Abstract In an attempt to determine the effect of sodium chloride on chickens when fed at levels higher than those commonly recommended, some interesting effects on the hearts were noted. In this trial 100 twenty-five-day-old Peterson-White Rock cross chicks were used. The experiment was terminated after 10 days. A standard commercial 16% crude protein feed containing 0.5% iodized sodium chloride was used as a basic ration. To this, non-iodized sodium chloride was added at levels of 2%, 4%, 8%, and 12% of total ration. Ten battery brooders containing 10 chicks each were used. Two groups of 10 birds each were fed each of the rations with the varying salt levels. The birds were given unlimited water. Room temperature varied from approx. 80–95 degrees (F.). A bird from one pen on 8% added sodium chloride died after 2 days and another after 9 days on this ration. In one pen on…