MAINTENANCE: RATION AND FATTENINGS 



441 



were then killed and subjected to analysis. A quantity of fat 

 equal to that in the pig first killed was subtracted, and the differ- 

 ence assumed to represent the gain in fat. The results of the 

 experiment are as follows : 



Thus, after allowing for the greatest possible gain of fat from 

 the proteids and the fat fed, there remains a large quantity of fat 

 which could come only from the carbohydrates. 1 



The fat of the animal has been found to be modified by the fat 

 of the food to a certain degree. In one experiment, a fat con- 

 taining iodine was fed, and was found in the body fat, and also 

 passed into the milk. A portion of the fat of the food may be 

 stored in the animal. The body fat of each kind of animal 

 possesses characteristic properties ; the cow produces only cow 

 fat; the dog, dog fat, etc. Under ordinary conditions, only a 

 small part of the animal fat comes directly from the food ; the 

 major portion is a product of the transformation of matter in 

 the cells of the animal. Only when foods rich in fat, such as oil 

 cake, corn, rice bran, etc., are fed, can the characteristics of the 

 food fat be observed in the fat of the body or of the milk. It is 

 usually the custom to finish the animal on feed which will give 

 the desired characteristics. The fat of animals fed on cereals 

 and grains rich in carbohydrates and poor in oils, is hard. A 

 softer fat is obtained when linseed cake, peas, wheat bran, oats, 

 etc., are fed. Animals exposed to cold have a softer fat than 

 1 See also Bulletin 22, p. 271, Office Exp. Sta., U. S. Dept. Agr. 

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