The second part of forage budgeting looks at forage requirements, and requires a chart similar to Table 14.3. The forage requirement chart uses the following information:
The number of animals in each class. In practice, the classes are broken down in more detail than I’ve done in this example: A class would be established for breeding males, as well as for breeding females; wean-lings and yearlings would be broken into separate groups; and if you are running a dairy, high-producing cows would be separated from low-producing cows.
The average weight is your best guesstimate of the average weight of all the animals in a given class. Table 3.1 (p. 24) can be used to help develop this number if you don’t have a good sense of your animals’ approximate weights.
The total weight. Multiply the average weight by the number of animals within the class of livestock.
The intake factor is a multiplier based on the percent of body weight that each class requires in dry matter each day. This can be taken from Table 14.4.
The hay equivalent (HE). Multiply the intake factor by the total weight of animals within a class to come up with a hay equivalent. Remember though, that the HE is simply a measure of quantity. For animals to perform well, the feed needs to be of high quality, and when it is the animals can eat even more than the percent factors given. In fact, fast-growing and hard-working animals can sometimes eat as much as 6 percent of their body weight per day when feed quality is at its best, which translates into high production (growth, milk, fiber, breeding).
Table 14.3
JONES FARM FORAGE BUDGET — PLANNED FORAGE REQUIREMENTS (FR)
Table 14.4
INTAKE FACTORS FOR CALCULATING FORAGE REQUIREMENTS
Calculating Carrying Capacity
The carrying capacity is an approximation of how many animal units your farm can carry. There are two different ways to calculate carrying capacity: the first is more accurate and is based on your forage budget figures; the second is a more “quick and dirty” number, to be used in cases when you don’t have a forage budget. Either way, the carrying capacity represents a theoretical stocking rate. We’ll look at examples of each type.
The More Precise Method. With the estimates for forage production (FPHE) and forage requirements (FRHE) that you calculated in Tables 14.1 and 14.3, estimate carrying capacity with the following formula:
For example, using the Joneses’ figures from the previous charts, carrying capacity would equal 70 AUs. The Joneses have 68 AUs, so they are slightly under-stocked. The calculation is:
Note: In this equation the hay equivalent values cancel out, and only animal units remain.
Reserving extra carrying capacity isn’t a half-bad idea, especially when you’re starting out. This calculation is designed to provide a 25 percent reserve, which allows feed for wildlife and some cushion for those times when the animals consume higher percentages of feed. (If you want to increase the reserve percentage, increase the 1.25 variable accordingly: 30 percent would be 1.3. If you don’t want to reserve as much, lower the variable: 15 percent would be 1.15.) Gil and Jenny shoot for a 25 percent reserve but have even a little more than that, as they still have feed for two additional animal units. If they have a bumper crop that exceeds their estimate, they take off extra hay. If they have a dry summer, they know that a surplus can act as a buffer.
The Quick and Dirty Method. The second version of the carrying capacity formula does not provide the level of accuracy that the first version does, but there are cases where it comes in handy. The formula for the rougher estimate is:
where CC = the estimated animal units, and
FPHE = an estimated forage production
*Or divided by 6,866 if you are working in metric figures.
Let’s look at a few examples.
Example 1. Tom and Karen Wilson are thinking about converting all their tillable ground to pasture and purchasing additional livestock. They know their tillable ground is of high quality, and they have a long growing season, so Tom estimates they could yield 4.5 tons/acre (10,089 kg/ha) from these fields. First he multiplies 4.5 tons/acre by 120 acres (49 ha) to come up with 540 tons (494,361 kg) of FPHE. Next, he divides this figure by 7.5 (6,866) to come up with an estimated carrying capacity of 72 AU.
Example 2. A doctor from Boston just purchased the farm across the road from Gary and Michelle Miller. He’s made a proposition: They can use his land for grazing for free, if they will keep an eye on two horses he wants to buy for his wife and daughter. The doctor will benefit by having the farm “farmed,” because if no agricultural pursuit is taking place there, the county assessor will raise his taxes. Gary and Michelle tell the doctor that they’ll get back to him in a week or two.
The farm has about 45 acres (18 ha) of reasonably good permanent pasture, is well fenced on the perimeter, and has water available in the pasture. Gary and Michelle don’t need any additional pasture for their existing herd, so if they take the doctor up on his offer, they’ll have to purchase additional animals. After some discussion, they decide that if they do run animals on the doctor’s farm, they will run stockers, as additional breeding stock would increase their winter chores more than they could cope with.
Gary and Michelle estimate that the average yield on the doctor’s farm would be about 3.5 tons per acre (7,847 kg/ha), so the carrying capacity would be 21 AU (3.5 x 45 / 7.5) or (7,847 x 18 / 6,866). But that carrying capacity would be for the full year, and by using stocker animals, Gary and Michelle will only be responsible for the animals for about half the year. This means that they’ll be able to double the carrying capacity during the fraction of the year they’ll run animals on the doctor’s farm, so they could carry about 42 stocker animals for 6 months — quite a boon! (If you are thinking about running stockers for a fraction of a year, multiply the carrying capacity by 12, and then divide the number of months you plan to keep the stockers.)
Before calling the doctor to accept his offer, Gary and Michelle use the planning guidelines in chapter 12 to see if this enterprise will move them closer to their goal. In this case, it appears to be a winner, so they call the doctor to let him know they’ll work with him.
Reading Topographic Maps
If you’ve never studied a topographic map, looking at one for the first time may be a little intimidating. Once you get the hang of it, though, topos are easy to use and they supply a remarkable amount of information.
Topographic maps are often referred to as quadrangles. Each quadrangle is designated by a name, generally the name of a prominent town or geological feature within that quadrangle (Figure 14.5).
Quadrangle simply refers to an area that is bounded by lines of longitude running north and south, and lines of latitude running east and west. Every single point on the earth can be described by the intersection of lines of longitude and lines of latitude.
Lines of longitude and latitude can be expressed in terms of degrees, minutes, and seconds; 360 degrees makes a complete circle. There are 60 minutes in each degree, and 60 seconds in each minute. Graphically, a minute is noted by the ' mark, and a second is noted by " mark. So a 7.5-minute map shows an area s of a degree tall by s of a degree wide, and 7.5 minutes could also be written as 7'30". The four corners of the map give the degrees, minutes, and seconds north of the equator, or west of the prime meridian (a longitudinal line that goes through London, England). As I sit typing, south of Hartsel, Colorado, I am at 38°57'10" north of the equator, and 108°47'05" west of the prime meridian.
In the late 1700s, a Public Land Survey was started, and as a result topos for most U.S. states show section, township, and range lines, though some maps of eastern states are not configured this way. The sections are 1-square-mile blocks, and are numbered from 1 to 36. Each township contains 36 square miles. Through much of the country, legal descriptions of all larger tracts of land are based on the section, township, and range description.
A graphic display on the lower portion of each quadrangle map shows the direction of both
true north and magnetic north. True north runs in the same direction as the lines of longitude. Magnetic north is different from true north because compasses aren’t attracted to true north — they are attracted to the magnetic pole, which is located to the west of Hudson Bay in Canada. The difference between true north and magnetic north is called the magnetic declination, and changes as you move around the country.
Maps all have a scale, which establishes the ratio between the distance shown on the map and the distance in real-life terms. Typical scales for topographic maps are 1:24,000 (7.5 minute), 1:62,500 and 1:250,000. When the scale is 1:24,000, 1 inch (2.5 cm) on the map equals 24,000 (60,000 cm) inches on the ground, which is equivalent to 2,000 feet (600 m). A graphic scale is printed on the bottom of maps that shows feet, miles, and kilometers.
Other information displayed at the bottom of most topographic maps includes a location map, description of symbols used on the map, and information about when and how the map was prepared. The names of surrounding quadrangles are written around in the edges of the map in parentheses.
One of the most useful things about a topographic map is its visual representation of contours, or elevations. Contour lines are light brown, squiggly lines that connect all the points located at a given elevation. Contour lines form a V when they cross streams; in fact, even if a water body isn’t shown, if you see is a V in a contour line you’ll know that water runs down at that point on the ground. A closed circle represents the top of a hill. Hatch marks along the edge of a contour line represent a depression.
A number known as the contour interval is given on the bottom of the map. If the given interval is 40 feet (12.2 m), for example, then each contour line represents land whose elevation is 40 feet (12.2 m) higher, or 40 feet (12.2 m) lower, than that of the line next to it. Contour lines may be heavy (these give the contour’s elevation) or lighter (these don’t). If a point lies on a contour line, you can read its elevation directly from the line. If it is between two contour lines, you can estimate its elevation as some amount between the two lines shown.
Figure 14.5. Topographic maps indicate road classifications, bodies of water, and land elevation.
(Reprinted from Hartsel Quadrangle c.1956, U.S. Geological Survey, Denver, CO.)
Developing Your Grazing Plan
To develop your own grazing plan, first go through the forage-budgeting process. Depending on circumstances, you may make a conscious choice to purchase in your winter forage by buying hay (or round bales of cornstalks, or silage, and so on). This decision makes good sense for many small operations; it allows you to maximize your carrying capacity during the growing season. If you choose to follow this route, you can make adjustments to your grazing-season carrying capacity by multiplying the carrying capacity by 12 and then dividing by the number of months you’ll graze, like the Miller’s did for their stocker operation.
Once you have assessed your forage requirements, you can establish a carrying capacity for your land. Establish a reserve quantity that you feel comfortable with. Depending on your circumstances, anywhere between 15 and 30 percent reserve is a good place to shoot for.
Set up a planning schedule like the one in Table 14.5. It helps you plan where you’ll feed in winter, approximately when you expect to begin grazing, when you expect to end, and which paddock you’ll begin with.
The Landscape Plan
The process of landscape planning begins with mapping the farm. Mapping is a practice that allows you to design a well-thought-out, ideal landscape. It is an integral step in long-term development.
The mapping process is easiest if you first acquire all the existing maps and aerial photos you can find for your farm — though if your farm is very small (maybe less than 20 acres, or 8 ha), you can probably do the map without this step. The U.S. Geological Survey (USGS) has both contour maps and aerial photos for most of the United States. Contour maps show elevations, watercourses, and general vegetation. For the highest level of detail in a USGS map, request a 7.5-minute series topographic map, which has a scale of 1:24,000 (1 inch to 24,000 inches or approximately 2,000 feet). In the western states, the Bureau of Land Management and the Forest Service also have good maps.
Gather as many maps that show your farm as possible. When you set out on this task, you may be surprised at just how much information has already been generated about your piece of land; for example, the USDA has soils maps for most of the country that describe the characteristics of the soil in detail. Consider your search an adventure.
Once you’ve put together your map collection, study it. Tape copies on walls, darken in your property lines, and try to absorb as much of the information as possible. Try to picture your farm within the larger area of the map: how it sits in the watershed, its proximity to existing natural features, industries, communities, roads, and so on. For a visualization exercise, look at the maps and ask yourself, “What would this look like if I were a bird, flying over the whole thing?”
After you’ve allowed time to reflect on your landscape — a week, a month, maybe more — it’s time to begin mapping what you want to see in the future. Mapping can easily be done on a computer with a drawing program, and this approach allows you to print out working copies for everyone to use. When using a pencil and paper, you’ll need to make copy-machine copies for some steps. It is easiest to begin mapping with paper that has a grid superimposed on it; ask for engineering-ruled pads at an office-supply store. If working with pencil and paper, also purchase plastic sheets, like those used for overhead projection slides, and grease pencils or dry-erase markers. These can be used for superimposing various ideas on one map.
Mapping Your Farm
On your first map, show property lines. Show existing natural features, such as ponds, wetlands, hillsides, or wooded areas, and any areas where serious disturbance or erosion has taken place, which will need to be repaired. The only human-made improvements that should be shown on this map are those that absolutely can’t be moved (such as your house) or that you have absolutely no control over (for example, a major county road that cuts the property in half). Existing fences, watering points, field roads, and the myriad other “improvements” that are found on most farms should be left off, so they don’t fog your vision of what you want the land to look like in the future (Figure 14.6). If you are working on a computer, print out enough copies of this first map for everyone in the family, hired hands, or other folks who are helping you with planning; when working with pencil and paper, take this version to town and make copies on a copy machine.
Table 14.5
PLANNING SCHEDULE
Now each person should take their map and begin drawing what they would like the landscape to look like if they could come back in a 100 years: a series of ponds along an existing stream, healthy trees growing on the hills, areas of open grasslands. Once everyone has gone through this exercise, compare notes. Chances are the visions won’t be too far apart; if there are major discrepancies, put everyone’s versions on a wall and study them for a week or two. Then join together again and try to decide if one version, or a combination of several, best meets the goal you’ve already set as a group. Redraw a permanent copy of your future look, or vision map, to keep as a reference.
Next, take one of the extra copies of your first map and use the data you’ve developed from studying the topographic map of your farm to approximate drainage lines, or the places that water will run downhill. On all but the flattest pieces of ground, there are multiple drainages; some may be home to a permanent stream, others may simply be runoff drainage paths during rain and snowmelt. Use a heavy line for big drainages and creeks, and a dashed line for minor drainages. Walk your land, after a rain or during snowmelt, with a copy of the drainage map to confirm that you show the drainages fairly accurately.
SOURCES FOR MAPS AND AERIAL PHOTOS
County governments often have maps that show roads, section lines, and property lines; check first with the assessor’s office
; Local soil and water conservation districts
USDA offices — Natural Resources Conservation Service (NRCS) and Farm Services Agency (FSA) offices are located throughout most of the country
State foresters
State mineral offices
U.S. Coast Guard, if your property is on a navigable water body
Take time to study your drainage-area map and your vision map. Once you feel comfortable with how the drainage and your vision wed to each other, lay out major areas of the farm: woodlots, crop areas if you plan to do some cropping (which should be rotated into pasture for at least 2 out of every 5 years), permanent pastures, field roads. This layout should include existing features as well as features you want to develop in the future. For example, maybe you want to set aside an area for woody agriculture (fruit and nut trees), or a spot to build a rental guest cabin.
Paddock Design
Now it’s time to begin designing fencing systems and water systems. The first step in this process is to determine how many permanent paddocks you ultimately want to place on your site. As you learned in chapter 4, the more paddocks you have, the better, especially up to thirty. But large paddocks can be subdivided into smaller paddocks using portable temporary wire.
A good way to determine an appropriate number of permanent paddocks is to use the relationship that exists between average recovery periods (RP), grazing periods (GP), and total paddock numbers (TP), which can be expressed mathematically by the equation:
Small-Scale Livestock Farming Page 29