A quarterly news publication of The Ohio State University Extension, Editors: Clif Little and Mark Sulc
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Contents:

• OSU Hires New Forage Specialist
• Grazing Alfalfa in the Fall
• Revisiting Extending the Grazing Season
• Seasonal Dairying
• Sweetening the Soil

[top] OSU Hires New Forage Specialist

Dr. Dave Barker recently joined Ohio State University's Department of Horticulture and Crop Sciences. Dr. Barker will have an appointment which is 60% research and 40% teaching in forage science. Dr. Barker is from AgResearch, Palmerston North, New Zealand and comes to us with 18 years experience, primarily in grazing. His research interests include species mixtures, plant water relations and grazing.

[top] Grazing Alfalfa in the Fall - Mark Sulc, OSU Forage Specialist

Grazing alfalfa in the fall is of interest because of its high quality and the fact that making hay is difficult this time of year. Producers must weigh the opportunity for gain with fall grazed alfalfa against the risk of subsequent stand injury. Anytime alfalfa is defoliated in the fall there is increased risk of winter injury. How much risk is dependent on many variables.

Physiologically, alfalfa needs a fall rest period to accumulate carbohydrate and energy reserves for the winter. Complete defoliation during the critical fall period (mid September to a killing frost) interrupts this process and can be very harmful to the stand. Grazing can be controlled so alfalfa plants are grazed lightly, which should allow photosynthesis and energy reserve accumulation to continue. Some studies have demonstrated that light fall grazing is less harmful than complete defoliation.

If grazing alfalfa during the fall, make sure that at least 8 inches of active growth remains at all times. To accomplish this, rotate animals more frequently or reduce stocking rates. With top grazing, animals will be consuming lush, high quality forage. Precautions against bloat are even more important than when the whole plant is grazed.

To maximize energy reserves in alfalfa, allow a fall rest period and only graze alfalfa after mid to late October. Better yet, wait until after a killing frost. A killing frost for alfalfa is 25 F for several hours, and often for two consecutive nights. But late fall grazing is not without risk. Removal of plant cover by close grazing can dramatically increase the risk of plant heaving in late winter on heavy soils. Leave at least six inches of stubble going into the winter.

Anytime alfalfa is grazed, and especially during the fall, make sure soils are dry and firm. Grazing alfalfa when soils are soft and wet is a sure recipe for severe damage to crowns and subsequent stand loss over the winter.

Frosted and frozen alfalfa does not contain toxic compounds. It is likely, however, that a slightly higher potential for bloat exists for one or two days after a frost or freeze. The safest management is to wait a few days before grazing after a killing freeze, when the forage begins to dry.

Always use good bloat management practices whenever alfalfa is being grazed.

[Top] Revisiting Extending the Grazing Season - Daryl Clark Ag/NR Agent, OSU Extension

Background

Ruminant livestock's primary diet is forages. However, about 60% of the growth of cool season forages occurs during April, May, and June. Forage quality is greatly reduced at maturity, therefore, "the dilemma" cool season forage growth occurs in the spring, but ruminant livestock need to eat each day.

Normally, ruminant livestock producers have solved this dilemma by storing spring produced forage as hay and silage to feed during months of no or limited forage growth. However, this is an expensive procedure which costs as much as 90% of the out-of-pocket production costs for producers.

Why extended grazing?

1. The primary interest in extending the grazing season has been to reduce production cost.
2. Forage quality in extended grazing is usually equal to or superior to stored forage.
3. In hilly terrain, reduced soil erosion can result.
4. Organic matter can also be recycled to areas needing it most.
5. Reduced production costs also make production agriculture more likely to be a continuing part of economic development in rural areas.

Reduced cost guidelines

A number of options to extend grazing have been utilized. However, to be useful and sustainable they must be evaluated in terms of the Reduce cost guidelines

1. In some cases, establishment costs of annuals plus replanting ground cover following grazing has exceeded returns.
2. Establishment often requires purchase or rental of equipment which is an additional cost.
3. Costs of preventing soil erosion and compaction during wet seasons can also be substantial in annual forage plantings.

Random Observations

1. Most producers can stockpile as high or higher quality forage that they can store as hay.
2. Producers can stockpile higher quality forage than may be needed by their present management system. The livestock management system may need to be evaluated.
3. Legumes tend to deteriorate more readily than grass after freezing and should be grazed earlier.
4. Stockpiling from perennial forages causes less environmental concerns from soil damaged by grazing livestock B especially where tall fescue is a part of the forage mix.
5. Perennial forage stands can be maintained in an extended grazing format (root reserves can be well managed).
6. Livestock nutrient management can be environmentally sound in an extended grazing plan.
7. The irregular terrain of eastern Ohio can be to a producer's advantage when planning grazing sequence during winter months.
8. In order to utilize stockpiled forage well, a system to limit livestock access to forage is needed to receive full advantage of the cost saving.

Summary

Because of the cost saving advantage, most producers should consider utilizing extended grazing. An extended grazing plan can offer high quality forage to meet the nutritional needs of all stages of the livestock production cycle. In the future one of the greatest benefits may be from reducing the environmental impact of livestock production.

[Top] Seasonal Dairying - Thomas E. Noyes Dairy Agent, OSU Extension

Many dairy producers switch to MIG for the many benefits grazing provide, such as lower investment, lower operating cost, more profit and hopefully less stress for cows and people. Should adopting a seasonal dairy be part of switching to grazing?

There is no easy or definite answer to being a seasonal dairy and there are different seasonal alternatives. Some that I have seen adopted include all spring calving with total dry off at Christmas; spring calving with an extended calving window and drying off 2 to 2/3 of the cows at Christmas thereby milking 1/3 to 2 of the cows in the winter; fall calving herds and herds that have a spring and a fall calving season. Let me address some of the factors for each of these. Whatever you decide should fit your farm, your facilities and your lifestyle.

Whatever one decides to develop a seasonal dairy there are some important factors that must be addressed regardless of what type of seasonal dairy is adopted. First take a look at your physical facilities and it's ability to handle a lot of cows calving at one time with adequate calf raising facilities. Delaying some calvings in a spring calving herd until it can be accomplished outdoors on pasture will help. However, this will shorten lactation's, produce less milk and reduce income if you plan on drying off at Christmas. This is not a problem with fall freshening herds, less of a problem for a herd with two calving seasons (spring and fall). This bunched calving can also put stress on the farm owner, managers and employees. One needs to really gear-up to handle a lot of calvings, fresh cows, first lactation heifers and raising calves.

Milking facilities and milk storage - when cows calve as a bunch they reach peak milk at approximately the same time then milking time is lengthened. Because of all the cows peaking at the same time you must have a large enough bulk tank. Can you get milk picked up every day?

Let's take a look at some advantages of a spring calving herd. The most abundant forage supply and peak quality is available when the cows are reaching maximum milk production. Reproductively it is the natural time of year to breed cows. It reduces the costs of heifer raising as you can use more pasture for heifers and even extended the grazing season. Your feed costs are lower in the fall when the cows come off grass because the cows are in mid to late lactation. Two major disadvantages are lowered milk prices with the spring flush and potential breeding difficulties during a hot summer. (Try to breed cows in May and June.)

Now for a fall season herd this may work the best for Holsteins. During the host summer months they will be dry thus reducing potential breeding problems. The fall calving cows (August, September) will still have excellent quality pasture for peak milk. However, feed costs will be higher going into the winter as you have cows in early lactation. To offset this will be the higher milk prices and this year the fall premium are substantial. Having all cows dry during the summer allows more time for cropping (if you still farm) and you have time off when the kids are out of school making vacations possible.

For the herd owner that wants some of both a spring and fall calving herd it can be accomplished with management. When fall premium are high you might want to have peak milk in September, October and November. A herd calving in March and April and August and September will still get you away from cows calving in January, having to raise calves in the winter and less stress on the facilities with two calving windows.

So is a seasonal herd for you? That will depend on your goals, your management and your facilities. Our milk markets would like to see a steady year around supply of milk. We will never be able to operate like New Zealand where they need only 10-15% of the milk for fluid to be produced year around.

[Top] Sweetening the Soil - Clif Little Ag/NR Agent, OSU Extension

For many years we've referred to correcting soil pH as sweetening the soil. It seems to be universally agreed upon that maintaining proper pH for plant growth is very important. What is less clear is why pH drops, what is the lime recommendation based on, and what is the most economical source of lime?

Why soil pH drops is fairly easy to explain. There are many factors, both natural and managed, which contribute to increasing acidity. Basic actions, Calcium (Ca), Magnesium (Mg), Potassium (K), and Sodium (Na), may leach in the soil profile reducing pH. The parent material which makes up the soil may release basic actions and tend to increase soil pH, or release Aluminum (Al) and Iron (Fe) which tends to decrease soil pH. The release of Al by weathering is the most common source of increased acidity. Plant removal by animal or mechanical harvest may also remove basic actions, reducing soil pH. Additional reasons for pH drops include acid rain, application of ammonium and potassium fertilizers, and organic matter decomposition. The type of vegetation grown may also influence soil pH. For example, deep-rooted species such as warm-season grasses may absorb basic actions from deeper soil and bring them to the surface.

Lime recommendations are based on many factors. Among the most important are soil pH, soil buffering capacity, crop to be grown, plow depth, and lime history.

Soil pH identifies the active acidity or alkalinity of a soil solution. The pH measurement is expressed as a measurement of hydrogen ion activity or concentration in a solution. The pH scale is from 1 to 14. A neutral solution of soil has a value of 7.0. The ability of lime to neutralize pH is measured by Effective Neutralizing Power (ENP). The effective neutralizing power of lime is expressed on the basis of pounds per ton as a percentage of the fineness index, multiplied by the total neutralizing power and percentage of dry matter. Let's compare these two liming products:

Product 1: has an ENP of 1286 lbs./ton
Product 2: has an ENP of 1702 lbs/ton

The cost of each is $15/ton. If our soil test calls for an application of 2000 lbs. of calcium carbonate equivalent, what is the best choice and how much do we need?

Best choice: Take the cost divided by the ENP

Product 1 = $15 / 1286 lbs. = .011/lb./ENP
Product 2 = $15 / 1702 lbs. = .008 /lb./ENP

As you can see, product 2 has the lowest cost per pound of neutralizing value. This however does not reflect total cost. In order to calculate total cost, we must determine our application rate.

Buffer capacity or actin exchange capacity of the soil best explains differences in lime requirements. The buffer capacity of a soil reflects the resistance to a change in pH. The amount of clay and organic matter influence buffer capacity. This simple notion explains why soils of the same pH may have a different lime requirement. For instance, it may require much more lime to raise the pH of a clay soil than will be required to raise the pH of a sandy soil.

Liming materials vary significantly in terms of purity, fineness, and moisture. These factors help us select the most economical source of lime and determines the application rate of lime. Fortunately, state law, sections 905.51 to 905.66 of the Ohio Revised Code require lime manufacturers to label these products. The most important item on the lime product label for determining application rate and value is the Effective Neutralizing Power.

The application rate of each:

Product 1 = 1286 lbs. ENP / 2000 lbs. = .643
Recommended rate 2000 lbs. / .643 = 3110 lbs. to apply/Acre 

Product 2 = 1702 lbs. ENP / 2000 lbs. = .851
Recommended rate 2000 lbs. / .851 = 2350 lbs. to apply/Arce

The cost of each:

Product 1 = 3110 lbs. / 2000 lb/ton = 1.55 ton/A x $15/ton = $23.25/Acre
     plus spreading cost, we'll say $4/ton 

1.55 ton/A x $4/ton = $6.20/A
     Total Cost $29.45/Acre

Product 2 = 2350 lbs. / 2000 lb/ton = 1.17 ton/A x $15/ton = $17.62/Acre
     plus spreading cost:

1.17 ton/A x $4/ton = $4.68/A
     Total Cost $22.30/Acre

The difference in total cost of these two liming materials at a 1 ton/acre recommendation is more than $7/Acre. What is your soil test calling for? Are you applying the correct amount of lime? Even with very few liming materials available to choose from, significant differences exist in value.

All educational programs and activities conducted by Ohio State University Extension are available to all potential clientele on a nondiscriminatory basis without regard to race, color, creed, religion, sexual orientation, national origin, sex, age, handicap or Vietnam-era veteran status. Keith L. Smith, Associate Vice President for Ag. Admin. and Director, OSU Extension. TDD No. 800-589-8292 (Ohio only) or 614-292-1868.

Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, Keith L. Smith, Director, Ohio State University Extension.

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