Weights and Measures of Common Feed

AS-1282 JUNE 2005

Table of Contents

Table 2

Granular Material

Application

Compiled by

J. W. Schroeder

Dairy Specialist
NDSU Extension Service

Contributions from

Kenneth J. Hellevang

Agricultural Engineer
NDSU Extension Service

In calculating rations and mixing concentrates, using weights rather than measures usually is necessary. However, in practical feeding operations, measuring the concentrates often is more convenient for the farmer or rancher.

■ FORAGE

Storage Space Requirements for Feed and Bedding

The space requirements for feed storage for the livestock enterprise - whether it is for cattle, sheep, hogs or horses, or as is more frequently the case, a combination of these _ vary so widely that providing a suggested method of calculating space requirements applicable to such diverse conditions is difficult. The amount of feed to be stored depends primarily upon (1) length of pasture season, (2) method of feeding and management, (3) kind of feed, (4) climate, and (5) the proportion of feeds produced on the farm or ranch in comparison with those purchased.

Normally, the storage capacity should be sufficient to handle all feed grain and silage grown on the farm and to hold purchased supplies. Forage and bedding may or may not be stored under cover.

In those areas where weather conditions permit, hay and straw frequently are stacked in the fields or near the barns in loose, baled or chopped form. Sometimes sheds or a waterproof cover is used for protection. Other forms of storage include temporary upright silos, trench silos, temporary grain bins and open-wall buildings for hay.

Hay Weight in a Stack or Barn

Stockmen and hay dealers frequently buy and sell large quantities of hay in the stack or in the barn. This practice is prevalent especially in the Western and Great Plains states, where cattle and sheep are brought into the farm yard to be wintered on hay bought from hay producers.

Under such circumstances, the weight of hay usually is estimated because (1) no scales are available, and/or (2) weighing the hay is impractical due to the time, labor and wastage involved. In many such instances, the hay is fed directly from the stack or barn, in racks arranged about it. Under these and other circumstances, there is need for a simple and reasonably accurate method of estimating the weight of hay in a stack or barn.

To estimate the tonnage of hay in a stack or in a barn, you need to (1) compute the volume of hay, and (2) know the number of cubic feet per ton of hay. Table 1 gives the density information.

Table 1.Storage space requirements for feed and bedding.¹

Kind of Feed or Bedding Pounds per Cubic Foot Cubic Feet per Ton Pounds per Bushel of Grain

Hay

     1. Loose

          Alfalfa 4.0-4.4 450-500 �

          Nonlegume 3.3-4.4 450-600 �

          Straw 2.0-3.0 670-1,000 �

     2 Baled

          Alfalfa 6.0-10.0 200-330 �

          Nonlegume 6.0-8.0 250-330 �

          Straw 4.0-5.0 400-500 �

     3 Chopped

          Alfalfa, 1�-inch cut 5.5-7.0 285-360 �

          Nonlegume, 3-inch cut 5.0-6.7 300-400 �

          Straw 5.7-8.0 250-350 �

Corn

     15�% moisture:

          Shelled 44.8 � 56

          Ear 28 � 70

          Shelled, ground 38 � 48

          Ear, ground 36 � 45

     30% moisture:

          Shelled 54 � 67.5

          Ear, ground 35.8 � 89.6

Barley, 15% moisture 38.4 � 48

          Ground 28 � 37

Flax, 11% moisture 44.8 � 56

Oats, 16% moisture 25.6 � 32

          Ground 18 � 23

Rye, 16% moisture 44.8 � 56

          Ground 38 � 48

Sorghum grain, 15% moisture 44.8 � 56

Soybeans, 14% moisture 46 � 60

Wheat, 14% moisture 48 � 60

          Ground 43 � 50

¹Source: Adapted from Beef Housing and Equipment Handbook, Midwest Plan
Service, Iowa State University, 4th edition, 1987, Table 8-13, pg. 8.21 and
Table 8-17, pg. 8.22.

In using Table 1, you must recognize that many factors — other than kind of hay, form (loose, chopped, or baled) and period of settling — affect the density of hay in a stack or in a barn, including (1) moisture content at haying time, and (2) texture and foreign material.

Computing the volume of hay in a mow is relatively simple, but determining the volume of a stack is more difficult. Although different rules or formulas may be and are used, the U.S. Department of Agriculture¹ recommends the following:

1. Volume of hay in barns
Multiply the width by the length by the height, all in feet, and divide by the cubic feet per ton as given in Table 1.

2. Volume of hay in oblong and rectangular stacks
Three types of oblong stacks are common, as shown in Figure 1 (page 3). The volume of each type of oblong stack may be determined as follows:

a. For low, round-topped stacks: (0.52 x O) - (0.44 x W) x W x L

b. For high, round-topped stacks: (0.52 x O) - (0.46 x W) x W x L

c. For square, flat-topped stacks: (0.56 x O) - (0.55 x W) x W x L

In these formulas, O is the "over" or "over-throw," which is the distance in feet from the ground on one side of the stack, up and over the stack and down to the ground on the other side; W is the width; and L is the length.

The application of this formula is illustrated as follows:

Example. You want to estimate the amount of alfalfa hay in a low, round-topped type of oblong stack that has settled for four months. The stack is 20 feet wide, 30 feet long and has an over of 40 feet.

The answer is secured as follows:

a. Volume = (0.52 x 40) - (0.44 x 20) x 20 x 30 = 7,200 cubic feet

b. Table 3 shows that there are 470 cubic feet per ton of settled alfalfa

c. 7,200 ÷ 470 = 15 tons of hay

3. Volume of hay in round stacks
The rules or formulas used for oblong stacks do not apply to round stacks. But Table 2 (pages 4-5) gives the volume of round stacks when the circumference is between 45 and 98 feet and the over between 25 and 50 feet.

Calculate the volume of stacks having circumferences or overs greater or less than those given in Table 2 by using the following formula:

Volume = (0.04 x O) - (0.012 x C) x C²

In this formula, C equals the circumference or distance around the stack at the ground, and O equals the over or distance from the ground on one side over the peak to the ground on the other side (usually taking two measurements at right angles to each other and averaging them is best).

Thus, the computation of the volume of a large, round stack may be illustrated by the following example:

Example. You want to determine the amount of alfalfa hay in a round stack that is 100 feet in circumference and has an average over of 60 feet.

The answer is secured as follows:

a. Volume = (0.04 x 60) - (0.012 x 100) x (100)² = 12,000 cubic feet.

b. Table 1 shows that there are about 470 cubic feet per ton of settled alfalfa.

c. 12,000 ÷ 470 = 25.5 tons of hay.

Indoor hay and straw storage helps preserve quality and reduce dry-matter losses. Store hay and straw near loading or feeding areas. Use hay storage sheds according to the following chart.

Hay shed capacities.*

Shed Width Small
Square Bale Chopped Hay

(ft) ton/ft of length

24 2 1.9

30 2.6 2.3

36 3.1 2.8

40 3.4 3.1

48 4 3.7

* Shed has 20' high side walls.

Figure 1. Three common types of oblong or rectangular stacks.

(Source:Measuring Hay in Stacks, USDA Leaflet No. 72.)

Rather Use a Computer?

This publication contains a variety of helpful references under one cover. It is by no means complete. Sometimes the "hard copy" version is handy enough, but sometimes you would rather use a computer.

Many computer programs and calculators have conversions built into their memory. Stand-alone programs also are available free of charge or for purchase.

Convertis one "free" program that is worthy of note. Convertis an easy-to-use unit-conversion program that will convert the most popular units of distance, temperature, volume, time, speed, mass, power, density, pressure and energy, and it has the ability to create custom conversions.

Convertis available by going to:

http://joshmadison.com/software/convert

Click Here to view Table 2.

Bunker/Trench Silos and Silage Piles
Wet Forages

Approximate dry-matter capacities of bunker silos

Haycrop Silage
Dry-matter density is assumed to be 11.8 lbs DM/ft³ (Rotz, 1989).
Corn Silage
Dry-matter density is assumed to be 17.7 lbs DM/ft³ (Holter, 1983).

(length, ft) × (width, ft) × (average height, ft) × (dry matter density)
Capacity, tons DM= ——————————————————————————————
2000

Table 3.Horizontal silo capacity, wet tons.

Silo Floor Width (ft)

Depth 20 30 40 50 60 70 80 90 100

(feet) �� wet tons/10' length—————————————

10 40 60 80 100 120 140 160 180 200

12 50 70 95 120 145 170 190 215 240

14 55 85 110 140 170 195 225 250 280

16 65 95 130 160 190 225 255 290 320

18 70 110 145 180 215 250 290 325 360

20 80 120 160 200 240 280 320 360 400

65% moisture; 40 lb/ft³ or 50 ft³ = 1 ton; 1.25 ft³/bu. Silo assumed level full.
Capacities rounded to nearest 5 tons.
To calculate capacity of other silo sizes:
(silage depth, ft x silo width, ft x silo length, ft) ÷ 50.