PRODUCING MARKET MILK IN NORTHWESTERN INDIANA. 23 
and the difference between this, plus the receipts for the outgoing 
animals and hides sold, and the first inventory, plus the value of in- 
coming animals at the time they entered the herd during the year, 
constituted the depreciation or appreciation on the herd for the year. 
As in the case of feed and labor the records on the cows and bulls were 
kept separate for each herd in order that the requirements for pro- 
ducing a certain quantity of milk, aside from the cost of keeping 
bulls, would be available for study.' Kecords were obtained of the 
actual costs of taxes, insurance, veterinary services, medicine, dis- 
infectants, and cow-testing dues. 
BUILDINGS. 
The buildings, including silos, were inventoried at the beginning 
and the end of the year and interest at 5 per cent was figured on the 
value of those used for the cows, as shown by the first inventory. 
The first inventory value, divided by the years it was estimated the 
buildings would remain in a usable condition, constituted the de- 
preciation charge. The cost of painting, shingling, and repairs was 
computed, and wherever possible the exact cost was obtained and 
recorded under "Upkeep and repairs." The dairies were charged 
with their share of the actual taxes and insurance paid, as shown by 
county records and insurance policies. 
EQUIPMENT. 
The dairy equipment was inventoried at the beginning and the 
end of the year. Interest at 6 per cent was charged on the first 
inventory value. The difference between the first inventory, plus 
equipment purchased, and the one taken at the end of the year, 
plus equipment sold, was recorded as depreciation. A list of all 
repairs on equipment and dairy supplies purchased was kept by the 
dairymen and recorded each month. The taxes on equipment, as 
for cattle and buildings, were taken from the county records. 
CREDIT FOR MANURE. 
In the computation of credit to be allowed for winter manure, six 
factors were considered, namely, the fertilizing constituents con- 
tained in the feed consumed; the proportion of nitrogen, phosphoric 
acid, and potash not utilized in the bodies of the cows but voided in 
the manure; the per cent of the total manure which was voided in 
the barn; the per cent saved in handling and storing; the nitrogen, 
phosphoric acid, and potash in the bedding; and the value of these 
constituents in the manure and bedding at wholesale prices for com- 
mercial fertilizers. 
The small quantity of manure saved in the barn in the summer 
was presumed to be of the same quality as that produced in winter, 
