Relationship between blood haemoglobin and serum iron concentrations and heart girth in pre-weaned dairy calves

The aim of the research was to study the relation between blood haemoglobin (Hb) and serum iron (Fe) concentrations and changing of heart girth with age in calves. Blood samples of 66 dairy calves were taken at the age of 3, 5 and 16 weeks (wks). Blood samples were analysed for Hb and serum Fe concentration. At each bleeding, the heart girth was measured. The lowest mean concentration of Hb was measured at the age of five wks. The concentration of serum Fe and heart girth increased with age. Significant positive correlations were found between Fe concentration at 3 wks of age and heart girth of calves at 5wks (r=0.270; P=0.032) and between Fe concentration at 5 wks and heart girth of calves at 5 (r=0.283; P=0.021) and 16 wks (r=0.284; P=0.028). The lowest Hb concentration recorded at 5 wks, might suggest that this is the most critical period for developing anaemia in calves. The correlations established between heart girth and Fe concentration at different ages indicate that serum Fe concentration has some influence on changing of heart girth in calves.