72 UNIVERSITY OF WISCONSIN STUDIES 
days at least is apparent when it is considered that she sud- 
denly was required to gather by her own activity about 
seventy pounds of pasture grass to supply the eight therms of 
energy which she required. Even this figure may be too low, 
for it is based on the energy value of green alfalfa, which 
is in all probability higher than that of the fresh blue grass 
pasture to which the animal was turned and for which no 
data are available. The underfeeding results, which were 
temporary, are seen in the marked drop in the saponification 
and Reichert-Meissl values of the milk fat, and in the great 
increase in the iodin value. The fact that underfeeding 
accompanied a change to pasture in the case of this cow 
with a low milk production emphasizes the danger as well as 
the probability of a similar but more pronounced result 
accompanying the turning to pasture of cows with much 
greater milk production. 
TABLE VII 
CHANGING THE RATION FROM DRY FEED T0 FRESH PASTURE, SHOWING 
THE EFFECT OF UNDERFEEDING * 
Milk Fat in Saponi- Reichert- Iodin Melting 
yield Date milk fication Meissl value point 
value number 
Pounds Per cent °C. 
18.8 May 18-19 4.55 224.0 25.92 37.02 32.83 
4.5 May 20 a. m. 4.35 225.7 24.05 39.11 33.40 
4.8 May 21 a. m. 4.47 221.1 23.99 42.68 32.10 
4.0 May 21 p. m. 5.76 219.5 22.69 45.34 31.40 
5.0 May 22 a. m. 4.04 223.2 “25.10 38.28 33.37 
5.7 May 22 p. m. 5.29 223.6 24.68 41.67 32.67 
9.8 May 23 5.00 223.6 25.87 43.19 31.87 
19.6 May 24-25 4.92 223.7 27.15 42.15 32.27 
* Fed on May 18-19, 4.5 pounds of grain, 4.5 pounds of alfalfa hay, and 18 
pounds of silage. The other data are based on pasture only. 
Equally striking results were obtained in several other 
experiments when the ration was grain and dry roughage. 
In all these cases the striking change in the properties of the 
fat might have been attributed to the change in ration while 
the real cause was an insufficient amount of nutrients. 
