Systemic inflammatory biomarkers and somatic cell count in dairy cows with subclinical mastitis

Systemic parameters and its relationship with Somatic Cell Count (SCC) in dairy cows were evaluated. Cows that presented subclinical mastitis (SMC; n = 16) and healthy cows (HC; n = 6) were selected and identified by the California Mastitis Test and SCC in milk. SCC results were logarithmically transformed into somatic cell score (SCS). HC presented SCS 〈 4.32 while SMC presented SCS 〉 4.32. Milk and blood samples were collected in three days: D1 (first day of sampling), D2 (48 h after D1) and D3 (7 days after D1), to determine White Blood Cells (WBC), albumin, total protein, total bilirubin and malondialdehyde (MDA). Results were expressed as mean ± standard deviation. It was considered significant at P < 0.05. The data of SCS on D1, D2 and D3 in SMC were: 6.8 ± 1.7, 6.4 ± 1.8, and 6.3 ± 2.0, respectively. In SMC the MDA (nmolL^-1) were: D1 - 9.3 ± 2.6, D2 - 8.6 ± 2.4, and D3 - 11.5 ± 3.5. The MDA on D3 in SMC (11.5 ± 3.5) were increase when compared to HC (6.0 ± 1.3) (P < 0.001). No significant difference was found in WBC, TP, ALB, and TB between groups. It was observed a positive correlation between MDA-SCS (ρ = 0.4) and between WBC-SCS (ρ = 0.3) in the SMC group. It was concluded that the systemic repercussion damage in the mammary gland promoted by subclinical mastitis in dairy cows can be assessed using the MDA and WBC biomarkers.