A Comparison of Phosphorus from Different Sources for Growing and Finishing Swine

Abstract

Two replicates of 18 pens of 4 pigs each (total 144 pigs) were fed in concrete drylot to determine: (1) the relative value of soft phosphate with colloidal clay, dicalcium phosphate and steamed bonemeal as inorganic phosphorus supplements for growing-finishing swine, (2) the effect of including these inorganic supplements at two different levels, (3) the effect of chlortetracycline upon the utilization of inorganic and organic phosphorus by the pig, (4) the ability of the pig to utilize phosphorus from plant sources (phytin phosphorus), and (5) to determine the comparative value of organic and inorganic phosphorus for the growing and finishing pig. Criteria of response were rate of gain, feed efficiency, daily feed intake and blood serum phosphorus when the pigs weighed 100 lb. These criteria, plus breaking strength, ash, phosphorus and fluorine content of the femurs were used when the pigs reached the terminating weight of 200 lb. A comparison of feeding colloidal clay with either steamed bonemeal or dicalcium phosphate resulted in a significant decrease in rate of gain, feed efficiency and breaking strength of femurs, accompanied by a significant increase in ash content and an increase in the fluorine content of the femurs.