472 



Journal of Agricultural Research 



Vol. IV, No. s 



The variations for the forms of phosphorus in the feces in percentage 

 of the amounts of the same forms ingested are marked, both within the 

 lots and between the lots. The cause of these variations is not apparent 

 from the data available. It is, however, evident that the forms of phos- 

 phorus of the feeds underwent profound changes during the processes of 

 digestion and metabolism. A large proportion of the acid-insoluble 

 phosphorus of the feeds was converted into acid-soluble phosphorus and 

 a large part of the soluble organic phosphorus was also changed into 

 acid-soluble inorganic phosphorus. 



PHOSPHORUS BALANCE 



The daily phosphorus balances of the lambs for the continuous 12 -day 

 metabolism test are given in Table XVII. 



Table XVII. — Daily phosphorus balances {in grams) of lambs in metabolism, test 



All of the lambs showed positive phosphorus balances. Even the low- 

 protein lot, which, on an average, ingested 3.14 gm. of phosphorus per 

 day, showed a balance of 0.224 gm. per day. These low-protein lambs 

 were fed the same feeds in the same quantities per 100 pounds of live 

 weight from weaning time, June 25, to January 28, a period of 217 days, 

 as they were fed during this metabolism test. During the main feeding 

 experiment they made an average daily gain of 0.28 pound per head 

 per day. From these satisfactory gains for a period of 7 months and 

 the positive phosphorus balance shown during the metabolism period of 

 12 days, it is probable that the phosphorus requirement for the normal 

 growth and fattening of lambs is not more than 3 gm. per day per 100 

 pounds of live weight. 



From the available data it is not apparent that there was any corre- 

 lation between the quantities of phosphorus stored and the quantities 

 of protein and phosphorus ingested. 



