Nonlinear principal components of the biochemical profile of dairy cattle of five breeds

Abstract. The purpose of this study was to identify and explain patterns of biochemical parameters in dairy cows, taking into account the characteristics of their breed. Methods. A comparison was made of samples of animals of five breeds (Holstein, Tagil, Suksun, Sychevsk, Istoben) according to 17 biochemical parameters. The total number of animals studied was 407. To analyze the obtained results, statistical analysis methods were used, including the method of nonlinear principal component analysis using the CATPCA (Categorical PCA) algorithm. Scientific novelty. The chosen method made it possible to summarize a large number of biochemical indicators and identify processes in which the studied groups of cows differed to a greater or lesser extent. Results. Five principal components were identified and interpreted, explaining a total of 67.4 % of the total variance. Some observed patterns may indicate the development of pathological conditions in animals. Similar biochemical patterns were observed, on the one hand, in cows of the Tagil, Holstein and Suksun breeds, and on the other, in the Istoben and Sychev breeds. The animals of the Suksun breed were closest to the physiological norm. More pronounced changes associated with a negative energy balance were observed in Holstein cows.