68 HOW THE ANIMAL USES ITS FEED 



While exercise requires more feed, a certain amount of 

 exercise is necessary to keep the animal in good physical 

 condition. The dairy cow requires a higher and more uni- 

 form temperature than the beef animal because she has 

 no protecting layer of fat. The skin and hair of the dairy 

 cow are also thinner than on beef animals. Milk secretion 

 is controlled by the nervous system of the animal, and 

 any shock to the nervous system such as that resulting 

 from exposure to cold cuts down milk production. 



Importance of Water. — Dairy cows require large quan- 

 tities of water, because milk contains about 87 per cent of 

 water. More water is also necessary to regulate the heat 

 of the body. The dry cow requires only about 65 per cent 

 as much water as the cow giving milk. The water supply 

 should be fresh, pure, and easily accessible. Some cow 

 stables are now equipped with drinking cups so that with- 

 out effort the cows can obtain drinking water at will. 



Feeding for Work Production. — Within certain limits, 

 the working capacity of the animal depends upon the 

 amount of food consumed over and above the amount 

 necessary for maintenance. Rations for work animals 

 should be such as will furnish the greatest amount of 

 energy. Concentrated feeds rich in digestible nutrients 

 supply this in most convenient form. Bulky feeds that 

 require a great deal of energy to digest leave but little 

 excess to be utilized in doing work. 



Nutritive Ratio. — The nutritive ratio is the ratio that 

 exists between the sum of the digestible fats and carbohy- 

 drates and the digestible protein in the ration or feeding 

 stuff. The nutritive ratio is found by multiplying the 

 digestible fat by 2^, adding the product to the digestible 

 carbohydrate material, and dividing the sum by the 



