Electrocardiographic Parameters of Normal Dairy Cows during Different Ages

Electrocardiograms were recorded from 60 clinically apparently healthy cross bred cattle in Andhra Pradesh of India. Cattle were divided into 3 groups based on their age i.e. cattle between 2 to 4 years age, 4 to 6 years age and 6 to 8 years age. The electrocardiograms were recorded on a bipolar base apex lead, using limb lead I. The duration and amplitude of the ‘P' wave, ‘QRS' complexes, ‘T' wave and the P-R, Q-T intervals and ST segment were measured in traced electrocardiograms. The value of ST segment in adults was significantly higher than young cattle, but the amount of ‘R' wave and ‘T' wave amplitudes in younger animals were significantly lower than older animals (P<0.05).