The influence of clinical and chronic forms of magnesium deficiency on the haematological parameters of dairy cows

Abstract

The aim of the study was to determine the influence of hypomagnesaemia on the haematological status and predictive values of haematological tests in the diagnosis of magnesium (Mg) deficiency in dairy cow herds. The study was carried out on 100 dairy HF cows, divided into two experimental groups and a control one.The two experimental groups (I - clinical form of hypomagnesaemia, II - chronic form of hypomagnesaemia) consisted of 40 cows and the control group consisted of 20 healthy cows. Blood samples were collected twice: before the commencement of the therapy and after three months. In both hypomagnesaemic groups, low erythrocyte count, haemoglobin (Hgb) concentration and hematocrit (Ht) index values were observed. The indirect parameters of the erythrocyte system were within the standard reference range, with the exception of the mean corpuscular hemoglobin (MCH) index, which, in approx. 45% of animals, was below the lower limit of the normal range. Haemolytic normocytic normochromic anaemia was detected through the hypomagnesaemia of the cows. In the first and second group, at the first blood sampling an increase in the eosinophil count was observed, which was statistically significant in relation to the second sampling. In the blood smear test, a variety of erythrocyte sizes (anisocytosis), polychromasia and Howell-Jolly bodies were detected in the affected cows. After supplementation with magnesium, the concentration of Mg in the serum of the treated animals returned to normal more rapidly than the haematological parameters. The authors assumed that these in the haematological parameters may be helpful in indicating the need for Mg supplementation.