Initial and developed free fatty acid concentrations in milk from paired normal and septic subclinically mastitic udder quarters.

The free fatty acid (FFA) content of milk from the paired normal (N) and septic (Staphylococcus aureus or S. agalactiae) subclinically mastitic (SSM) quarters of dairy cows was determined by thin layer chromatography. Within-cow comparisons showed the FFA content of milk from the SSM quarters to be consistently significantly higher than that of the opposing N quarters: initially and after warm agitation and both rapid and slow cooling prior to storage at 4 degrees C for 48 h. No correlation existed between initial and post-treatment FFA levels in milk from N quarters, but a significant positive correlation in the case of SSM milks suggests their greater susceptibility to both spontaneous and induced lipolysis. There was no correlation between the somatic cell content and FFA levels of either freshly-drawn or processed SSM milk. The study emphasises the importance of healthy udders in the production of milk of acceptable flavour and aroma.