Use of factor analysis in predicting epizootic process development in case of escherichiosis in calves

Abstract

Infectious diseases of young animals, including escherichiosis, cause certain economic damage to livestock. Natural, geographical and economic conditions have a certain influence on the occurrence and spread of escherichiosis. Factor analysis is a promising method for predicting possible changes in the epizootic process in calves with Escherichia coli taking into account the influence of a combination of various indicators. Escherichiosis of calves in the Amur Region was recorded in 23 sites located in the southern territorial zone with a continental climate and a developed livestock farming system. On five-year average, the morbidity in cattle was 0.13 ± 0.02%, and the mortality rate was 49.80 ± 5.09%. During the factor analysis, a correlation was found between the variables of the epizootic process, climatic and economic parameters. The analysis of variance revealed two groups of factors with a total variance of 77.18, which showed significant influence of the composition of factors on the epizootic process. The second factor with a variance level of 41.09% had a decisive influence on the behavior of the entire system. This factor was interpreted as climatic. When conducting a graphical analysis of the factor analysis results, it was found that the variables were located within an acute angle which showed the presence of a relationship between them. With an increase in both temperature and precipitation, there is a high probability of the occurrence and spread of escherichiosis in cattle. This fact was confirmed by the correlation coefficients. The correlation indices between the average annual precipitation and morbidity, the average annual temperature and morbidity were 0.26 and -0.38, respectively. Increasing number of animals per unit area as well as deviations from optimal temperature and humidity conditions may significantly increase the risk of escherichiosis. The prognosis of epizootic process development in case of calf ehrlichiosis allows taking a number of measures aimed at preventing the disease. In the areas of concern, the key point is specific prevention - vaccination of livestock. In areas with low incidence rates and favorable animal husbandry conditions, vaccination may not be mandatory. In such cases, the emphasis is on compliance with veterinary and sanitary standards, providing animals with a balanced diet. To increase the overall resistance of animals to infections, it is advised to use immunomodulators.