2 BULLETIN 972, U. S. DEPARTMENT OE AGRICULTURE. 
In September, 1919, the work was resumed and records were obtained 
for the second year. Thus there was an interval of one year between 
the two years in which the studies were made. 
Although the figures obtained show what was required to produce 
milk for the Omaha market under the system of dairy management 
found in the section studied, and probably approximate the require- 
ments in similar sections, they, of course, do not apply to dairying 
in sections where different conditions and methods of management 
prevail. 
METHODS OF OBTAINING DATA. 
The figures reported are based on actual records obtained by 
regular monthly visits of 24 hours each to 8 farms for two entire 
years and to 22 other farms for one entire year. 
At the beginning and end of each year the field agent took an 
inventory of the dairy buildings, livestock, and equipment used in 
the care of the herd and its products. On his regular monthly visit 
at each farm the field agent, with watch in hand, noted and recorded 
the exact minute each labor operation on the dairy was begun and 
ended. An equally careful record was obtained of the kind, quantity, 
cost, and description of each feed fed. The quantity of milk sold 
and receipts each month were obtained. In addition the milk used 
by the proprietor and his help or fed to calves was measured or 
weighed on the monthly visit and used as a basis for determining 
the quantity kept on the farm during the month. 
The dairymen kept itemized accounts of expenses incurred between 
monthly visits and reported these items to the field agent. Monthly 
records were kept of the purchase or sale of cows, calves, hides, the 
cost of outside bull service, and other miscellaneous information. 
Accurate records of calves born and first-hand information on the 
condition and methods of handling manure were collected system- 
atically. 
The records of all the herds for each month made it possible to 
obtain representative data for each month, season, and year. Rec- 
ords were obtained the second year as a check on the first year's 
work and to increase the quantity of data for study. 
INFLUENCE OF SEASONS ON COST FACTORS. 
The results have been reported separately for the winter and 
summer seasons because the season of the year may have a marked 
influence on the principal factors of cost. The months from Novem- 
ber to April, inclusive, are considered as the winter season and the 
months from May to October, inclusive, as the summer season. 
The various tables are based upon figures obtained during the 
two-year study, and the weighted averages of these records were 
