitioner at the Swine Vet Center (St. Peter, MN), Dr. Amanda Sponheim, PhD candidate at the University of Minnesota and Support Veterinarian at Boerhinger Ingelheim, and Dr. Maria Pieters from the University of Minnesota to discuss the latest progress made in successfully eliminating Mycoplasma hyopeumoniae from swine herds. Dr. Pieters is the head of the MycoLab at the College of Veterinary Medicine and focuses on diagnostics and epidemiology of swine mycoplasms to help veterinarians control associated diseases.
- History of Mycoplasma hyopneumoniae herd elimination and practices: podcast
- Sampling techniques and protocols to use during the process of elimination: podcast
- Starting the elimination: when is day zero? podcast
The podcasts in the press
The STEMMA laboratory at the University of Minnesota and more particularly Dr. Alvarez’s team is aiming at monitoring of antimicrobial resistance in animal and human bacteria. Therefore, the research they present in this article published this month, focused on Salmonella species both in swine and cattle. Records from the Veterinary Diagnostic Laboratory between 2006 and 2015 were compiled to study the evolution of the proportion of resistant strains of Salmonella in Minnesota.
Dr Hong, in collaboration with researchers from the U of MN, captured the number and the type of antimicrobials each strain was resistant to. He also monitored the evolution of the resistances over the nine-year period.
Evolution in antimicrobial resistant Salmonella isolates
recovered from swine at the MVDL in 2006–2015.
Explanation of the figure: Proportion of Salmonella isolates recovered from swine samples that were resistant to ampicillin (A), ceftiofur (C), enrofloxacin (E), florfenicol (F), gentamicin (G), neomycin (N), oxytetracycline (O), sulfadimethoxine (Sul), spectomycin (Sp) and trimethorpim/ sulfamethoxazole (Ts)
Abstract: Salmonellosis remains one of the leading causes of foodborne disease worldwide despite preventive efforts at various stages of the food production chain. The emergence of multi-drug resistant (MDR) non-typhoidal Salmonella enterica represents an additional challenge for public health authorities. Food animals are considered a major reservoir and potential source of foodborne salmonellosis; thus, monitoring of Salmonella strains in livestock may help to detect emergence of new serotypes/MDR phenotypes and to gain a better understanding of Salmonella epidemiology. For this reason, we analyzed trends over a nine-year period in serotypes, and antimicrobial resistance, of Salmonella isolates recovered at the Minnesota Veterinary Diagnostic Laboratory (MVDL) from swine (n = 2,537) and cattle (n = 1,028) samples. Prevalence of predominant serotypes changed over time; in swine, S. Typhimurium and S. Derby decreased and S. Agona and S. 4,5,12:i:- increased throughout the study period. In cattle, S. Dublin, S. Montevideo and S. Cerro increased and S. Muenster became less frequent. Median minimum inhibitory concentration (MIC) values and proportion of antibiotic resistant isolates were higher for those recovered from swine compared with cattle, and were particularly high for certain antibiotic-serotype combinations. The proportion of resistant swine isolates was also higher than observed in the NARMS data, probably due to the different cohort of animals represented in each dataset. Results provide insight into the dynamics of antimicrobial resistant Salmonella in livestock in Minnesota, and can help to monitor emerging trends in antimicrobial resistance.
2016 was a great year for the swine group at the University of Minnesota. The Food Centric Corridor Infectious Disease Research Laboratory was remodeled to create an open and luminous space to foster collaboration between researchers. The Leman conference and Leman China were tremendous successes, sharing research-based solutions to swine veterinarians and producers in Minnesota and around the world. The new animal isolation units construction has started and will be achieved next year, allowing our scientists to perform cutting edge research on infectious diseases. Our researchers have made great discoveries and shared them with the community.
Thanks to all of you who are supporting the swine group, 2016 was indeed a great year and we hope 2017 will be even better.
We wish you a very happy holiday season and all the very best for 2017!
The University of Minnesota highly values its partnerships with the industry stakeholders. With the objective to continue a fruitful and mutually beneficial collaboration, the College of Veterinary Medicine (CVM) and the College of Food, Agricultural and Natural Resource Sciences (CFANS) at the University of Minnesota hosted the Minnesota Pork Board (MPB) Research Committee on December 15th, to exchange ideas and to discuss projects that would be the most beneficial for the swine industry in Minnesota.
After a review of the current and future swine projects happening at both Colleges, Dean Ames (CVM), and Dean Buhr (CFANS) gave an update on the new facilities being built on the St. Paul Campus including the new animal isolation units that will allow our scientists to perform cutting edge research on infectious diseases.
Lastly, the MPB research committee toured the newly remodeled Food Centric Corridor Infectious Disease Research Laboratory as well as the Veterinary Diagnostic Laboratory.
The U of MN would like to thank all the representatives from the Minnesota Pork Board who came to meet our researchers and made this day the great success it was.
Presentation from the swine researchers
Visit of the Veterinary Diagnostic Laboratory with Dr. Torrison
The new animal isolation unit
Interdisciplinary research to address grand challenges related to food animals, primarily swine
Fruitful discussion between the UofM and the MPB