Studies on the Phosphorus Availability of Various Phosphorus Sources for Laying-type Growing Chickens

Abstract

Two Experiments were conducted to compare the phosphorus availability of various phosphorus sources for the starting chicks of 0-4 weeks of age. The phosphorus sources tested in these experiments were feed grade dicalcium phosphate, defluorinated tricalcium phosphate, bone meal, isolated phytin and defatted rice bran. In the first experiment, each phosphorus source added to the corn-soy basal diet which contained three present fish meal as only animal protein source. The total phosphorus content was 0.48 percent in basal diet and 0.6 percent in all the experimental diets. In the second experiment, each phosphorus source added to the corn-corn starch-soy basal diet containing no animal protein feed. The phosphorus level was 0.38 percent in basal diet and 0.5 percent in all the experimental diets. The availability of phosphorus was measured by the body weight gain, feed efficiency and tibia bone ash.The results were as follow.1. The growth and bone ash of chicks fed defluorinated tricalcium phosphate were similar to those of chicks fed dicalcium phosphate in both experiments.2. In the lower dietary phosphorus level (0.5 percent), the growth of chicks fed bone meal was inferior to that of chicks fed dicalcium phosphate, but the bone ash was not significantly affected. In the normal phosphorus level (0.6 percent), the growth and bone ash of chicks fed bone meal was similar to those of the chicks fed other inorganic phosphorus sources.3. In the lower phosphorus level, the growth and bone ash of chicks fed isolated phytin were significantly lower than those of dicalcium phosphate, but in the normal phosphorus. level, phytin was effectively utilized as well as dicalcium phosphate.4. The growth and bone ash of chicks fed defatted rice bran as phosphorus source were significantly inferior to those of chicks fed dicalcium phosphate. It appears that phosphorus. in isolated phytin is much more available than that in defatted rice bran.