Farm engineering is concerned with layouts, and the projection of physical enterprises on the land, — as surveying, laying out drains, irrigation works, roads, bridges, and the like. Farm mechanics has to do with construction, and the principles of physics underlying it. Farm machinery as a department of knowledge has to do with the application of mechanics to those devices known as machines. Farm architecture is concerned with the building of barns, residences, and other housing structures.

Silos

Least number of dairy cows that should be fed from silos of given diameters

(Rawl and Conover)

Feeding capacity of silos (Wis: Sta.).

When the cows are getting 40 pounds of silage daily, each cow should be allowed 4 to 5 square feet of feeding surface in the silo. Ten cows would require a feeding surface of 50 feet. A silo 8 feet in diameter would have a cross section, or feeding surface, of 50 square feet. For 10 cows, therefore, a silo should be 8 feet in diameter. Fifteen cows should have a silo 10 feet in diameter ; 20 cows should have a silo 12 feet in diameter. The diameter of silos required for different numbers of cows is shown in the following table. It is assumed that each cow eats 40 pounds of silage daily.

Diameter of Silo (in feet)

Number of Cows to be Fed

10....................

12

12....................

17

14....................

23

16....................

30

18....................

38

Feed for 180 days

 

Silo 30 Ft. Deep, 24 Ft. of Silage

Silo 36 Ft. Deep, 30 Ft. of Silage

Number of Cows in Herd

Fed down at rate 1 1/2 in. daily

Fed down at rate of 2 in. daily

Tons Silage

Inside Diameter

Tons Silage

Inside Diameter

14......

36

10

36

9

15......

54

13

54

11

20......

72

15

72

12

25......

90

16

90

14

30......

108

18

108

15

35......

126

19

126

16

40......

144

21

144

18

45......

162

22

162

19

52......

180

23

180

20

60......

216

25

216

21

70......

252

27

252

23

80......

288

29

288

25

90......

324

31

324

26

100......

360

33

360

28

Approximate quantity of silage required per day (III. Sta.)

Kind of Stock

Daily Ration

Beef Cattle—

Pounds

Wintering calves, 8 months old...............

15 to 25

Wintering breeding cows..............

30 to 50

Fattening beef cattle 18-22 months old —

 

First stage of fattening........

20 to 30

Later stage of fattening........

12 to 20

Dairy cattle..................

30 to 50

Sheep —

 

Winering breeding sheep.............

3 to 5

Fattening lambs...........

2 to 3

Fattening sheep.............

3 to 4

This table, in connection with the following, may be used to determine the size of silo needed to fulfill various conditions. For example, if the silage is to be fed to a herd of 40 dairy cattle at the rate of 40 pounds per head per day, a silo 16 or 18 feet in diameter will be satisfactory.

Capacity of silo (King)

Chapter XXV Construction Farm Engineering Mechanic 176

Necessary diameter of silos for feeding different numbers of cows while removing from 2 to 3.2 inches of silage daily (King)

Each cow is allowed 40 pounds of silage daily ; silo3 to be of sufficient capacity to hold silage for 180 days.

 

Silo 30 Ft. deep, no Partition Mean Depth fed Daily, 2 In.

Silo 24 Ft. deep with Partition Mean Depth fed Daily, 3.2 In.

No. of Cows

Contents

Round diameter in ft.

Square sides in ft.

Contents

Round diameter in ft.

Square sides in ft.

Tons

Cu. Ft.

Tons

Ct. Ft.

30 ... .

108

4,091

15.0

12 X 14

108

5,510

17.00

16 X 16

40 ... .

144

6,545

16.75

14 X 16

144

7,347

20.00

18 X 18

50 ... .

180

8,182

18.75

16 X 18

180

9,184

22.00

20 X 20

60 ... .

216

9,818

20.50

18 X 18

216

11,020

24.00

22 X 22

70 ... .

252

11,454

22.00

20 X 20

252

12,857

26.00

22 X 26

90 ... .

324

14,727

25.00

22 X 24

324

16,531

29.75

26 X 28

100 ... .

360

16,364

26.50

24 X 24

360

18,367

31.25

28 X 28

Other silo figures.

Silos are now preferably cylindrical, for the silage packs and settles more evenly than in square or cornered constructions. Most silos now are wooden tank-like structures built of upright wooden staves. In the northernmost dairy regions, the silo may be inside the barn; but usually it is outside the main barn structure.

Weight of silage in silos of different depths two days after filling the silo

(King)

Depth of Silage

Weight at Different Depths

Mean Weight of Silage for Whole Depth of Silo

Feet

Lb. per cu. ft.

Lb. per cu. ft.

1........

18.7

18.7

5........

25.4

22.1

10........

33.1

26.1

15........

40.0

29.8

20........

46.2

33.3

25........

51.7

36.5

30........

56.4

39.6

35........

61.0

42.8