Laboratory Exercises “363 
will only be approximate, as the weight of silage varies with the 
depth below the surface, with the amount of water in silage, and 
with the diameter of the silo. 
19. Scorinc THe Dairy Cow 
Object. To compare good and poor dairy cows. 
Materials. A good and a poor dairy cow; a score-card. 
Directions. With the score-card in hand very carefully go over 
the animals and compare each point mentioned on the card. 
Note the udders especially, page 132. 
20. Mxasurine Dairy Cows 
Object. To see if there is any relation between form and func- 
tion in dairy cows. : 
Materials. A dairy herd. Measure as in Exercise 3. 
Directions. Cows of a triple-wedge form are more desirable. 
To possess this form they must be much larger around the body 
just back of the hips and in front of the udder, than they are around 
the heart. Measure several good producing cows, and several 
poor producing. Average the front measurements of the good 
producers; then the hind measurements; do likewise for the poor 
producing. Is there a greater difference between the fore and hind 
measurements in the good cows than between the fore and hind 
measurements of the poor cows? Take measurements suggested 
on page 133. 
21. Formine Ration ror Dairy Cow 
Object. To learn to form ration for a dairy cow with given foods 
at stated prices. 
Materials. None. 
Directions. Form aration for a 1000-pound dairy cow, yielding 
15 pounds of milk per day, using any of the foods in Exercise 14. 
The ration should contain 24 pounds of dry matter with a nutritive 
