Short communication: Changes in micromineral, magnesium, cytokine, and cortisol concentrations in blood of dairy goats following intramammary inoculation with Staphylococcus aureus.

Abstract The aim of this study was to investigate mineral metabolism and immune response in dairy goats following intramammary inoculation with varying doses of Staphylococcus aureus . Blood samples were collected at 0, 2, 4, 8, 12, 24, 48, and 72h after intramammary inoculation. Lowered plasma Fe concentrations were observed from 12 to 24h postinoculation in groups SAA ( Staph. aureus at 10 4 cfu, n=5) and SAB ( Staph. aureus at 10 8 cfu, n=5). Plasma Cu concentrations increased in group SAB 2h after inoculation and maintained greater concentrations until the end of the experiment compared with the control group (phosphate-buffered saline, n=5). Increased plasma Zn concentrations in group SAB were observed 48h after inoculation, and the concentration was still greater 72h after inoculation compared with the control group. Greater plasma Mg concentrations were detected in groups SAA and SAB compared with the control group at all timepoints after inoculation. Plasma Mg concentrations were generally greater in group SAA than in group SAB through 72h (except at 2h). Plasma tumor necrosis factor-alpha concentrations were unchanged following intramammary inoculation with Staph. aureus throughout the study. Plasma IL-6 concentrations in groups SAA and SAB increased gradually compared with the control group and peaked at 48h after inoculation. In group SAB, serum cortisol concentrations started to increase from 8h postinoculation and peaked at 12h postinoculation. In conclusion, increasing the inoculum dose does not induce more rapid proinflammatory cytokine responses, whereas the data indicate that mineral metabolic alterations occur during the course of Staph. aureus mastitis in the goat.