70 UNIVERSITY OF WISCONSIN STUDIES 



of the experiments show a decline in the saponification value 

 and Reichert-Meissl number of the butter fat, and an increase 

 in the iodin-absorptioii value. The melting point, however, 

 in some cases was increased, in some cases was not affected, 

 and in other cases declined. Another striking feature of 

 the results is the extreme variations in the chemical fat con- 

 stants obtained in a great many of the experiments. In 

 fifteen of the twenty-three experiments given in the tables 

 the maximum iodin-absorption value rose to a figure of 40.0 

 or above and in twenty-one of the twenty-three experiments 

 to a figure of 36.0 or above. The extent of these variations is 

 emphasized when they are compared with the average normal 

 iodin value of 32.7 for all the experiments. Similarly, 

 Reichert-Meissl numbers below 24.0, the legal standard for 

 butter in the United States, were obtained in ten of the twen- 

 ty-three experiments. Reichert-Meissl numbers below 28.0, the 

 Belgian legal standard for butter, were obtained in twenty 

 of the twenty-three experiments. Again, the extent of these 

 variations is emphasized by comparison with the average 

 normal value of 29.1 for the twenty-three experiments. 



Application of the results of underfeeding studies. The 

 marked variations in the chemical and physical constants 

 of the milk fat which are found to accompany a subnormal 

 plane of nutrition, even in cases of mild underfeeding, or 

 when the plane of nutrition is merely reduced from super- 

 normal to normal, at once indicate the importance of taking 

 into account this important factor in both human nutrition 

 and in experimental work involving the influence of specific 

 factors on the composition of milk fat. 



It is certain that at times milk comes to the market from 

 herds in such a condition of underfeeding that the fat will 

 have the somewhat abnormal composition noted in the experi- 

 mental work reported. It is of interest in this connection 

 to raise the question as to the possible relation between the 

 character of the fat and human nutrition, especially of infants. 

 Unfortunately up to the present 110 information is at hand 

 concerning this possible relation although it seems entirely 

 possible it may be a matter of some importance. The im- 



