Mastitis is an inflammation of the mammary gland that affects dairy cows, causing losses to the dairy sector. Alternatives to conventional treatment are extensively investigated. The objective of this work was to evaluate in cows the milk quality parameters when an innovative infrared LED device was coupled to the milking machine. Four cows (n = 16 teats) from the Fazenda Escola da Universidade Estadual de Londrina were monitored before, during, and after being milked for 4 consecutive days, totaling 8 milkings with a photobiomodulation device with 36 infrared LEDs adapted to each teat cup unit in a commercial milking machine. The optical dosimetry was a power density (PD) of 41.8 mW/cm2 and an energy density (ED) of 10 J/cm2 per animal corresponding to an ED of 2.52 J/cm2 per teat. Milk samples were collected weekly to evaluate the quality and health parameters of the mammary gland under light irradiation. No changes in the milk quality were observed with the ED applied, maintaining the same physicochemical characteristics. New studies should be conducted with other EDs to establish possible preventive and therapeutic effects of photobiomodulation in mastitis cows.