Recent studies have shown that intramammary infusion of Lactococcus does not cause inflammatory reactions; after intramammary infusion of Lactococcus, immune proteins acute phase proteins haptoglobin and milk amyloid A were significantly expressed in the mammary glands of healthy Holstein cows (Pyorala, 2003; Eckersall et al., 2006; Crispie et al., 2008), and no major bovine mastitis pathogen was detected (Pellegrino et al., 2017). Here, HP is linked to mastitis.