70 FEEDS AND FEEDING, ABRIDGED 



quire more protein than mature animals. From a survey of the many 

 feeding- trials carried on by the experiment stations of this country, 

 the authors believe that 2-year-old steers should not be fed rations 

 wider than 1 :7 or 1 :8 when being fattened. Depending on their age, 

 fattening lambs should not be fed rations wider than 1 :5 to 1 :8. 

 (See Appendix Table V.) 



Factors influencing fattening. — The storage of fat in an animal 

 depends primarily upon the quantity of food consumed in excess of 

 maintenance and growth requirements. Fattening may take place at 

 any age, tho the tendency of young animals to grow greatly reduces 

 the proportion of food usually available for fattening. Supplying an 

 abundance of feeds that are palatable, concentrated, and largely di- 

 gestible aids rapid fattening, because a large surplus of nutrients 

 then remains after supplying the body needs. 



The disposition of an animal to fatten depends upon breed and 

 temperament. While a wild animal, nervous and active, can be fat- 

 tened only with difficulty, domesticated animals are more quiet and 

 usually fatten readily. The restless animal is rarely a good feeder, 

 while the quiet one, which is inclined to eat and lie down, will show 

 superior gains. This is not due to difference in digestive powers, but 

 rather to the fact that the quiet animal has, from a given amount of 

 feed, a greater surplus of nutrients for fat building. Fattening ani- 

 mals must not be allowed to exercise too much as this wastes nutrients 

 which they might store in their bodies. 



Returns from feed. — The following table ^ shows the amount of 

 food suitable for man returned by the different classes of farm ani- 

 mals from each 100 lbs. of digestible matter consumed : 



Human food produced from 100 lbs. of digestihle matter consumed 



Marketable Edible Marketable Edible 



Animal product solids Animal product solids 



Lbs. Lbs. Lbs. Lbs. 



Cow (milk) 139.0 18.0 Poultry (eggs) .... 19.6 5.1 



Pig (dressed) 25.0 15.6 Poultry (dressed) . 15.6 4.2 



Cow (cheese) 14.8 9.4 Lamb (dressed) ... 9.6 3.2 



Calf (dressed) 36.5 8.1 Steer (dressed) .... 8.3 2.8 



Cow (butter) 6.4 5.4 Sheep (dressed) ... 7.0 2.6 



The table, which presents one side of a most complicated problem, 

 shows that for 100 lbs. of digestible nutrients consumed the cow 

 yields about 139 lbs. of milk, containing 18 lbs. of solids, practically 

 all digestible. She easily leads all farm animals in her power to eon- 

 vert the crops of the field into human food. The pig produces about 

 25 lbs. of dressed carcass. Allowing for water, bone, and gristle, 

 there remains over 15 lbs. of edible dry meat. The steer and sheep 



6 Jordan, The Feeding of Animals. 



