Tracking sources of microbiologic contamination of raw milk during milking process in dairy farms from Agreste of Pernambuco

Abstract

The procedures employed in milking process are determinant for obtaining milk with good microbiological quality. The study of contaminant microorganisms permits the identification of its source, what allows the adoption of control measures that will conform to the standards established by legislation. The aim of this work was to determine main points of milk microbiological contamination during milking process. For that mesophilic aerobes (MA), psychrotrophics (PS), coagulase positive Staphylococci (CPE), total coliforms (TC) and Escherichia coli (EC) were quantified in different steps of milking in six dairy farms and one communitarian bulk tank on Agreste region of Pernambuco, between august and september of 2005. Poor microbiological milk quality was indicated by the high counts of the groups of microorganisms studied. The average counts of microorganisms in milk samples from the dairy farms were 8,3 x 10⁶ (MA), 2,6 x 10⁷ (PS), 1,3 x 10⁴ (CPE), 2,5 x 10⁵ (TC) and 3,7 x 10³ (EC). In the milk collected from the communitarian bulk tank  counts were 6,1 x 10⁷ (MA), 3,4 x 10⁷ (PS), 6,5 x 10⁴ (CPE), > 1,5 x 10⁴ (TC) and 2,0 x 10³ (EC).Most contaminated points found were residual water of cans, the bottom of cans, bulk tank, teats, first three jets of milk, teatcups, bucket and milker’s hands, and the main cause of milk contamination is improper employ or the absence of good hygiene practices during milking process.