EN
The concentration of immunoglobulins (Ig) in colostrums at five subsequent periods (2, 24, 48, 72 & 96 hours after parturition) was monitored in 90 black and white cows in herds of the south Podlasie region. Estimates of colostral Ig were performed immediately after cow milking by means of a colostrometer. The objective of this study was to evaluate the effect of genotype, age of cows, season at calving, length of dry period and herds on the immunoglobulin content in cows colostrum (g/l). The mean immunoglobulin content at all investigated times was 38.3 g/l. A significantly higher (p ≤ 0.05) immunoglobulin content was found in the colostrums of multiparous cows, in cows with a high share (above 50%) of holstein-friesian genes and in cows with longer dry periods (over 60 days). Those results demonstrate the importance of monitoring colostrums’ quality in feeding of colostrums to calves for the purpose of optimizing passive immunity.