The Availability of Soybean Oil Meal Phosphorus for the Rat

Abstract

The 14% blood fibrin ration of Klein has been shown to be an excellent low phosphorus ration (0.028%). Properly supplemented, this ration is capable of sustaining satisfactory to excellent growth rates during the rapid growing period of the young rat. Evidence is presented which indicates that the phosphorus requirement of the young rat during this period lies between 0.256 and 0.328% of the ration. Soybean oil meals prepared either by the expeller or solvent process, contained 0.66% phosphorus of which 58% was in the form of phytin or phytic acid. The remainder exists as inorganic, phospholipid, and nucleic acid phosphorus. The phosphorus of soybean oil meal was readily available for growth and bone formation. Additional heat apparently had no measurable effect on the availability of the phosphorus. The phosphorus of casein was likewise readily available. Regardless of the level of phosphorus ingested the bone ash contained approximately 18% phosphorus. The protein of soybean oil was nearly equal to that of blood fibrin and both of these proteins were superior to casein when they were fed at levels of 14.0%. The data further indicate that soybean oil meal protein when properly supplemented with vitamins including choline does not require cystine and methionine in supplemental amounts greater than that supplied by the trace of these substances present in 1% 1:20 liver powder.