KARYOTYPAL VARIABILITY OF CARPATHIAN BROWN COWS
Authors: Starodub L. F. , Reznikova N. L. , Vysochansky J. S. 
Published: July 2021

Brown Carpathian breed of cattle bred in Transcarpathia at the end of the XIX century. and belongs to the breeds of dairy and meat productivity. Animals of the modern breed are direct descendants of the ancient Brown Carpathian cattle, common at one time throughout Central Europe. The main advantage of the Brown Carpathian breed is that it can be effectively grown on natural pastures – both in the lowlands and in the mountains. The genetics of these animals are resistant to acute infectious diseases, they are well adapted to local conditions, sensitive to improved housing and feeding conditions, and cows produce special milk, which is used in the manufacture of high quality hard cheeses and baby food. Animals of the Brown Carpathian breed belong to the local small domestic breeds and are in a state of significant risk. The uterine population is bred only in households.
The aim of our work was to study the karyotype variability of Brown Carpathian cows, which is quite relevant today. Cytogenetic analysis, which was aimed at establishing the karyotypic variability of Brown Carpathian cows, was performed in the village. Nyzhni Vorota, Volovets district, Zakarpattia region, in households. Purebred cows of Brown Carpathian breed – (16 heads) and local animals – (11 heads) were studied.
According to the results of cytogenetic analysis, genomic disorders, aneuploidy, were found in purebred cows of Brown Carpathian breed, which was 1.6% and was expressed mainly by hypoploid cells 2n = 56–58. For domestic animals, the frequency of metaphase plates with aneuploidy was 3.3%, which corresponds to a spontaneous level of cytogenetic variability.
Structural chromosome abnormalities, chromosomal breaks, in purebred cows were equal to 0.76%, which does not exceed the spontaneous level of chromosomal variability. In local animals, this variability did not manifest itsel.
The indicators of the micronucleus test (the proportion of lymphocytes with a micronucleus of 1.7–2.0‰, dinuclear lymphocytes 1.5–2.7‰, and the mitotic index of 4.8–5.5‰, respectively) in domestic animals are higher compared to purebred animals, however, do not exceed those of the species Bos taurus.
According to the results of the cytogenetic analysis, it was established that purebred cows of Brown Carpathian breed and their crossbreeds were characterized by quantitative and structural chromosome disorders.
Genomic disorders, aneuploidy, in local animals are 2 times higher (3.3%) compared to purebred cows of Brown Carpathian breed with a statistically significant difference in mean values (P > 0.99).
Low level or absence of structural disorders of chromosomes in purebred animals and their crossbreeds indicates a low degree of somatic mutagenesis.
The indicators of the micronucleus test, as an indicator of the effect of the total mutagenic load on the body of the studied cows, in domestic animals are higher compared to purebred animals, however, do not exceed those characteristic of the species Bos taurus.
It was established that the level of somatic mutagenesis is lower and the karyotype is more stable in purebred animals of the Brown Carpathian breed in comparison with the local ones.