460 



EVENING DISCOURSES 



He obtains protective foods — vitamins and minerals — in small quantities 

 from almost all the foods he eats. But of all foods, leaves are the form of 

 food which contain most, if not all, of the vitamins, and leaves are rich in 

 minerals ; though the actual concentration of certain vitamins is greater in 

 some kinds of meat, such as liver, or in certain parts of the grain. 



The following diagram shows the derivation of the principal types of 

 human food from leaf matter : 



LEAF MATTER 



FRUIT 



6RAIN 



-«■ 



ANIMALS 



MEAT 



MILK 

 CHEESE 

 BUTTER 



Fig. I. 



Farm animals — cattle, sheep and pigs — eat grass in the leafy stage, and 

 hay, cereals and feeding cakes. The latter are tropical seeds and nuts from 

 which the oils have been extracted for making soap or margarine. 



There is not much doubt that for cattle and sheep grass is the best food 

 when it is available — but the pig thrives best on grain as well, since he has 

 not a stomach large enough to deal with all his food in a bulky fibrous form. 



Our system of feeding a farm animal may be illustrated by reference to 

 a milch cow. From early May it grazes the pastures, eating the leaves of 

 grasses and clovers, from which it can obtain all the nourishment it requires, 

 even when it is producing up to 4 gallons of milk a day. Later, in the 

 summer, when the grass has become more stemmy with less leaf, a heavy 

 milking cow finds it more difficult to obtain all the food it requires, especially 

 if the soil is becoming dry and new leaves of grass are not growing. It is 

 then usual to supplement the grass grazed by the cow with a ration of feeding 

 cakes. 



From the autumn rains there is generally another flush of leafy grass, 

 and again the heavy yielding cow can obtain nearly all it requires from the 

 pasture. Then, in the late autumn, the cow is usually housed for the winter 

 and fed on hay, roots and feeding cakes, cereals and other meals, until 

 spring returns. 



Actually the cow which is giving milk is only fed entirely on grass for 

 quite a short time of the year — perhaps May, part of June, and then again 

 from the middle of August to the middle of September. 



