FEEDING STUFFS 3 



Thus the five groups of nutrients may be divided or classified as water, 

 salts, albuminous substances, fats and carbohydrates. 



APPETIZERS are substances which, though possessing no nutritive 

 value, have the efifect of stimulating the appetite and secretion of digestive 

 fluids. In addition there should be recognized certain salts, ethereal oils, 

 bitter principles, vegetable acids and alkaloids (in small quantities). 



I. Water and Dry Matter 



The term "water" is in a general way applied to that constituent of 

 feeding stufifs which evaporates upon drying at a temperature of 102° C. 

 (215.6° F.). Loss from evaporation is not always limited to pure water, 

 but includes ethereal oils, as well as products of decomposition, such as 

 lactic acid, butyric acid, acetic acid, ammonia, etc., which should properly 

 be added to the residue. The residue represents the "dry matter." 



Feeding stufifs having a perfectly dry appearance, so-called air-dried 

 feeding stufifs, as grain, bran, meal, oil cake, hay and straw, contain a 

 certain amount of water, on an average 10 to 15 per cent. 



All green forages contain a high percentage of water, averaging from 

 75 to 90 per cent. The same is true of root crops and potatoes and their 

 factory waste products. Potatoes contain 70 to 75 per cent of water, 

 beets 80 to 85 per cent, beet pulp 90 per cent, distillery slop 94 per cent, 

 etc. 



The relative proportion of dry matter and water in the food require- 

 ments of dififerent species of animals varies thus : Horse, 1 to 2 or 3 : 

 ox, 1 to 4 or 5; sheep, 1 to 2; swine, 1 to 6 or 7. It is thus evident that 

 swine thrive best on the more succulent feeds, horses and sheep on com- 

 paratively dry feeds, and cattle on intermediate combinations. Feeds too 

 rich in water should be avoided. 



The water content of feeding stufifs aflfects their feeding value. Succu- 

 lent plants are less nutritious, or contain less nutrient material, than less 

 succulent or dry plants of the same species. Grasses from meadows or 

 pastures that were too wet (too much rain or irrigation) during the grow- 

 ing season contain more water and less dry matter and are consequently 

 less nutritious than when grown under opposite conditions. Forage plants 

 grown in the shade of trees or in other protected places usually contain 

 proportionately less dry matter than in the same species grown under 

 more natural conditions. 



A knowledge of the water content of feeding stufifs is important also 

 with reference to their keeping qualities. Feeding stufifs rich in water 

 spoil easily (slop and beet and potato pulp). Meals and oil cakes are 

 subject to decomposition and molding when they contain an excess of 

 water (over 14 per cent). 



Mold fungi predominate when the water content is between 15 and 30 

 per cent, while decomposition bacteria predominate when the moisture 

 exceeds 30 per cent. 



Determination of moisture content. — The substance to be analyzed should first 

 be finely ground in a small mill. Five or ten grams of the powdered product are 



