104 THE CHEMISTRY OF THE FARM. 



probably due to the different breeds of animals experi- 

 mented with. The influence both of breed, and of the 

 individual character of the animal on the rate of increase 

 whilst fattening is very considerable. 



The results relating to manure will be discussed in the 

 next chapter. 



We have hitherto looked at the fattening period as a 

 whole ; the rates of consumption and of increase are, 

 however, very different in different stages of this period. 



As a fattening animal increases in size the quantity of 

 food it consumes also somewhat increases, the require- 

 ments of the body for heat and renovation of tissue 

 becoming greater as its weight and size are increased ; the 

 stomach at the same time becomes larger. When the animal 

 becomes very fat, the consumption of food falls off again, 

 the rate of increase at this point being much diminished. 



As fattening advances the daily increase in live weight 

 becomes gradually smaller, and the same amount of food 

 will i^roduce a steadily diminishing amount of increase. 

 This is partly because the increase during the later stages 

 of fattening is drier, and contains a larger proportion of 

 fat than in the earlier stages of the process. Partly also 

 because the consumption of food for heat and work is 

 increased with the increasing size of the body. More 

 internal work must also be performed to add increase to a 

 large animal than to a small one. These changes in the 

 rates of consumption and increase are seen more strikingly 

 in the case of pigs than with other animals, from the 

 greater rapidity of the fattening process. The following 

 table shows the average results obtained on sixteen pigs 

 fattened at Rothamsted at the same time, the food being 

 7 lb. of pea meal per head per week, with an unlimited 



