FOOD 289 



likely to contain a sufficiency of all the essential inorganic 

 elements except sodium, which is usually added in the form 

 of sodium chloride. Calcium and phosphorus are of special 

 importance in the feeding of dairy cows and growing animals. 

 In the former there is a loss of these elements in the milk, and 

 in the latter they are required for growth of bone. Calcium 

 is abundant in leguminous hays and in animal products, such 

 as meat meal. It is present only in small quantities in grains. 

 Maize is especially deficient in this element. Phosphorus, as 

 phosphates and phospholipins, e.g. lecithin (p. 19), is present 

 in relatively large amounts in feeding stuffs that are rich in 

 proteins, such as animal products and leguminous seeds. It 

 is also abundant in bran, middlings, and oil seeds. Roots and 

 straws are deficient. Potassium is abundant in fodders where 

 it is sometimes present in excessive amounts (p, 280). 



The total amount of ash of feeding stuffs is determined 

 by incinerating a weighed example, and weighing the residue. 



5. Water. 



The amount of water present in feeding stuffs is very 

 variable, in different foods, and in the same material at different 

 stages of growth. The following table gives a rough idea of 

 the water content of some common feeding stuffs : — 



Water per cent. 



Roots and tubers .... 80-90 



Green fodder 



Hay and Straw . 



Grain 



Feedin" cakes and meals 



65-80 

 7-15 

 10-12 

 under 10 



As the water yields no energy the percentage present 

 dilutes the nutrition value. Fermentation and the growth of 

 moulds are liable to occur when the water content exceeds 

 17 or 18 per cent. 



The percentage of water is estimated by determining 

 the loss of weight on drying a sample at a temperature 

 of 100° C. 



6. Accessory Factors. 



These have been dealt with (p. 281). 

 19 



