FEEDING DAIRY CATTLE 229 
The fat is the most valuable single component of the milk; it 
determines the quality and value of the milk as a human food, and 
largely, also, as a raw material for the manufacture of dairy prod- 
ucts. A high fat content is, as a tule, accompanied by a high 
per cent of solids other than fat, and is, therefore, of direct value 
in the manufacture of butter, cream, and ‘condensed milk, and, up to 
a certain extent, in cheese-making as well. 
Factors Influencing Milk Production—The main factors that 
influence the amount and quality of milk produced by cows are: 
Breed, individuality, age, stage of lactation period, frequency of 
milking, condition, excitement, season of the year, temperature 
and weather, grooming, and amount and character of feed. 
Breed.—The various breeds of cows yield milk in different 
amounts and of different quality, as is well known to all. The fol- 
lowing compilation, giving the average production of milk and 
butter fat by pure-bred dairy cows, will show the extent of the 
differences between the various breeds in these respects. The figures 
were compiled from the results obtained in tests conducted for a 
series of years at four American experiment stations (Maine, New 
Jersey, New York, and Wisconsin). The cost of feed required to 
produce 100 pounds of milk and 1 pound of butter fat in the case 
of the different breeds.is also given. Prices of feed have advanced 
from 30 to 40 per cent since these breed tests were conducted, 
hence the figures in the last columns should be varied accordingly.* 
Test of Pure-bred Dairy Cows—Average Results for Four Stations 
Average yield per 
lactation period, Feed cost for 
Breed 4 aba Lacta- pounds eet, 
Tee er 0: tion cen 
cows | periods 7 fat oan A aoe 4 
BMilc: i], ae milk, |” fat, 
cents cents 
DOTSEY ciao is widtcncgdds eee 19 87 | 5681 302.1 5.32 77.6 15.2 
Guernsey............ 17 67 6243 317.1 5.08 69.9 13.7 
Holstein............. 14 43 | 9275 317.7 3.42 61.3 17.9 
Ayrshire............. 10 20 6909 248.5 3.59 78.5 21.5 
Shorthorn.......... fe 12 55 7512 296.5 3.94 62.4 15.3 
DEVO ee cesorwink ae» 3 5 3984 183.3 4.60 94.0 20.5 
Brown Swiss......... 2 6 6971 273.0 3.91 49.5 12.6 
American Holderness.. 2 ‘4 5721 213.1 3.73 76.0 20.1 
Total and average. 79 287 eae (are age 71.2 17,1 
Only a limited number of cows of the various breeds were in- 
cluded in these tests, and the conditions under which the tests were 
® See also Wisconsin Report, 1901, p. 85. 
