The Nutrient Requirements for Laying-type Growing Chicks

Abstract

Two experiments were conducted to determine calcium and phosphorus requirements for White Leghon female starting chicks. Total 650 day-old chicks were fed the diets of various calcium and phosphorus for four weeks.The practical type basal diet was primarily composed of corn and soybean meal with 5% fish meal as a sole source of inorganic phosphorus, containing about 0.5% total phosphorus (inorganic phosphorus 0.1%) and 0.3% total calcium. 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 calcium requirement for normal growth and normal bone development was 0.83% in diet, which was a little lower than what was recommended by National Research Council. Total phosphorus required for normal growth and percent bone ash was 0.6 percent in diets. Optimum calcium: phosphorus ratio in diets was indicated to be 1.4:1.It was suggested that about 0.2% inorganic phosphorus was required for normal growth and bone development, and the availability of organic phosphorus appeared to be much higher than what had been thought.