Interactive effects of dietary sodium and chloride on the incidence of spontaneous cardiomyopathy (round heart) in turkeys

Two pen trials were conducted in Utah, altitude 1,630 m, with Large White female turkey poults to evaluate effects of dietary Na and chloride (Cl) concentrations on live performance and deaths caused by spontaneous cardiomyopathy (STC, "round heart") from 0 to 35 d of age. A randomized block 2 x 2 factorial arrangement with four replicate pens per treatment was used. Pen size was 3.8 x 5.6 m. In each trial, four starter diets were formulated from a common basal diet (corn-soy-meat) to obtain the following sodium and chloride concentrations: High Na (0.24%):High Cl (0.40%); High Na (0.24%):Low Cl (0.16%); Low Na (0.14%):High Cl (0.40%); and Low Na (0.14%):Low Cl (0.16%). Supplements were NaCl, NaHCO3, NH4Cl, or combinations. After laboratory analysis, true values of Na were slightly lower than expected, Cl was near expected values to slightly low, and K was 1.145%. Body weight and feed conversion ratio at 35 d of age were unaffected in both trials. In both experiments, STC mortality was significantly reduced by the Low Na:High Cl treatment compared to the other treatments. In conclusion, a diet containing 0.10 to 0.12% Na and 0.38 to 0.40% Cl, significantly improved poult livability by reducing STC mortality without adverse effects on poult weight or feed conversion ratio.