Análise multivariada de varíaveis ambientais, fisiológicas, parâmetros comportamentais e produção e qualidade de leite de vacas no verão

Abstract

The objective of this study was to determine, through the multivariate analysis, which, among the environmental, physiological and behavioral parameters, influence milk production and quality of lactating cows. This study was developed with data from a collection carried out in 2009. Sixteen lactating Girolando cows were selected. The animals were divided into four treatments of 0, 10, 20 and 30 minutes on a cooling system. The statistical analysis used was the multivariate, using the technique of Principal Component Analysis on the environmental, physiological and behavioral parameters have influence on milk production and quality. The rumination was opposite to the production, indicating that it was smaller, because it presents a condition of possible stress. The CCS was strongly influenced by the TR and in turn the FR. Both TR and FR presented the highest values in time of 0 minutes indicating a condition of thermal stress, which reflected in accentuated values of CCS, reducing milk quality. The use of 10,20 and 30 min cow exposure times to the evaporative adiabatic cooling system provided significant changes in somatic cell counts.