Season influence on milk physico-chemical and microbiological aspects in Western Santa Catarina

Abstract

The objective of this study was to analyze the influence of seasonal changes on milk quality in Western Santa Catarina, Brazil. Dairy farms (799) had raw milk samples (9144) collected and analyzed for fat, protein, SCC (somatic cell count) and TBC (total bacterial count). Samples were collected from cooling tanks on the farm during the months of October 2009 to September 2010 and grouped into four seasons (summer, autumn, winter, and spring). The data were classified according to the normative instructions 51 and 62 the Ministry of Agriculture, Livestock and Food Supply, and also according to a quality pay system adopted by the dairy industry in the region of the study. The results revealed differences between groups (P<0.05), where fat content was higher in autumn, protein and TBC were higher in winter and SCC showed the highest rates in the summer. According to the criteria established by legislation, the main quality problem was the TBC, with higher counts in the winter, and in the summer we observed the highest percentage of non-compliant samples. For the quality payment system, chemical composition resulted on better prices to be paid to producers, while TBC was primarily responsible lower price.