Concentration of lactoferrin and immunoglobulin G in cows' milk in relation to health status of the udder, lactation and season.

The aim of this study was to analyze an effect of udder health status, somatic cell count (SCC), stage and number of lactations, and different seasons on the concentration of lactoferrin (LF) and immunoglobulin G (IgG) in quarter milk samples (n=120) from crossbreed (Lithuanian Black-and-White & Holstein) dairy cows. Quarter health status was based on SCC and microbiological analysis. The highest mean value of LF and IgG were observed in quarters with subclinical mastitis 0.1 ± 0.02 mg/ml and 0.41 ± 0.06 mg/ml, respectively. Grouping the data according to SCC revealed increased LF (0.07 ± 0.01 mg/ml as against 0.06 ± 0.01 mg/ml) and IgG values (0.27 ± 0.05 mg/ml as against 0.23 ± 0.02 mg/ml) in DQ (SCC from 201,000 ≥ 401,000 cells/ml) compared to HQ (SCC up to 200,000 cells/ml). The milk LF and IgG levels were effected by stage of lactation (p<0.01 and p<0.05, respectively) and season of the year (p<0.001 and p<0.001, respectively). Nevertheless, SCC and subsequent lactation (p>0.05) had no effect on these immunity components.