The role of laboratory research in ensuring the biosafety of the farm

Abstract

 Relevance. The work is devoted to the study of the specifics of laboratory research in industrial pig breeding. The aim of the research was to determine the optimal sample sizes and methods of laboratory diagnostics to prevent the introduction of infectious disease agents with imported animals into the herd and a comprehensive assessment of the epizootic situation at the pig breeding enterprise.

Methodology. One of the key points of obtaining reliable laboratory results is the correctly determined sample size during sampling. When monitoring the welfare of imported livestock for infectious diseases, the most reliable studies will be the sampling of all imported animals. If it is not possible to take samples and study all animals when importing livestock, a sample can be used, while it is required to achieve a confidence of at least 95% and take into account that in a population of clinically healthy animals the prevalence of an infectious disease can be at the level of 5% or lower. For a group of 600 animals the sample size is 56. The sample size required to determine the disease in the affected herd was calculated with a similar 95% confidence level, but different disease prevalence levels of 10% (for Mycoplasma hyopneumoniae) and 30% (for Actinobacillus pleuropneumoniae). The sample sizes were 30 and 10 samples respectively.

Results. The analysis of the pathogenesis of infections of pigs Mycoplasma
hyopneumoniae and Actinobacillus pleuropneumoniae showed the risk of  introducing pathogens of these infectious diseases if only serological research methods are used to confirm the well-being of the supplier enterprise and conduct import quarantine. The selection of tissue samples for PCR studies from animals raised at the supplier and sent for slaughter increased the reliability of detecting infected animals. The developed scheme of monitoring studies with the use of ELISA and PCR methods for  porcine circovirus infection (CVIS) allows us to assess the epizootic situation for this disease, predict clinical manifestations and make timely adjustments to the scheme of preventive measures.