Effect of dietary calcium deficiency on the cardiac function of broiler chickens based on electro- and echocardiography

Abstract

To determine the effects of dietary calcium deficiency on the heart function of broiler chickens based on electro- and echocardiography, chicks were reared for 42 days and fed rations with different amounts of calcium. At 28 and 42 days of age, electrocardiographic and echocardiographic parameters were assessed. There were significant reductions of R wave amplitude (leads II and aVR) in the Ca-deficient group II at 42 day of age as compared to the control. S wave amplitudes were decreased in most leads but the decrease was significant (P < 0.05) only at 28 days (lead aVL, Ca-deficient group I) and 42 days (leads III, aVR, aVF, Ca-deficient groups I and II). T wave amplitudes were significantly (P < 0.05) decreased at 42 days (leads II, aVR and aVF) in the Ca-deficient group II compared to the control group. Variations in QT, ST and RR intervals were insignificant in the Ca-deficient groups compared with the control. There was a significant (P < 0.05) increase in left ventricular diameter at end-systole and a reduction of left ventricular fractional shortening in the Ca-deficient group II at 28 and 42 days as compared to the controls. Right ventricular fractional shortening was significantly (P < 0.05) decreased only in the Ca-deficient group II at 42 days of age. These results suggest that dose-dependent dietary calcium deficiency alters variations in electro- and echocardiographic parameters which could reflect decreased cardiac function in growing broiler chickens.