Purdue University	Mimeo. A. H. 182
Agricultural Experiment Station	September H, 1956
Lafayette, Indiana
Phosphorus Supplements for Swine 1/
C. E. Jordan, M. H. Kennington, M. P. Plumlee and W. M. Beeson
Department of Animal Husbandry
G-illis £t al. (2) reported a very detailed study of the comparative biological values of several inorganic phosphates for the growing chick* All supplements were compared with beta-tricalcium phosphate to which a value of 100 was assigned arbitrarily# The comparable value for dicalcium phosphate was 98, steamed bone meal from 70 to 100 depending upon the source, defluorinated phosphates from 82 to 99# Curacao Island Phosphate 87, and soft phosphate with colloidal clay less than 50# Chapman, e_t a_l. (3), reported a comparison of "soft phosphate-' steamed bone meal and dicalcium phosphate for growing swine. In their study, the feeding of "soft 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 fluorine content of the femurs# Gobble, e_t al., (4) reported that for growing fattening pigs the phosphorus of soft phosphate with colloidal clay was approximately equal in biological availability to the phosphorus of dicalcium phosphate# Conflicting data on the comparative value of phosphorus supplements has indicated a need for further research.
Swine rations high in corn and soybean oil meal and low in animal by-products feeds will usually contain from 0 * 25 to 0#30$ phosphorus, 50$ or so of which is so called "unavailable" or phytin phosphorus. The accepted phosphorus requirements of swine expressed as percent of the total rations are: 25 lb# pig, 0.60$; 50 to 150 lb# pig, 0.45$; 150 to 250 lb# pig, 0#33$ and all breeding stock, 0#40$. Thus, a phosphorus supplement should be and usually is added to such rations for all types of swine#
A deficiency of phosphorus causes a reduction in feed intake which will reduce gains and increase the feed required per pound of gain#
Also, it will reduce bone growth and calcification (results in softer bones)# This effect on the bones may or may not be observed from visual examination in the feed lot#
Purpose
The purpose of this study was to determine the comparative value of °he following phosphorus supplements as sources of phosphorus for young fast-growing swine:	dicalcium phosphate, monocalcium phosphate, steamed
uone meal, defluorinated rock phosphate, Curacao Island Phosphate, and soft phosphate with colloidal clay.
.-/ The research reported herein was supported in part by grants from the International Minerals and Chemical Corporation, Chicago, Illinois.^
1/ Cillis^ MoBo, LeCo Norris and Go F. Heuser. 1954- Journal of Nutrition V. 52 P, 115,
1/ Chapman, h!l. Jr., Jo Kastelic, G.C. Ashton and D.V. Catron. 1955.
1® Animal Science Vo 14, P® 1073®	,nc,
kf Cobble, J.Lo, RoC. Miller, G.W. Sherritt and Ho.I. Dunne. 1956.
Ta. Agric. Exot. Station. Bu. No. 609«