60 Feeds and Feeding. 



above the amount due to the basal ration. Kellner maintains that 

 this additional deposit was derived from the protein fed in the 

 wheat gluten. Less body fat was formed by the steers from 100 

 lbs. of protein than would have been formed by dogs, on account of 

 the large losses which occur thru fermentations in the digestive 

 organs of ruminants. As above shown, Kellner found that because 

 of the large losses which occur thru fermentations in the digestive 

 organs of herbivora, only 23.5 lbs. of fat can be formed by these 

 animals from 100 lbs, of protein in the food. 



84. The source of fat in milk. — By an ingenious experiment Jor- 

 dan and Jenter of the New York (Geneva) Station^ proved that the 

 cow can form the fat of milk from substances other than the fat in 

 her food. A thousand lbs. of hay and 1500 lbs. each of corn meal 

 and ground oats were sent to a new-process oil-meal factory, where 

 nearly all the fat was extracted from these feeds with naphtha in 

 the percolators employed for extracting the oil from crushed flax 

 seed. The almost fat-free feeds were returned to the Station and 

 afterwards fed to a cow which had freshened about 4 months be- 

 fore. For 95 days the cow lived on these nearly fat-free feeds, 

 yet during this period she gave 62.9 lbs. of fat in her milk. The 

 food she consumed contained but 11.6 lbs. of fat, of which only 5.7 

 lbs. was digested. Hence at least 57.2 lbs. of the fat found in the 

 milk must have been derived from some other source than the fat 

 in the food. This fat could not have come from the body of the 

 cow, for Jordan writes: "The cow's body could have contained 

 scarcely more than 60 lbs. of fat at the beginning of the experi- 

 ment; she gained 47 lbs. in weight during this period with no in- 

 crease of body nitrogen, and was judged to be a much fatter cow 

 at the end; the formation of this quantity of milk fat from the 

 body fat would have caused a marked condition of emaciation, 

 which, because of an increase in the body weight, would have re- 

 quired the improbable increase in the body of 104 lbs. of water and 

 intestinal contents." 



Jordan concludes that not over 17 lbs. of the fat produced during 

 the trial could possibly have been produced from the protein sup- 

 plied in the food. It is most evident that a large part of all the 

 fat produced by this cow must have come from the carbohydrates 

 in her feed, and so a long disputed question is at length settled. 



^ Bui. 132. 



