Welcome to the Winter 1998 Forager

Kura clover (Trifolium ambiguum M. Bieb.) is a relatively new forage legume in North American that has potential to be a major component of Wisconsin’s forage-livestock industries. Kura clover is native to southeastern Europe and western Asia, and grows naturally in habitats ranging from poorly drained valley bottoms to mountain meadows at elevations greater than 10,000 feet. Although introduced into the USA in 1911, commercial development of kura clover was limited by ineffective nodulation, seed production difficulties and poor seedling vigor.

Rhizobia capable of effectively nodulating kura clover have been identified, and are now available through several commercial sources. Although seed production difficulties such as low and inconsistent seed yields and difficult threshing still are problems, a handful of seedsmen are now producing kura clover seed, and it is commercially available from several sources within the state. Seedling vigor is still a problem, but we now have guidelines that will allow us to maximize chances for successful establishment.

We have over the last several years gained some appreciation for the adaptation, management and productivity of this new legume. Our knowledge about kura clover will expand and recommendations for management of this crop will be refined over the next several decades, but we will outline what we know about it now.

Adaptation

Kura clover is widely adapted to the temperate regions of the world and has performed especially well in the cooler temperate regions. It is known to survive very dry conditions, and is more productive than white clover in the dry highland of New Zealand. In Wisconsin, we have observed that kura clover tends to go dormant sooner than alfalfa or red clover in response to drought. So, although the plant persists through dry periods, productivity is depressed. We have had kura clover in production near Arlington, Wisconsin for 8 years with no sign of stand decline, and stands are still strong after 4 years in the poorly drained soils near Marshfield. Excellent stands have also been established in pastures near Lancaster and Spooner. We conclude that kura clover is persistent and productive in all regions of the state and on most agriculturally useful soils of Wisconsin. Based on our observations and the literature, it seems that kura clover pH and soil fertility requirements are similar to red clover, i.e. it will do well under conditions that are less than optimal for alfalfa.

Characteristics

The characteristic that makes kura clover unique among the forage legumes adapted to Wisconsin is its massive rhizome (underground stem) system. The underground mass (rhizomes and roots) of a mature stand of kura clover has been reported to be as high as 9 tons per acre. Kura clover persistence is probably associated with the large rhizome system having large numbers of buds at various depths in the soil. When portions of plants are damaged by cattle, machinery or freezing, new growth is initiated from buds on undamaged portions of the plant. We have found that individual kura clover plants can spread to a diameter of three feet over a 3-year period if it is not competing with other plants. In mixtures with grass, rhizome growth is less than half that.

Kura clover is a very leafy plant with stem production occurring primarily only in the first spring growth. During the rest of the season, leaves are produced from short stems at or near the soil surface. Leaves are usually larger than red clover leaves and have no hairs. Because of the high proportion of leaves in kura clover forage, it is very high quality with protein concentrations ranging between 18 and 25%, and neutral detergent fiber concentrations between 25 and 40% in Wisconsin conditions.

Management

Kura clover has the reputation of being difficult to establish. The above-ground portion of kura clover seedlings is very slow to develop because much of the energy is used early for root development. Rapidly growing weeds or grass in existing pastures can be very competitive with developing kura clover seedling and cause stand failures (Figure 1). In research plots, we have successfully used clipping, grazing and herbicides for control of weeds or pasture grasses. On an experimental basis, we have found that most herbicides compatible with red clover also work with kura clover, however, label laws must be followed carefully for commercial applications.

Figure 1. Excellent establishment of Kura Clover with herbicide suppression of weeds on right, and poor establishment in the sprayer skip on the left. Photo was taken in September after sowing in May.

Optimum seeding rates for kura clover are probably slightly lower than for alfalfa. We have had excellent success with 8 lb/acre of kura clover seed when sown with grasses. Other Wisconsin research has demonstrated quicker ground cover by kura clover and less weed pressure if rates of up to 18 lb/acres are sown. We have had success sowing a small amount of birdsfoot trefoil with kura clover in order to increase forage yield in the first and second seasons. The birdsfoot trefoil will die out after a few years.

Kura clover requires a particular strain of rhizobia (different from red clover and alfalfa) for effective nodulation. If the seed is not already inoculated, your seed supplier should be able to provide the rhizobia and instructions on how to apply it. Seed should be planted as soon after inoculation as possible--preferably within hours. Mistakes in handling the inoculant or inoculated seed will surely result in stand failure because the clover will not fix nitrogen and not compete with weeds or other forage plants. Mixtures of nodulated kura clover with grass have yielded the same as grass fertilized with from 150 to 300 pounds of nitrogen fertilizer, depending on grass species.

Kura clover can be grown alone or in mixtures with grass. We have successfully grown it in mixtures with Kentucky bluegrass, smooth bromegrass, orchardgrass and tall fescue. Thus, the grass of choice should be the grass that a producer feels most comfortable with. Since the quality of kura clover is so high, it is not difficult to develop a grazing or hay harvesting system that results in neutral detergent fiber concentrations low enough for rations of dairy cows.

Productivity

The yield potential of a good stand of kura clover is about 80% that of a good stand of alfalfa, based on Wisconsin and Minnesota research. The lower yields are related to the large investment that the plant makes to below ground growth and energy storage, slow regrowth after defoliation and relatively early onset of dormancy in the autumn. These characteristics are also associated with Kura clover persistence.

Kura clover is affected little by grazing or harvest frequency of from three to five defoliations per season. Since regrowth originates from at or below the soil surface, defoliation to ground level is not detrimental to the plant, and in fact, will result in maximum yields. We have observed encroachment of perennial weeds, especially dandelions, in kura clover stands defoliated frequently and to short stubble height.

Persistence

Kura clover is the most persistent forage legume commercially available for use in Wisconsin. Conditions for winter kill of alfalfa and red clover in 1994-95 did not affect kura clover or cicer milkvetch, another legume with rhizomes (Table 1). The massive rhizome and root system represents a large underground “bud bank” for regrowth to originate from after damage from wheel traffic, animal treading, freezing or other. We have not observed frost heaving in kura clover, and this is also probably associated with the extensive rhizome system. The rhizome is also a storage organ for carbohydrates that are used as a source of energy for regrowth and after defoliation.

Table 1. Total season yields of legumes harvested four times each year at Arlington, WI.
Legume	1994	1995	1996	1997
	-----------tons/acre-----------
Alfalfa	4.8a¹	2.5	2.0b	2.3b
Red Clover	4.6a	2.8	1.7b	2.3b
Birdsfoot Trefoil	3.4b	3.0	2.4b	2.3b
Kura Clover	3.4b	2.8	2.9a	3.6a

¹Legumes were established in 1993 and in subsequent years four harvests were taken before Sept. 1. Means within a column followed by the same letter are not different at p=0.05.

No significant disease problems are known for kura clover, however, some insects that damage other legumes (such as potato leafhopper) also affect kura clover. We have had kura clover growing in mixtures with grasses and harvested five times per season to a 1.5 inch height for the last eight years with no sign of decline. Researchers in Minnesota have grazed kura clover for 12 years and those pastures still have an excellent stand of kura clover. Observations from Wisconsin, Minnesota, and other parts of the world suggest that, once established, kura clover will be a permanent component of a pasture or hayfield.

The portion of the crude protein (CP) in feedstuffs, which is degraded by bacteria in the rumen to peptides, amino acids and ammonia, is referred to as rumen degradable protein (RDP). The non-degraded CP in feedstuffs which passes to the small intestine is called rumen undegradable protein (RUP) or more commonly “by-pass” protein. Nonprotein nitrogen (NPN) from feedstuffs, urea or ammoniated silage is part of the RDP. Adequate intake of RDP is needed to optimize carbohydrate (fiber and starch) digestion in the rumen, and maximize the production of microbial protein. Both microbial protein and RUP flow to the small intestine where they are degraded into amino acids and absorbed into the body for maintenance and production. Intake of RUP or by-pass protein must be balanced to compliment both the amount and amino acid composition of microbial protein flowing to the small intestine. Dairy cows consuming about 50 pounds of dry matter per day will produce about 5 pounds of microbial protein per day. If the cow is producing 80 pounds of milk per day, her protein requirement is about 8 pounds per day, and therefore, the RUP or bypass protein needs to add about 3 pounds of protein per day to meet her protein requirement.

New RUP Test

To date, no standard laboratory methods are available for measuring RUP in feedstuffs. Until now, almost all RUP values for feedstuffs have been determined in research laboratories involving laborious methods and very few samples. Pat Hoffman, dairy scientist, University of Wisconsin-Marshfield, has recently developed a method of determining RUP which can be standardized and repeatable to analyze legume and legume-grass silages. More important, he has developed Near Infrared Reflectance Spectroscopy (NIRS) calibrations to allow commercial laboratories to predict RUP values in legume and legume-grass silages, See Figure. This new test using NIRS techniques now allows anyone to have a much more accurate value of the RUP in their legume or legume-grass silage. Prior to this, most computer ration formulation programs only used a table value for all silages, which was based on a very few number of samples. This RUP test, along with a protein solubility and CP test, will give a very good indication of how much protein in the feedstuffs will be degraded in the rumen, and how much will “bypass” into the small intestine.

Figure. Relationship of Crude Protein Remaining (CPR) after 24-hour ruminal fermentation of timothy and alfalfa silages by NIRS or in situ analysis.

SOURCE: Hoffman, P. C. et al. 1998. Journal of Dairy Science. In Press.

Ranges of RUP in Forages

Forages, grains and by-product feeds have different RUP values. Some of what determines RUP in feedstuffs is the composition of the protein, maturity of forage crop, extent of fermentation during ensiling and how much heating the feedstuffs have been subjected to.

Rumen undegraded protein (RUP, by-pass protein) is most commonly expressed as a percent of CP. Thus, if a sample had 18% CP (dry matter basis) and has 33% RUP, 6% of the CP on a dry matter basis would not be broken down in the rumen and would escape to the small intestine. These values assume cows have reasonably high dry matter intakes and rumen passage rates of 6% per hour. Values of RUP would be lower for the same feed at lower intake levels. The RDP content of the sample in this example is 100 - 33% RUP = 67% RDP expressed as a percent of the CP, or 12% of the dry matter (18% CP x .67 RDP).

The table below shows the generally accepted RUP mean and normal range for forages fed to dairy cows. The standard deviation is the +/- range that includes two-thirds of the samples, i.e. two-thirds of the legume grass silages fall between 22%, -3.7 percentage points and 22%, +3.7 percentage points of RUP express as a percentage of CP.

Table 1. Ruminal undegradable protein (RUP)

for various forages at three maturities.

	Maturity
Legumes	Late Vegetative	Bud	¼ Bloom
Alfalfa	16	23	28
Birdsfoot Trefoil	14	16	25
Red Clover	14	19	30
Grasses	2^nd node	Boot	Inflorescence
Bromegrass	24	28	36
Orchardgrass	18	25	29
Perennial ryegrass	12	14	32
Quackgrass	20	36	51
Timothy	16	28	45

SOURCE: Hoffman and Co-workers (1992). Journal of Dairy Sci Abstr. 75:210.

Within the ranges expressed in the table, the following trends occur:

· Forage plants harvested when more mature tend to be higher in RUP than immature material. The degree of change is frequently 5 to 8% RUP.

· Forage plants with high levels of Nonprotein nitrogen (due to high fertilization, drought stress, immaturity, etc.) will tend to have low RUP values.

· Fermentation of silages also breaks down CP through a process called proteolysis. Thus, fermented forages tend to be lower in RUP than fresh chopped plant materials or dry hay. The amount of CP breakdown caused by proteolysis is related to moisture content of the silage (e.g. higher moisture = greater proteolysis), but is variable depending on fermentation conditions.

· Heat damage, either in a hay bale or silage made too dry, will tend to increase the amount of RUP. The amount of increase depends on the severity of heat damage. ADFIN (acid detergent fiber insoluble nitrogen) is a measure of the amount of nitrogen (crude protein) retained in the ADF fraction. This tends to increase with heat damage and has been used as an indicator of this type of damage. However, ADF-CP has a low correlation with RUP, and it is not predicted well by NIRS.

Why Should You Test For RUP?

Forages account for 40 to 50% of the dry matter in most lactating dairy cow diets. With an accurate measure of the RUP in the legume/grass forage, the amount and type of protein supplement needed to optimize rumen fermentation and provide maximal flow of amino acids to the small intestine can be determined. For example, suppose a cow eats 24 pounds of haylage dry matter per day. The CP content of the haylage is 20%, dry matter basis. If the haylage was harvested in the late vegetation stage, the RUP content shown in Table 1 is 16% of the CP. However, if it was harvested at ¼ bloom, the RUP content is 28% of the CP or a difference between the vegetative and ¼ bloom of 11%. At 24 pounds of haylage intake, this difference is .53 pounds of protein (24lb x 20% CP x 11% difference). Knowing whether this .53 pounds of protein is degraded in the rumen or small intestine will make a big difference in the type of protein (soybean meal versus blood meal for example) used to supplement the diet and ultimately how the cow milks.

RUP Test Available from Consortium Labs

The NIRS Forage and Feed Testing Consortium has the license to provide RUP analysis of legume and legume-grass silage. NIRS Consortium Laboratories have NIRS instruments standardized to a master instrument, which insures accuracy of analysis of the RUP in situ calibration. The following are NIRS Consortium members commercially testing forages which have the RUP calibration or are eligible to perform the test. (Bold Faced Labs Have Test Available at this printing):

Þ AgSource Soil and Forage Laboratory, Bonduel, WI, 715-758-2178;

Þ Commercial Testing Laboratory, Colfax, WI, 715-962-3121;

Þ Dairyland Laboratories, Arcadia, WI, 608-323-2123;

Þ Kent Feeds, Inc. Muscatine, IA, 319-264-4607;

Þ Michigan Department of Agriculture, East Lansing, MI, 517-337-5072;

Þ Oklahoma State University, Stillwater, OK, 405-744-7771;

Þ Pennfield Corporation-Feed Labs, Lancaster, PA, 717-295-8747;

Þ Peterson Laboratories, Inc., Hutchinson, KS, 316-665-5661;

Þ Servi-Tech Laboratories, Hastings, NE, 402-463-3522;

Þ Stearns DHIA Central Laboratory, Sauke Centre, MN, 320-352-2028;

Þ University of Nebraska, Lincoln, NE, 402-472-1571;

Þ Ward Laboratories, Inc., Kearney, NE, 308-234-2418; and

Þ Wisconsin Soil & Forage Analysis Laboratory, Marshfield, WI, 715-387-2523

WISCONSIN FORAGE COUNCIL

TWENTY THIRD ANNUAL FORAGE SYMPOSIUM AND MEETING

JANUARY 26 AND 27, 1999

PAPER VALLEY HOTEL & CONVENTION CENTER - APPLETON, WISCONSIN

920-733-8000 or 1-800-242-3499

Tuesday, January 26

8:00		Registration - Coffee/Milk
		Phosphorus Management on Dairy Farms
9:00		The Need for Regulating Nutrients - Joe Tregoning
9:30		How Much Phosphorus Do Dairy Cows Need? - Larry Satter
10:00		How Much Phosphorus Do Crops Need? - Keith Kelling
10:40		Survey Results of Forage Nutrient Management of MN Farms - Mike Russelle
11:10		Managing a Phosphorus Budget on Your Farm - Fred Madison
11:35		Reducing Phosphorus Risk with Management - Kevin Erb
12:00		Lunch & WFC Annual Meeting
	Silage Making and Feeding
1:30	Feeding Processed/Unprocessed Corn Silage Recent Research - Randy Shaver
2:10	How Well are Bunker Silos Packed - Brian Holmes
	Balancing Use of Corn Silage and Alfalfa In Dairy Rations
3:00	Nutritional Consideration - Randy Shaver
3:45	Economic Considerations - Gary Frank
4:30	End of Program
5:00	Social Hour - Exhibit Area
6:00	Awards Banquet

Wednesday, January 27

7:00		Continental Breakfast in Exhibit Area
8:00		Breakout Sessions
*Session A: Pest Management in Alfalfa*
	Potato Leaf Hopper - Mark McCaslin
	New Diseases - Aphanomyces 2/Mycoplasma - Rick Peters
	Leaf Miner - Brian Jensen
*Session B: Feeding Forages*
	Variability of Bypass Protein in Forages - Pat Hoffman
	Digestion Kinetics of Forages - Dave Combs
*Session C: Pasture Fertilization*
	Roundtable Farmers - Keith Kelling & Mike Russelle
*Session D: Pasture Management*
	Supplementation on Pasture - Dan Undersander
	Ryegrass Overseeding on Pasture - Dan Undersander
	Pasture Yield Estimation - Dennis Cosgrove
9:20	Repeat Sessions A, B, C and D
10:40	Repeat Sessions A, B, C and D
11:45	Lunch
1:00	Economics of Silo Tubes - Gary Frank
1:30	Farmers Doing Contract Feeding - Farmer Panel
2:45	Using Custom Harvesting on Our Farm - Farmer Panel

---------------"---------------"---------------"---------------"---------------"---------------"-------------

REGISTRATION FOR WISCONSIN FORAGE COUNCIL SYMPOSIUM 1999

Name_________________________________________________________________________

Farm Name or Company Name_____________________________________________________

Address_______________________________________________Phone____________________

City__________________________State______Zip____________County__________________

Advance Registration by 1/15			At Door
		Member	Member	Non- Member	Total
2-day Registration (banquet included)*		$70.00	$75.00	$80.00	$_______
2-day Registration for 2^nd Registration from same farm—spouse, child, partner—(banquet included)*		60.00	65.00	70.00	$_______
1-day Tuesday Only Registration (banquet not included)*		45.00	50.00	55.00	$_______
1-day Wednesday Only Registration (banquet not included)*		45.00	50.00	55.00	$_______
Banquet 1/26		15.00	15.00	15.00	$_______
	* Includes proceedings, program, coffee breaks, lunches and continental breakfast
Membership for 1999
Membership in Wisconsin Forage Council				$25.00	$________
Membership in American Forage and Grassland Association				10.00	$________
			TOTAL ENCLOSED		$________

Note: Registration is required for all events including the Trade Show

Please return with your remittance by January 15 to:

Wisconsin Forage Council

813 W. Lexington Pkwy, DeForest, WI 53532

Buying Hay

UPCOMING EVENTS
January 26 & 27, 1999	Wisconsin Forage Council Symposium - Paper Valley Hotel - Appleton, WI
February 10 & 11, 1999	Minnesota Forage Conference - Kahler Inn - Rochester, MN
February 21-26, 1999	American Forage and Grassland Council Meeting - Omaha, NE

IN THIS ISSUE
Pages 2-4	Kura Clover: A Promising Pasture Legume for Wisconsin
Pages 4-6	A New, Improved Test for Ruminal Bypass Protein of Legume & Legume-grass Silages
Page 7	WFC 23^rd Annual Forage Symposium Agenda & Registration Form
Page 8	Buying Hay

By: Ken Albrecht, UW-Madison

A New, Improved Test for Ruminal Bypass Protein

of Legume and Legume-grass Silages

New RUP Test

Ranges of RUP in Forages

RUP Test Available from Consortium Labs

Þ AgSource Soil and Forage Laboratory, Bonduel, WI, 715-758-2178;

Þ Wisconsin Soil & Forage Analysis Laboratory, Marshfield, WI, 715-387-2523