Food Requirements of Animals. 



249 



In this country, experiments with young lambs fed cow's milk 

 showed a gain in live weight of one pound for every 5.8 pounds 

 of milk consumed. If the milk contained 13 per cent of dry 

 matter, then 0.75 pound of milk solids produced 1 pound of in- 

 crease. This is a high food efficiency and practicaUy ten times 

 that shown with animals somewhat mature. This serves to il- 

 lustrate the rapid increase in tissue during the early periods of 

 growth. 



The kind of food most appropriate to the wants of the young 

 animal is revealed by the composition of milk. The first milk 

 secreted by the mother (colostrum) is very rich in protein, often 

 containing as high as 15 per cent. This gradually changes after 

 parturition and after a lapse of 8 to 10 days the composition of 

 the secretion becomes normal. Below is given the composition of 

 colostrum and the normal milk of our common farm animals. 



Percentage Composition of Colostrum Milk. 



Percentage Composition of Milk. 



The solid matter of milk has a high feeding value, because of 

 its complete utilization by the animal. It also supplies an abun- 

 dant amount of ash material for skeleton and tissue formation. 

 That each species has provided for the young a milk of such pro- 



