44 SCIENCE AND PRACTICE OF DAIRYING. 



a double reward, due to an increased yield of milk, along with an 

 increased percentage of fat. 



The supplying of nourishment of a suitable kind and quality should 

 not be left to the promptings of nature or the caprice of the animal, but 

 should be regulated by regular laws, and varied according to the live 

 weight. For this reason, it has been agreed to regard as the standard of 

 comparison for the measurement of the food requirements of domestic 

 .animals the weight of 1000 Ibs. (in England and America), or 500 kilos 

 {in Germany). 1 Cows' milk, which is the natural food of young calves, 

 contains, as its nutrient ingredients, water, nitrogenous matter (protein), 

 fat, a carbohydrate, and mineral substances. These nutrients are the same 

 as those on which the cow must be fed throughout her whole life, and 

 which must be daily supplied in digestible forms and in definite quantities. 

 An average cow requires, according to the commonly accepted standards, 

 the following amounts per 1000 Ibs. of live weight: 



Dry substance in food, 15 to 35 Ibs.; average, 25 Ibs. 



Containing digestible protein, 2*25 to 2 -75; average, 2*50 Ibs. 

 ,, fat, *4 to *6; average, *5 Ibs. 



carbohydrates, 10 to 15; average, 12-5 Ibs. 



,, dry substance in the form of coarse fodder 12 to 20; 



average, 16 Ibs. 

 salt (in addition), 10 to 70; average, 40 grams. 



Cattle require daily, on an average, about three times more water than 

 dry substance. With regard to mineral matters, it may be assumed that 

 these will be found in sufficient quantity in the daily food, if this be supplied 

 in sufficiency and of a suitable character. 



The utility of a food depends on the ratio of the amount of nitrogenous 

 nutrients to the amount of fat and the other non-nitrogenous nutrients. 

 None of the different nutrients effects a definite physiological action, but 

 -each one has a particular function to perform in the animal system. The 

 nitrogenous matter of food has been named "flesh-forming", since its chief 

 function is to build up and renew the tissue of the animal body; while the 

 non- nitrogenous nutrients have been called "heat-giving", since they 

 chiefly effect the maintenance of heat in the system. As the nitrogenous 

 substance is indispensable for the formation and repair of the animal 

 tissue, and as this can be effected by no other group of nutrients, it 

 follows that the value of a feeding ration is, above all, dependent on its 

 percentage of protein matter. The ratio between the quantity of digestible 

 nitrogenous matter, and the quantity of digestible non-nitrogenous consti- 

 tuents, in a ration, is expressed by a fraction whose numerator is 1. This 



1 500 kilos = 1100 Ibs. 



