C6 A STUDY OF FARM ANIMALS 



the carbon is left to be made up into the solid part of the 

 plant which serves as the more bulky material of food. 



Nitrogen in the form of a compound is taken up by the 

 plant through its roots; but plants of the legume group, such 

 as the clovers, cowpeas or soy beans, aided by certain bac- 

 teria, have the power of using the nitrogen in the soil atmos- 

 phere. Nitrogen is a highly valued plant food, and the 

 farmer often purchases it in fertilizer at a good price. These 

 different elements unite with one or more others in the plant, 

 and form combinations which are familiar to us under vari- 

 ous names. Of these, the following are important when we 

 come to consider the plant as food. 



Water is a combination of hydrogen and oxygen. It is 

 found in all plants, and even in very dry hay. To get the 

 water entirely out of the plant, it must be driven out with 

 artificial heat. The amount of water in plants differs greatly. 

 Common timothy hay and red clover contain about 15 per 

 cent, and ordinary corn meal has a similar amount. About 

 80 per cent of green pasture grass is water, and some of our 

 roots, like the turnip, have 90 per cent. After the water is 

 driven from the plant by heat, what is left is dry matter. 

 The water in the plant is worth no more than any other 

 water, its chief value being to carry food in solution through 

 the plant from the root to the farthermost leaf. 



Ash, or mineral matter, of plants, we see, for example, in 

 the ashes left from burned wood. When we burn a plant, 

 we destroy its form, and all that which burns and disappears 

 we call organic matter. That which is left is ash, or inorganic 

 matter. There is much difference in the amount of ash in 

 plants. Green or very young plants contain the least, and 

 old ones the most. Common corn fodder contains about 3 

 per cent of ash, alfalfa about 10 per cent, and some of the 

 roots as little as 1 per cent. The ash in plants is of value 

 for food, if not too abundant. Hogs raised on feeds contain- 

 ing but little mineral matter, such as corn, for example, do 



