Features of the biochemical composition of blood in cows of the Kholmogorsky breed with different levels of Holstein

As part of the experimental work, three groups of animals with varying degrees of Holstein were formed. The first group was characterized by blood content of 25...50% (n=15), the second – 51...75% (n=30), the third – 76...91% (n=15). It was found that cows with a Holstein level of over 75% had a 7.5% lower total protein level in their blood compared with animals with a blood content of less than 50% (P < 0.05). At the same time, in animals with a blood content of 25...50%, the concentration of triglycerides was 10.0% higher than in individuals with a higher degree of Holstein (P<0.05). AST in cows with a blood content of 50...75% was characterized by 19.9% (P<0.05) higher activity compared with less blood genotypes. In the first group, a significant number of cows had hyperproteinemia (33.4%), while the optimal ratio of protein fractions was found only in animals with a high degree of Holstein. The frequency of hypercholesterolemia ranged from 43.3% to 60%, ketonemia – from 20% to 40%, hyper- and hypoglycemia – from 6.6% to 13.3%, and hyperphosphatemia was found in almost all animals. The largest number of cows with increased AST activity was present in the second group, whereas in animals with less or more blood, this pathology was 2.0...2.7 times less common (P<0.05).