Multivariate relationship between major constituents and casein fractions in buffalo milk using canonical correlation analysis

This study explored the multivariate relationship of protein, fat, lactose, minerals, water, and milk urea nitrogen (MUN) with major casein (CN) fractions in buffalo milk using canonical correlation analysis (CCA). Two sets of milk chemical constituents were produced: the first group was composed of variables related to CN fractions (e.g., aS2-CN, aS1-CNB, aS1-CNA, k-CNX2, k-CNX1, and b-CN; canonical variate U) and the second group contained variables associated with major milk components (e.g., fat, lactose, protein, minerals, water, and milk urea nitrogen (MUN); canonical variate V). A major canonical correlation (R = 0.946) was obtained by using the CANCOR procedure of SAS, whose significance (P <0.01) was verified by the Wilks' Lambda test. Exploration of the major canonical correlation, revealed for the canonical variate U, the following canonical loadings for CN fractions: b-CN = 0.619, aS2-CN = 0.361, aS1-CNB = 0.314, k- CNX1 = 0.137, k-CNX2 = 0.056, and aS1-CNA=0.004. Regarding canonical variate V, the canonical loadings for major milk components were the following: protein = 0.936, water =-0.685, fat = 0.474, lactose =-0.286, minerals = 0.226, and MUN = 0.068. Hence, when buffalo's milk composition is explored from a multivariate approach, an increase in protein, fat, and minerals, as well as a decrease in water and lactose may result in increased CN fractions, mainly b-CN, aS2-CN, and aS1-CNB. A better understanding of the multivariate relationship among milk chemical components may provide insights for designing future efficient animal nutrition models to accurately modulate the milk chemical composition of buffaloes, which may be useful for improving the technological properties of the milk for this species. (c) 2023 Elsevier Ltd. All rights reserved.