36 The Feeding of Animals 



normal, or below what was necessary to maintain the 

 tissues in their usual condition of rigidity. 



This leads to the observation that the water in a 

 growing plant is that which is in transit from the soil 

 to the air. This liquid stream enters the plant with 

 its load of building materials, takes into solution the 

 compounds elaborated in the leaves and aids in trans- 

 porting them to the points of rapid growth, finally 

 passing into the air from the surface of the foliage. 

 Throughout the entire growing season, the plant acts 

 as a pump, drawing from below through the roots the 

 water which it needs for various purposes, and dis- 

 charging it into the air. It was found that in Wis- 

 consin 309.8 tons of water was evaporated by the 

 plant for each ton of dry matter in the crop. Four 

 tons of dry matter per acre is not an unusual product 

 with maize, requiring 1,239.2 tons, or 10.4 inches of 

 water for its growth, the equivalent of about five -eigh- 

 teenths of an average annual rainfall. This is a fact of 

 great significance to the stock feeder. His success be- 

 gins with proper husbanding of the plant -food resources 

 of the farm, of which water is an important factor. 



Water in feeding stuffs. Cattle foods, whether in 

 the green or air-drj r condition, always contain more or 

 less water. The proportion is greatly variable, depend- 

 ing upon several factors. With the green foods, the 

 range of percentages is similar to that of the living 

 plants previously noted. As, however, forage plants 

 are used at varying lengths of time after cutting, and as 

 a loss of moisture begins immediately after the plant is 

 severed from its source of water supply, the amount of 



