The effect of the red blood cell system disorders on the further development and productivity of Holstein calves that had had bronchopneumonia

Abstract

The aim of this research was to study the effect of red blood cell system disorders on the further development and productivity of calves that had had bronchopneumonia. The study included 170 Holstein heifers at the age of 180-195 days: healthy heifers (n = 92) and heifers with moderate bronchopneumonia (n = 78). All animals had been under constant clinical supervision for 27 months. Blood sampling was performed in 10 animals from each group at the beginning of the experiment and on day 22, and also when they reached a body weight of 380 kg (the first artificial insemination), 30 days before the planned calving date, and on days 7, 90, 180 of lactation. The blood samples obtained were examined by a hematological analyzer, and the content of fetal hemoglobin was determined by Singer’s method. It was shown that after completion of the course of treatment the clinical symptoms of bronchopneumonia disappeared in calves, but microcytic hypochromic anemia appeared. Further, in these animals an increase was registered in the age of fruitful fertilization by 10.8% and of the insemination index by - 36.7%. After calving and during lactation, the severity of hypochromia decreased, but there was a tendency for macrocytosis, which, combined with increased anisocytosis, indicated hypoplastic anemia. This form of anemia occurred against the background of pathological residual changes after pneumonia due to the depletion of the compensatory potential of the bone marrow and its functional overload during lactation. The operational anemia revealed in lactating cows caused a decrease in milk productivity by 23.2-26.7% (P<0.01).