FEEDING STUFF INSPECTION. 55 



FOOD NUTRIENTS AND THEIR USES. 



The valuable ingredients in animal foods are ash or mineral 

 matter, protein, fat and a class of compounds called carbohy- 

 drates, of which starch, sugar and crude fiber are the most 

 important examples. Although the ash or mineral matter is 

 essential to the well being of the animal, it is abundantly supplied 

 by most materials one is likely to feed, so what one most needs to 

 consider in buying and using cattle foods are protein, fat and 

 carbohydrates. 



A sufficient supply of protein in the food is indispensable. 

 The working animal depends upon it to replenish and repair its 

 working machinery, the growing animal to make muscle and 

 build up its whole system, the sheep to make wool and the milch 

 cow to make the casein and albumen of its milk. No other sub- 

 stance can take its place, or be manufactured into protein by the 

 body. When more protein is fed than is needed for the growth 

 and repair of the body, the excess performs the same functions 

 as the fats and carbohydrates. As a rule, however, this is not an 

 economical use to make of it. It is worth but slightly more than 

 the carbohydrates and about four-tenths as much as fat for this 

 purpose and is commonly the most expensive ingredient to pro- 

 duce or buy. 



The office of the other two substances, fat and carbohydrates, 

 is two-fold : First, they serve as fuel and are oxidized or burned 

 in the body to supply heat and force. The fat is worth about 

 two and one-fourth times as much as the carbohydrates for that 

 purpose. Second, they are used as material for making fat. 



Most of the home grown food materials are rich in carbo- 

 hydrates and relatively low in protein. Coarse foods, such as 

 hay, stover, silage, etc., are in general far less digestible than the 

 concentrated foods, such as oil meals, gluten meals, etc. 



The intelligent purchaser of concentrated foods will buy, as 

 far as possible, to supplement the home grown foods. Such a 

 man goes to the dealer in feeding stuffs primarily to buy such 

 foods as shall increase the digestible protein in the ration. 

 While all concentrated feeding stuffs carry that which will mate- 

 rially increase the digestible matter of the ration, the oil and 

 glmen meals are the richest in digestible protein, and thus it hap- 

 pens that the intelligent feeder of dairy stock usually buys this 

 class of foods. 



