PROTEIN REQUIREMENT OF SHEEP. 



95 



growth of hair, the absolute difference, after all, does not add very greatly to 

 the total maintenance requirement. 



In Henneberg and Stohmann's Weende experiments 1 upon two sheep fed 

 exclusively on meadow hay, there was digested on the average per 1,000 pounds 



live weight: Pounds. 



Crude protein (total N X 6.25) 1.32 2 



Nitrogen-free extract 6. 28 



Crude fiber 3.93 



Ether extract . 32 



and the animal gained 0.17 pound of body protein, in addition to that stored 

 in the wool, and a small amount of body fat. 



In a series of 20 digestion and metabolism experiments by Schulze and 

 Marcker, 3 decidedly smaller amounts of protein proved sufficient to maintain 

 nitrogen equilibrium. In one case on a ration containing as little as 0.335 

 pound digestible crude protein per 1,000 pounds live weight, but having a very 

 wide nutritive ratio (1: 17.2) there was a slight gain of total protein, but one 

 less than the amount required for the growth of wool. If we exclude this 

 experiment and also 4 experiments in which it is evident that an excess of 

 protein was fed, we have as the average of 6 experiments in which no loss of 

 body protein was observed 0.653 pound digestible crude protein per 1,000 

 pounds live weight, while in two other experiments in which the minimum 

 losses of 0.005 and 0.015 pound body protein were observed, the protein supply 

 was, respectively, 0.655 and 0.690 pound. It is evident, then, that the protein 

 supply of the sheep can be materially reduced below the amount fed in Henne- 

 berg and Stohmann's experiments without leading to a loss of body protein. 



That such is the case seems to be clearly shown by the recent investigations 

 of Katayama at the Moeckern Experiment Station, 4 in which increasing amounts 

 of nearly pure protein (" aleuronat ") were added to a basal ration very poor 

 in protein, consisting of hay, oat straw, starch, and cane sugar. The protein in 

 every case was substituted for a corresponding amount of starch, so that the 

 total energy of the ration remained substantially unchanged. In the third 

 period of the experiment both of the two sheep showed some loss of body pro- 

 tein, while in the fourth period, with more protein in the food, a gain was noted. 

 In neither case was the growth of wool taken into consideration. By adding in 

 the one case the loss of body protein to the digestible protein of the food and 

 in the other period subtracting the gain, the author gets the following comparison : 



Protein requirement of sheep per day and head — Katayama. 





Sheep I 

 (weight, 34 

 kilograms). 



Sheep II 

 (weight, 38 

 kilograms). 



Period III: 



Nitrogen digested 



Grams. 

 1. 978 

 .079 



Grams. 

 2. 412 

 .216 



Loss of body protein 



Period IV: 



Nitrogen digested 



2. 057 



2.628 



3. 176 

 1. 107 



3.360 

 .515 



Gain of body nitrogen 



Average for maintenance 



2. 069 



2. 845 



2. 063 



2. 737 



Maintenance per 1,000 pounds live weight: 



Nitrogen 



.061 

 .379 



.072 

 .450 



Protein 





1 Neue Beitrage, etc. 



2 Estimated by Kellner to contain 1.04 pounds of true protein. 



3 Wolff : Die Ernahrung der Landwirtschaftlichen Nutztiere, p. 300. 

 * Die Landwirtschaftlichen Versuch-Stationen, vol. 69, p. 321. 



