A leading US swine expert claims there is little or no control of the economically damaging porcine reproductive and respiratory syndrome (PRRS) in China.
Dr Cameron Schmitt of the Pipestone Veterinary Group, told delegates at the Leman Swine Conference in Nanjing, China, there are a great number of limiting factors which fail to curb the disease on Chinese pig farms. The event was organized by the University of Minnesota.
PRRS is the most ubiquitous of all pigs diseases and costs $700 million annually to control in the US alone. Dr Schmitt said PRRS challenges are daunting in China, which is the world's largest producer of pork. In 2012, China produced 50 million metric tons of pork which is five times the size of US production.
Dr Schmitt told delegates that laboratory analysis challenges are serious and widespread in China. Understanding the limitations of diagnostic results, as opposed to interpretation, often presents problems in PRRS samples brought to laboratories. Farms and outdoor pigs are scattered across China with little thought as regards PRRS implications. At the same time, there is scant understanding of biosecurity issues among Chinese pig farmers. Farms are often badly designed as regards pig biosecurity and disease prevention.
Dr Schmitt said knowledge of disease eradication principles is limited while vaccines are often overvalued by Chinese producers in terms of their efficacy. Sharing of hygiene and disease knowledge among Chinese pig producers rarely occurs and swine industry leadership is just beginning to emerge.
"There is a lack of quality control and quality assurance among many of China's veterinary laboratories. The disease tests are not standardized among the different laboratories. The report format can be difficult to read and much of the technology in Chinese veterinary laboratories is out of date," said Dr Schmitt."You can get different results at different labs as a result of split sampling. Effectively, swine practitioners are blind due to poor laboratory data and the lack of timeliness of results among other issues."
As the Chinese swine industry consolidates and the country moves toward a consumer society, farms will move out of urban areas into the country and will be larger and fewer in number. The value of well isolated sow farms well away from other pigs is just being realized. However, mega pig sites are a huge challenge to control, prevent and eradicate PRRS from.
Taking a benign attitude to PRRS is not conducive to success and for the most part has failed US pig production systems. Most have adopted a policy of eradication where possible and where it makes sense to do so. Dr Schmitt said vaccines are a tool to curb PRRS but they are not guaranteed to succeed.
"PRRS vaccines are a tool, just that. In 25 years of significant veterinary science, they are not perfect and frequently their value is overestimated. In the correct use, they can reduce lesions, clinical signs, and reduce losses, but they are not 100% effective," he added. "They do not prevent new virus introductions and are not a substitute for poor biosecurity. There is an obvious vacuum in modern progressive swine health management in China. But, as a whole, this is changing slowly for the better."