326 ANNUAL REPORT OF THE Off. Doc. 



they are born, and the younger the animal the greater the gain for 

 food consumed. 



The age at which animals are fed has a great deal to do with their 

 powers of assimilation. The younger the animal in general the less 

 the cost of production. Professor H. R. Smith in his recent book 

 on "Profitable Stock Feeding," gives the following figures: "Averag- 

 ing six different trials when accurate records were kept of gains and 

 cost of food it is found that during the first twelve months each 100 

 pounds of increase in live weight costs |3.45; the second twelve 

 months in the same animal |7.42; and the third twelve months 

 $11.50." 



At the Illinois Experiment Station a carload each of range bred 

 calves, yearlings and two-year-olds were fed. At the beginning of 

 the experiment the calves averaged 384 pounds, the yearlings 784 

 pounds, and the two-year-olds 1,032 pounds. The net cost of 100 

 pounds of gain was |4.10 on the calves, |5.60 on the yearlings and 

 |6.60 on the two-year-olds. 



The profits in beef production, however, consist not alone in the 

 increased weight of the animal but also in the enhanced value of the 

 original carcass. Thus if an eight hundred pound animal costs four 

 cents a pound and after being fattened sells for five cents a pound 

 there is a profit of eight dollars on the original carcass. On the 

 other hand, if the animal had originally weighed a thousand pounds, 

 this profit would have been ten dollars so there is an advantage in 

 favor of beginning with larger animals. This difference might easily 

 be offset, however, by the greater age of the larger animal. 



Where animals are grown for fattening the greatest profit will 

 nearly always be found in fattening as young as possible. If west- 

 ern animals are to be fed it will usually be found more profitable 

 to feed the larger ones, as long yearlings or two-year olds, on 

 account of the greater margin afforded by the heavier original 

 weight. 



The young animals are producing muscles and other living tissues 

 as well as fat. At the same time the carcass of the young animal 

 contains a higher percentage of water so that less food is required 

 for a pound of gain then than after the animal becomes older. The 

 muscles contain on the average about 66 per cent, water. There- 

 fore only one-third of the gain in muscle must be made from the food 

 eaten. On the other hand, the fatty tissue contains only about 10 

 per cent, water and must therefore be produced almost entirely from 

 the food. As the animals grov*^ older, cell activity decreases, growth 

 is not so rapid and the water-content diminishes. Young animals, 

 therefore, require a greater per cent, of protein and can use it to 

 better advantage than older ones. 



While muscle-producing foods may cost a little more per pound, 

 they will often be cheaper than those capable of producing fat alone. 

 Animals intended for beef production, should always be fattened 

 while growth is still active. Growth continues up to four or five 

 years although of course it is more rapid while younger, while in 

 general it may be said, the younger the animal the more nitrogenous 

 its ration; of course there is a possibility of making it too nitro- 

 genous to be profitable. Protein for maintenance and for growth is 

 all that is required. Any excess only goes to produce heat or fat 

 and for that purpose it is too expensive. It seems to matter little 



