Quality of raw bulk-tank milk produced in northeast Brazil

The objective of this study was to evaluate the seasonal influence on the chemical composition, somatic cell count (SCC), and total bacterial count (TBC) of raw bulk-tank milk in northeastern Brazilian states. Data were obtained from milk samples from tanks collected monthly by industries registered with the Federal Inspection Service. According to normative instruction #62 (IN-62), two validity periods were considered. The highest recorded averages for chemical composition were between May and July. The mean fat content varied from 3.51% to 3.69%, and the protein content ranged from 3.07% to 3.17%. The averages of SCC ranged from 4.66 to 4.90 × 1,000 cells/ml, with the highest being recorded in July. At the same time, the TBC ranged from 2.34 to 2.53 cfu/ml. The highest TBC was recorded in March. The mean values of fat, protein, defatted dry extract, SCCs, and TBC were influenced by the months of the year. The means for these variables decreased in periods when Brazilian legislation was more severe. However, the SCC and TBC averages found in this study were still high, considering the quality of raw milk production. SCC and TBC presence still did not comply with the limits established by the legislation.