92 



Scientific Proceedings (64). 



55 (987) 



The influence of beef fat on growth. 



By Thomas B. Osborne and Lafayette B. Mendel. 



[From The Laboratory of the Connecticut Agricultural Experiment 

 Station and the Sheffield Laboratory of Physiological Chemistry 

 in Yale University, New Haven, Connecticut.] 



The inability of young albino rats to complete their growth on 

 a diet consisting of isolated proteins, starch, "protein-free milk" 

 and lard has directed attention to the need of some substance to 

 supplement the ordinary nutrients so that the characteristic 

 increment in body weight may proceed to its normal limits. 1 

 Among naturally occurring fats, butter fat, egg yolk fat, and cod 

 liver oil have been shown to be effective as adjuvants to the above 

 artificial dietary in order to promote growth; whereas lard, almond 

 oil, and olive oil behave otherwise. We have now found that beef 

 fat is likewise capable of promoting renewal of growth when it 

 has been checked on the lard diets; or if beef fat is incorporated 

 with the food at an early period there is no cessation of growth 

 until long after the time at which nutritive failures on the inade- 

 quate diets usually occur. 



The content of the growth-promoting substance appears to be 

 smaller in beef fat than in butter fat. By fractional separations 

 it can be obtained in the more liquid portions of the fat — the 

 "beef oil." Beef oil and beef fat, like butter fat and cod liver oil, 

 seem to exert a curative effect in certain affections of the eyes 

 which the rats experience as the result of malnutrition. 



A more detailed account of the work will appear in the Journal 

 of Biological Chemistry. 



1 Cf. Osborne and Mendel, Journal of Biological Chemistry, XV, p. 311, 1913; 

 XVI, p. 423, 1913; XVII, p. 401, 1914; McCollum and Davis, XV, p. 167, 1913; 

 XIX, p. 245, 1914. 



