MAINTENANCE REQUIREMENTS OF MATTER 329 



417. Protein requirement of swine. The determinations 

 of the fasting katabolism of swine recorded in Chapter VIII 

 (377) gave an average of 0.48 Ib. per thousand pounds live 

 weight for the fasting protein katabolism of swine, although 

 with a considerable range in the individual results. McCollum 1 

 has reported considerably lower figures for the protein katab- 

 olism of swine receiving no protein but fed liberal amounts of 

 starch, the mean of twelve experiments being 0.26 Ib. per 

 1000 pounds live weight with a range of 0.14 Ib. -0.33 Ib. 

 Whether, however, such small amounts as these are sufficient 

 for actual maintenance, or if not, what excess above them is 

 necessary, has not been certainly determined. 



In the experiments of Von d. Heide and Klein (378), in one of 

 which an approximate maintenance ration was fed to three young 

 swine, there was a material gain of protein by the animals. The 

 amounts actually katabolized, however, as shown by the amount of ni- 

 trogen excreted in the urine, were as follows for the three animals 

 together : 



Dietrich, 2 in his experiments upon maintenance ration of swine 

 (378), found that 0.70 to 0.84 Ib. of digestible protein per thousand 

 pounds live weight sufficed to produce nitrogen equilibrium in two 

 periods following an eight-day fasting period, but that about the same 

 amounts (0.80 to 0.90) previous to the fasting period were insufficient, 

 while in two trials in which respectively 0.94 and 1.06 Ib. were con- 

 sumed protein maintenance was reached. 



418. Protein requirement of the horse. In the experiments 

 by Grandeau and LeClerc described in Chapter VIII (386 d), 



1 Wis. Expt. Sta., Research Bui. 21. 



2 Ills. Expt. Sta., Bui. 163 (1913)- 



