Monitoring of somatic cells in milk via laser analytical techniques for the early detection of mastitis

Mastitis is an inflammatory infection of the mammary glands in dairy cattle, which causes a pronounced increase in milk somatic cell count accompanied by changes in milk elemental and molecular composition. The aim of the present study was to use different laser analytical techniques for fast, accurate, and easy diagnosis of mastitis. Both laser-induced breakdown spectroscopy (LIBS) and laser-induced fluorescence (LIF) techniques were used for this purpose. The study was performed on milk samples taken from 150 Holstein cows. The results obtained by LIBS showed that in healthy milk (milk from uninfected cows), the intensities of calcium spectral lines were clearly higher than in mastitic milk samples. On the contrary, the intensities of the two sodium D-lines were higher in mastitic milk than in the healthy milk. A linear relationship exists between the sodium spectral line intensities and the average of corresponding somatic cell count (SCC). Adopting LIF, the fluorescence intensity was also found to correlate linearly with the SCC of milk samples. Comparing the two proposed laser analytical techniques with other conventional techniques showed that the proposed techniques are faster, much easier, cost-effective, and can be used in situ to monitor somatic cells for diagnosis of mastitis.