Erythrocytes and features of the relationship of their level with metals and metalloids in the body of heifers

The assessment of the age variability of erythrocytes and their morphofunctional characteristics, estimated by the value of erythrocyte indices in the body of Holstein black-and-white breed heifers, is given, and the dependence of their parameters on the concentration of metals and metalloids in the blood is determined. It was found that the number of erythrocytes, hematocrit and hemoglobin in the blood of animals decreases with age within the limits of the norm by 34.35, 20.68 and 24.51 %. The value of MCV and MCH increases by 20.81 and 14.87 %, but the MCN decreases by 4.84-7.09 %. The level of iron and manganese in the blood of heifers increases by 29.58 and 23.52% with age, corresponding to the norm, and the concentration of copper, zinc and cobalt, although increasing, does not reach its lower limits. The amount of nickel in the blood of animals increases by 3.0 times, exceeding the average standard value established for the zone of the Southern Urals, but lead and cadmium, increasing by 2.24 and 3.25, do not reach the average reference value. Blood iron correlates with the amount of hemoglobin (r= -0.69±0.25 - -0.72±0.24) and the value of MSN (r= 0.62±0.27 - 0.74±0.23); zinc with hemoglobin (r= -0,70±0,24 ‒ -0,76±0,23); co-balt with erythrocytes (r= -0.61±0.28 ‒ -0.72±0.25) and MCV (r= 0,54±0,29 ‒ 0,77±0,22).