FEEDS AND FEEDING 81 



Nutrients 



The groups of food materials are called nutrients. To a 

 certain extent, at least, these nutrients may replace one another, 

 although no nutrient can take the place of protein for building 

 tissue and preparing waste of nitrogenous materials in the body. 

 The fats and carbohydrates perform similar functions, and 

 to a large extent, carbohydrate materials may replace fat in 

 the food, even when a large fat production is demanded of the 

 animal. 



To supply food in the right proportions to meet the various 

 requirements of the body, without a waste of food nutrients, 

 constitutes scientific feeding. 



Analysis of Feed Stuffs 



A complete analysis of feed stuffs gives in percentages the 

 contents of water, ash, protein, nitrogen, free extracts (mainly 

 carbohydrates), and fats. 



Water 



Water, or moisture, is more or less contained in all feed stuffs, 

 but being more than ordinary water, it has no special nutritive 

 value. The more water a feed stuff contains, however, the less 

 of the other nutritives it contains, and the more liable it is to 

 injury by heating, souring, or molding. The water contents 

 of feeds vary. In grains and other concentrates it runs from 

 about 7 per cent to 12 per cent but larger in fresh grains. 



Nutritive Ratio 



The nutritive ratio is the proportion of digestible protein to 

 digestible non-protein, but, as heretofore stated, I shall not enter 

 into the digestibility of feeds, except to a very limited extent, 

 for fear of making the subject appear too intricate and difficult 

 of understanding, and confusing to the reader. In calculating 

 the digestibility of feeds, as practically all pigeon feeds have 

 about the same proportion of digestibility, I shall give only the 

 total content of each element, as shovm by chemical analysis. 



In calculating the nutritive ratio, the percentage of fats (either 

 extract), is multiplied by 214, and to this product is added the 

 sum of the percentages of nitrogen-free-extract (hereinafter 

 called carbohydrates), and crude fiber, and this total is divided 

 by the percentage of protein, which gives the nutritive ratio. 



