The Nutrient Requirements for Laying-type Growing Chicks

VIII. Calcium and Phosphorus Requirements for White Leghorn Growing Chicks of 4-8 or 10 Weeks of Age

Abstract

Two experiments were conducted to determine calcium and phosphorus requirements for White Leghorn growing chicks. In the first experiment, twelve experimental diets of various amounts of calcium (0.5, 0.75, 1.0 and 1.25%) and phosphorus (0.48, 0.60 and 0.72%) were fed the female growing chicks of 4-8 weeks of age. In the second experiment, eight diets of various amounts of calcium (0.5, 0.75 1.0 and 1.25%) and phosphorus (0.48 and 0.60%) were fed the male and female growing chicks of 4-10 weeks of age. All experimental diets were primarily composed of corn and soybean meal with 3% fish meal, and graded levels of calcium and phosphorus were furnished by calcium carbonate and dicalcium phosphate. Calcium and phosphorus requirements were determined by measuring weight gain, feed efficiency and percent tibia ash.
It was indicated that the calcium levels required for normal growth and bone development was much lower in the cases of the lower phosphorus level (0.48%) in all the experiments. But in the lower phosphorus level, the growth of chicks fed the diets in higher calcium level (1.25%) was much lower.
In the higher phosphorus levels (0.60 and 0.72%) in the diet, the higher calcium level (1.25%) did not show the deterioration of the growth and feed efficiency.
It appeared that calcium and phosphorus requirements for the male chicks are much more than those for female chicks.
From the results of above experiments, it is recommended that the calcium and phosphorus requirements for the growing chicks of 4-8 or 10 weeks of age, should be 0.75% and 0.60%, respectively.