Аge and hereditary factors affecting the hematological parameters of the Hereford cattle

Blood testing of beef cattle is relevant due to the peculiarities of keeping animals in conditions requiring a high level of adaptation. Hereford cattle tolerate extremely low and high temperatures well; however, for breeding cattle it is important to evaluate animals not only by productivity, but also by interior features, including hematological parameters. The aim of the study was a comparative assessment of the blood parameters of breeding cattle of the Hereford breed in the parental and daughter generations. The study was conducted in a breeding farm located in the foothill zone of the Maslyaninsky District of the Novosibirsk Region. The object of the study was the hematological parameters of peripheral blood of Hereford cows and heifers (mother-daughter pairs) kept outdoors all year round in the foothill pastures of the south of Western Siberia. The age of the cows was 3-5 calving, the age of the heifers was 17-18 months. Blood counts in the maternal and daughter generations were analyzed, and the total number of parent-descendant pairs was 66 pairs. It has been established that the hematological parameters of cows and heifers in the conditions of foothill pastures in the south of Western Siberia are within the reference values with a sufficiently high variability of all signs. Significant differences between the indicators of mothers and daughters under the condition of the same type of maintenance, feeding and the period of blood sampling indicate the presence of the influence of the age of animals rather than environmental conditions. At the same time, a fairly high level of heritability of hematological parameters was found, primarily related to the blood's ability to transport oxygen, which can be used as a criterion for the animals' adaptability to extreme conditions.