17<i Meat Froduction 



Rothamsted investigation, m = 1131, iM = 133i,/- 20-81, F = 32-02, 

 the total amount of digestible nutrients required to produce the increase 

 (2031b.) would be about 800 lb. ; and if the duration of the fattening 

 period were 100 days the average amount would be 8 lb. — say TJ lb. 

 of starch and | lb. of protein — per day in excess of maintenance require- 

 ments. 



There is at present no known method by which the percentage of 

 fat in the bodies of living animals can be exactly determined ; and until 

 such is forthcoming it can only be inferred from the "condition" as 

 estimated by practical experts. This is admittedly crude and unsatis- 

 factory but it was considered good enough for the estimation of the 

 composition of "fattening increase" by Lawes and Gilbert and it is, in 

 effect, for that jiurpose it is now required. They established the following 

 relations: 



It appears therefore tliat the verbal terms used by practical experts 

 to describe condition may be interpreted approximately as follows: 



The value of // is tolerably well known. Kellner^ found that ruminants 

 produce from 474 to 598 grams of body fat from 1 kg. of digestible fat 



'^ Bull. 28, U.S. Dept. of Agric., "Chemical composition of American Food Materials." 

 - Scientific Feeding of Animals, p. 82. 



