Second: What is the relative efficiency of different types of 

 animals as converters of waste energy into forms suitable for human 

 food? 



Third: How do the various conditions under which animals 

 may be kept affect their efficiency as producers of human food? 



The experiments here recorded relate chiefly to the second class 

 of problems above mentioned, viz., the influence of the type of 

 animal, their special subject being a comparison as meat producers of 

 the beef type of animal with the so-called "scrub," that is, with an 

 animal of mixed and unknown breeding but partaking of the 

 dairy type. Practical experience has shown that there is a distinct 

 financial advantage on the side of the specific beef type of steer, but 

 considerable diversity of opinion exists as to the real reasons for 

 this difference. 



Description of Experiments. 



Two steer calves were selected as the subjects of investigation. 

 One of these was a pure bred Aberdeen-Angus of typical beef form, 

 while the other was a "scrub" containing considerable Jersey blood 

 and possessing the dairy rather than the beef form. These animals 

 were about 8^2 and n months old respectively at the beginning of 

 the investigation in October, 1904, and were under nearly contin- 

 uous observation for over 2.^/2 years. During this time, with the ex- 

 ception of certain of the periods in which the balance of matter 

 and energy was determined by means of the respiration calorimeter, 

 they were fed an ordinary growing ration and while maintained 

 in a thrifty condition were not fattened. The feeding stuffs used 

 in each period were of the same kind for both animals and the dif- 

 ferent grains fed were mixed throughout in the same proportions for 

 each steer. The live weights of the animals were taken at least 

 weekly, as well as on three consecutive days at the end of each 

 month, and they were systematically measured and photographed 

 every three months. The accompanying photographs of the animals 

 on three different dates will serve better than words to illustrate the 

 character of the animals used. The measurements show that the 

 "scrub" increased more rapidly in length and height than did the 

 pure bred animal, the gain of the latter being more largely due 

 to increase in size of body. 



At intervals, the digestibility of the total ration and the nitro- 

 gen balance were determined for each animal. It was originally 

 intended to make these determinations once in three months, but 



(4) 



