Effect of Altering the Dietary Cation-Anion Ratio on Food Consumption and Growth of Young Chicks

Abstract

Eight-day-old chicks were used in a series of 3 experiments to study the effects of adding acid, base or a combination of these to an amino acid-corn-starch diet. The cation-anion ratio of the diet was reduced from 1.2 to 0.6 by adding increasing levels of L-glutamic acid hydrochloride and was increased from 1.2 to 2.4 with sodium or potassium carbonates or a combination of the two. Food consumption and weight gain were maximized when the ratio was in the range of 1.2 to 1.8. A ratio of 0.6 nearly completely inhibited growth. Sodium and potassium chlorides did not reduce food consumption or weight gain when added to the basal diet in equivalents equal to the highest level of hydrochloride. Excess calcium did not alleviate the growth depression due to excess chloride, whereas magnesium partially overcame the depression. The response of chicks to diets with ratios of greater than 1.8 depended upon the cation added. A combination of sodium and potassium was not detrimental but either cation alone reduced weight gain. It was found that the chick possesses kidney glutaminase I activity, but the activity of the enzyme did not increase when dietary acidity was increased.