406 



NUTRITION OF FARM ANIMALS 



responding ages. The experiments do not show, however, that 

 these amounts might not have been still further reduced. 



TABLE 97. DIGESTIBLE PROTEIN PER 1000 POUNDS LIVE WEIGHT. 

 ARMSBY AND FRIES 



Henry and Morrison 1 likewise report the results of unpub- 

 lished experiments by Haecker in which growing fattening 

 steers made satisfactory gains on amounts of digestible protein 

 intermediate between those recommended by Kellner for beef 

 and for dairy breeds. 



On the other hand, Fingerling's investigations on calves 

 4-j-i 1 months old, already cited in a discussion of the utiliza- 

 tion of feed protein (471), indicate that a much lower level of 

 protein supply may be adequate to support normal growth. 



The experiments 2 were made upon four grade or full-blood Sim- 

 menthaler calves from four to seven months old at the beginning of 

 the trials, and belonging to early-maturing strains. The rations fed 

 consisted of a basis of hay or straw, or both, to which were added in 

 varying proportions wheat gluten, peanut oil and starch with the 

 necessary amount of salt. The protein supply was varied by varying 

 the amount of wheat gluten, the energy values of the rations being 

 kept as nearly identical as possible by corresponding changes in the 

 starch and oil. The experiments were intended to test the necessity 

 for the relatively large amounts of protein called for by the current 

 standards and also the influence of a deficient energy supply upon the 

 gain of protein. 



As appears from Table 87, the medium rations, supplying in 

 the neighborhood of 1.2 pounds of protein per 1000 pounds 

 live weight, were clearly sufficient to meet the demands of 

 the maximum possible protein gain, since an increase of the 



1 Feeds and Feeding, isth Ed., p. 670. 2 Landw. Vers. Stat., 76 (1912), i. 



