Effect of Mineral Mixture Composition on Chick Growth and Intestinal pH’s

Three experiments were conducted with growing chicks (1) to determine the optimum level of chloride necessary for the bioassay of protein quality of fish meals as the sole source of dietary protein, (2) to study the interrelation of high levels of sodium and potassium with the level of chloride and sulfate, and (3) to determine the effect of these ionic changes on the pH of the contents in different portion s of the intestines. The results indicate that fish meals when fed as sole source protein to chicks require very low dietary supplements of chloride or none at all to maximize growth. High levels of chloride in dietary mineral mixtures depress chick growth and can be overcome by increasing the sodium level. The growth depression due to high chloride level is aggravated if the sodium content is low and the potassium is high. A balance between dietary sodium and potassium levels must be maintained and also between these cations and the chloride content. No relationship was observed between the growth responses and the pH’s of the intestinal contents of the duodenum, jejunum and ileum. Evidently other factors are involved in the growth depression due to excessive dietary chloride level.