PHOSPHORUS METABOLISM OF LAMBS FED A RATION 

 OF ALFALFA HAY, CORN, AND LINSEED MEAL^ 



By E. ly. Ross, Fellow in Chemistry, M. H. Keith, Assistant, and H. S. GrindlEy, 

 Chief, Division of Animal Nutrition, Department of Animal Husbandry, College of 

 Agriculture and the Agricultural Experiment Station of the University of Illinois 



INTRODUCTION 



The ultimate object of the investigations of which this article is a 

 partial report was to determine the influence of different quantities of 

 protein upon the nutrition of young growing lambs. The differences 

 in the amounts of protein consumed were secured by varying the pro- 

 portions of corn and linseed meal in the rations. Such differences in 

 the quantities of protein were therefore necessarily accompanied by cor- 

 responding differences in the quantities of phosphorus ingested by the 

 lambs. The experimental data relating to the phosphorus metabolism 

 of the lambs when weighing, on the average, 115 pounds are given in 

 this paper. For convenience, the original designation of the lots as 

 "low-protein," "medium-protein," and "high-protein" is retained- 



As to the relative availability of organic and inorganic phosphorus, 

 there is a wide difference of opinion among investigators. With regard 

 to lambs, there is some definite evidence of the assimilation of inorganic 

 phosphates of calcium in the work reported by Kohler and his associates.^ 



The question of the form in which the phosphorus is excreted is a 

 matter of interest, whatever the form of ingestion. Elimination in any 

 of the organic forms in which it was ingested would probably mean lack 

 of assimilation or incomplete use after assimilation. Giacosa ^ says that 

 all absorbed phytin is split with the formation of phosphates, part 

 of the phosphates appearing in the urine and part in the feces. Berg- 

 mann^ reports that the subcutaneous injection of glycerophosphate in 

 lambs was followed by complete elimination as inorganic phosphates. 



It is usually said that in herbivora phosphorus is eliminated almost 

 entirely by way of the intestine. Bergmann^ found complete elimi- 



• The authors wish to acknowledge their indebtedness to Prof. W. C. Coffey and Mr. A. D. Emmett, 

 of the University of Illinois, for helpful suggestions and assistance in the planning and conducting of this 

 experiment. 



2 Kohler, A., Honcamp, F., Just, M., et al. tj'ber die Assimilation des Kalkes und der Phosphor- 

 saure aus verschiedenen Kalkphosphatcn durch wachsende Tiere. In Landw. Vers. Sta., Bd. 6i, Heft 

 s/6, p. 451-479- 1905. 



and Eisenkolbe, P. Weitere Untersuchungen iiber die Assimilation der Phosphorsaure 



und des Kalkes aus Kalkphosphaten durch wachsende Tiere. In Landw. Vers. Stat., Bd. 65, Heft 

 s/6, p. 349-380. 1907. 



3 Giacosa, P. Sulla fitina (sale calcico-magnesiaco dell' acido anidrossimetilendifosforico) e suo com- 

 portarsi nell' organismo. In Gior. R. Accad. Med. Torino, ann. 67, no. 7/8, p. 414-416. 1904. 



* Bergmann, W. Ueber die Ausscheidung der Phosphorsaure beim Fleisch- und Pflanzenfresser. In 

 Arch. Exp. Path. u. Pharmakol., Bd. 47, Heft 1/2, p. 77-81. 1901. 



Journal of Agricultural Research, Vol. IV, No. 5 



Dept. of Agriculture, Washington, D. C. Aug. 16, 1915 



111.— I 

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