74 UNIVERSITY OF WISCONSIN STUDIES 



to eight pounds of potato pulp and three-fourths to one pound 

 of rice polishings a head daily. The explanation of the ab- 

 normally low saponification and Reichert-Meissl values un- 

 questionably lies in this fact. The conclusion that would 

 naturally be drawn in the light of the studies of the influence 

 of underfeeding is that the animals were underfed on account 

 of the short pasture. 



Ziegfeld 10 reported a sudden drop in the Reichert-Meissl 

 value of the butter fat during a period of feeding cows on 

 beet-tops, which is attributed to a sudden fall in the tempera- 

 ture, causing the leaves to become to some extent frozen. 

 Inasmuch as the cows were fed the beet-tops ad libitum with 

 no additional feed, it would hardly be expected that they 

 would consume the required amount to support maintenance 

 and milk flow if they were suddenly required to eat the partly 

 frozen beets. A number of other equally clear cases have 

 been gathered from the literature. 



CONCLUSIONS 



The percentage of fat in milk can be influenced to a marked 

 extent for the first twenty to thirty days by the fatness of the 

 animal at parturition. This influence appears to extend in 

 some cases in a less degree for at least three months. 



Underfeeding of the animal after parturition seems to be 

 a necessary condition to bring about this abnormal percentage 

 of fat in the milk. 



Tests of dairy cows made for short intervals in the be- 

 ginning of the lactation period cannot be depended upon to 

 indicate the normal percentage of fat produced by the cows 

 tested. 



Underfeeding of the lactating cow results in a decline in 

 the Reichert-Meissl number and the saponification value and 

 an increase in the iodin value of the milk fat. 



The increase in the percentage of milk fat and the changes 

 in the character of the fat which accompany underfeeding 



10 M. Ziegfleld, Die Zusammensetzung des Butterfettes bei Riibenblatt- 

 filtterung in Z. Nalir. Genussm., 17, 179-86, 1909. 



