Team examines biosecurity risks of public lands grazing

om Harris, University Center of Economic Development DirectorWhile the globalization of food networks helps feed individuals across the world, these networks can also aid in the spread of infection and disease among livestock. Outbreaks of avian influenza and mad cow disease reinforce the need for management practices that reduce the risk for disease outbreak. On the state level, many cattle producers in Nevada graze their herds on shared public lands. By putting various herds of livestock together on public lands, these animals are at an elevated risk for spreading or receiving disease.

To address the biosecurity risks of public lands grazing, researchers at the University of Nevada, Reno's College of Agriculture, Biotechnology and Natural Resources are developing strategies to help prevent the outbreak of disease in herds while helping to educate ranchers about these strategies.

One such disease being focused on by the research team is trichomoniasis, a venereal disease caused by a protozoa that affects the reproductive system of cattle. Professor Thomas Harris, director of the Center for Economic Development in the College of Business, says that trichomoniasis outbreaks can have numerous negative impacts on cattle operations.

"Trichomoniasis is passed from the bull to the cow, and infected animals may abort their calves," said Harris, whose work is also supported by Cooperative Extension and the Nevada Agricultural Experiment Station. "The disease can also affect a cow's ability to become bred for a long time, lowering herd pregnancy rates. These outcomes result in low calf crops for cattle producers, particularly in drought years, which negatively impact the incomes of cattle operations."

According to Harris, to eliminate the disease cattle producers often have to sell their entire herd. Certain state regulations may also prevent producers from entering into inter-state sales, putting additional economic burdens on the operation.

Typical cattle herd found throughout NevadaWhile it may be easier for a cattle rancher to monitor herd health on private land, cattle on public range are at a greater risks for contracting a disease from another herd. According to CABNR, a 2006 survey of cow-calf operations in Nevada indicated that 30 percent of producers do not test for trichomoniasis, and that only 37 percent reported they vaccinated their cattle against the disease.

Although UNR has worked to develop a vaccine against trichomoniasis, Harris' research seeks to investigate the factors and characteristics of ranchers that have opted to use the vaccine and other management practices to decrease the risk for trichomoniasis outbreaks. Using a survey of Nevada ranchers to collect information, Harris hopes the data can be used to better communicate the importance and benefits of treating trichomoniasis to Nevada ranchers who have not taken measures to protect their herds.

"We are interested in studying the producers that have already adopted the technology and tactics to prevent trichomoniasis," said Harris. "We want to know how they learned about these techniques and why they decided to use them. In understanding the characteristics of these adopters, we can develop better programs to reach out to other producers."

According to Harris, the preliminary data shows that local veterinarians and the University of Nevada Cooperative Extension helped convince producers to adopt trichomoniasis counter measures. While Harris' research focuses specifically on the trichomoniasis disease, the study has future implications for promoting awareness and solutions for other diseases that pose a threat to Nevada's cattle herds.