Morpho-biochemical composition of blood and resistance indicators of breeding bulls of different breeds

Comparative morpho-biochemical studies of blood of breeding bulls of Holstein, Hereford and Aberdeen Angus breeds were carried out. There were no differences in the biochemical, morphological and mineral composition between the individuals of these breeds, as well as in the indicators of natural resistance. Certain disorders in protein, lipid and mineral metabolism were found in all three groups of bulls caused by errors in the conditions of feeding and keeping animals.