| The general aim of the thesis was to increase our knowledge of serum globulin and its relationship with various chemical and hematological parameters in dairy cows. Serum globulin as part of the immune system can reflect inflammation, infectious disease and nutritional status of dairy cow.;Specific objectives of this study were (1) to compare colorimetry-based total serum globulin values with electrophoretically-determined serum globulin fractions and with IgG concentration, and to evaluate diurnal and long-term physiological variation and the effects of lactation and venipuncture site on serum globulin concentrations in Holstein dairy cattle. (2) To verify the relationship between the number of transferable embryos (TE) and serum globulin concentrations of cows after superovulatory treatment. (3) To aggregate serum globulin observations into distinct groups using a classification method based on distance to cluster centroids and demonstrate that variations of serum globulin concentration can adequately predict variations of other parameters, which might be involved in globulin variation.;Serum total globulin and albumin concentrations were analyzed by colorimetry and electrophoresis in 86 lactating cows; IgG concentrations were determined by radial immunodiffusion test in 41 dry and 34 lactating cows. In this experiment (article 1) colorimetry-based total serum globulin concentrations correlated well with gamma-globulin fractions (r2 = 0.87) and IgG concentrations (r2 = 0.91). Diurnal variation of total serum globulin concentration was significant ( P = 0.01); however, globulins did not vary significantly over a 15-week period. Mean serum globulin concentration in samples obtained from the jugular vein was 2.35 g/L higher (P < 0.0001) than that of samples obtained by coccygeal venipuncture.;Forty nine Holstein cows (41 lactating and 8 dry) were subjected to superovulatory treatment for commercial production of embryos. At the time of embryo harvest, individual blood samples were taken from each cow for analysis of biochemical parameters. Feed samples were collected daily during two weeks before embryo collection and they were analyzed for mycotoxins (vomitoxin, zearalenone and T2 toxin). In this experiment (article 2) serum globulin had no significant effect (P = 0.14) on the number of transferable embryos.;These studies show that colorimetric method widely used in routine laboratory analyses remains a useful test for globulin determination in dairy cattle. However, sampling time and venipuncture site should be considered in the interpretation of serum globulins. Serum globulin was not associated with the number of transferable embryos, and finally, centroid method was more successful than linear discriminant function to describe how different blood parameters varied with high or low globulin concentration. Centroid classification showed that serum concentration of Fb, Na, Cl, P, Crea and Ca and Neutro, Lym and RBC counts of GLO 0 were significantly different from GLO+ and GLO - categories. |
