Food Needs of Fattening Steers 341 



constructive use of the food is largely in the direction 

 of fat -form ing. 



The extent of the actual production which occurs 

 can be closely estimated for any given case. It is 

 considered satisfactory if the rate of increase during 

 a reasonably long period of fattening is 2 Ibs. live 

 weight per day. This means the actual addition to 

 the dry substance of the body of from 1.3 to 1.5 Ibs. 

 Sometimes during short periods with excessive feeding 

 the daily gain may be 3 Ibs. live weight, and generally 

 after animals are well fattened, during the finishing 

 period, it may be as low as 1 Ib. or less. The actual 

 daily growth of new material may vary then, aside 

 from the water, from .6 to 2.25 Ibs. per day. Actual 

 fat formation may thus range from .4 to 1.8 Ibs. per 

 day. The proteid content of the increase, on the other 

 hand, probably does not exceed .3 Ib. daily in any in- 

 stance, and with mature animals it is very insignificant. 



The food needs of the fattening steer. In view of 

 the foregoing facts and of the prevailing views as to 

 the fat -forming function of carbohydrates, we can but 

 conclude that the non- protein part of the ration may 

 be the source of the chief part of the body substance 

 laid on by a fattening steer. The amount of protein 

 necessary for constructive work seems to be very small 

 with mature animals it is practically nothing. Our 

 theoretical point of view as to the nutrients which will 

 serve the purposes of a fattening animal is therefore 

 quite different from what it was when eminent author- 

 ities regarded protein as the main source of body fat. 

 It would seem, looking at the matter merely from the 



