Duration: 10/01/1999 to 09/30/2004

Administrative Advisor(s):

NIFA Reps:

Non-Technical Summary

Statement of Issues and Justification

Profitability and competitiveness of the beef industry depend on its ability to control costs per unit of output. Production costs for the cow/calf sector of the beef industry are high. One problem is that forage quality and nutrient requirements of beef cattle are often not synchronized thus requiring the feeding of supplements and harvested forages to compensate for low forage quality. Another challenge is managing the seasonal variability in the amount and nutritional quality of the forage supply The result is that harvested forages and supplements are the largest component of total costs. Systems for beef production that make more effective use of standing forages by grazing should improve both the profitability and sustainability of the industry.

JUSTIFICATION:

The states of Missouri, Iowa, Nebraska and Kansas contain over 19% of the nation's beef cow herd In add-on these states annually finish about 12 million head of cattle, or nearly 43% of the nation s total The four states also contain 57.2 million acres of pasture and range (includes crop land grazed), which is about 38% of their combined farmland acres. The four states also produce over 23 million tons of hay. Corn and sorghum cover 28.9 million acres, which is critical resource for aftermath grazing.

Because of the needs for a variety of local support industries, cattle production has multiplier effects of nearly 3 and 6 times on the gross and net incomes of localities over the receipts of the cattle. As a result, cattle production is seen as an economic asset in support of the life in rural communities. Furthermore, because cattle production promotes incorporation of forages that are associated with reduced soil erosion and pesticide use, properly managed cattle production may be associated with improved environmental quality particularly on marginal lands by governmental agencies and the public itself. Unfortunately, forage management is commonly the weakest component of beef cattle operations, thereby limiting enterprise profit and promoting other less environmentally desirable farming practices.

Many studies have documented the large proportion of costs in the beef cow system that comes from harvested and purchased feeds (Strohbehn, 1990; Rasby et al., 1989; Economic Research Service Rural Economy Div., 1995). In the states of Missouri, Iowa, Nebraska and Kansas, most of these costs are incurred when harvested forages and/or protein supplements are fed to cattle during periods when dormant forage is either in short supply or of poor quality Because these costs often account for one-third or more of the total, it seems logical that a major reduction in harvested and purchased feed could enhance profitability of the cow-calf system. Cost reductions must be considered simultaneously with impacts on cattle and range/pasture production. Reducing production relatively more than reducing costs could lead to reduced profitability. Therefore, the goal is to reduce costs while maintaining or enhancing forage and animal production.

Preliminary work shows that it is not unreasonable to expect cost reductions of $40 to $50/cow from some of the methods proposed to extend grazing. These cost reductions can be made without significant reductions in production. Producer adoption of improved grazing systems across the four states, which contain about 5 million beef cows, could amount to significant savings. A savings of only $40/cow translates into a potential cost reductions of $100 million if only half the producers adopt these practices.

Our long-term goal is to produce nutritious and palatable beef with systems that optimize profitability and maintain environmental quality by improving the amount and efficiency of grazing. It is our hypothesis that increasing the proportion of feed harvested by the animals will lead to improved sustainability and profitability of the beef industry. In order to develop and test appropriate forage-beef production systems, several disciplines must contribute to this research project. Designing proper grazing systems for beef production requires examination of not only the animal and plant components of the systems, but also the interface between the two. The resulting production output must then be evaluated in terms of sustainability, profitability and risk. This project proposes efforts in each of these components, including the development of computer software to assist producers with forage-beef system management decisions.

The elemental component of the project is that of "extended grazing," i.e., supplying more of an animal's annual nutrient requirements through grazing. This project will identify and test alternative systems of beef cattle production that can better utilize standing forages not only during spring and summer, but during fall and winter as well. Supporting the development of improved forage systems for grazing, the proposed project includes research dealing with the evaluation of alternative forage grasses and legumes for extended grazing systems. Extended grazing systems are limited by the ability of pastures and rangelands to produce sufficient quantities of quality feed during various periods of the year. Thus evaluating alternative forage legume species is an important way to improve grazing systems for beef cattle. While this part of the project will examine several forage legume species, the new rhizomatous birds foot trefoil (RBFT) will serve as an initial focus point. This plant appears to have great promise as a high quality yet persistent legume for grazing situations. Evaluation of RBFT across the four states is needed to test its role as a new forage legume that may help improve grazing livestock performance.

There are several ways to extend the grazing season. Grazing can be extended by adjusting the physiological stage of cattle to better match forage nutrient content, adjusting the forage base to meet high nutrient needs of cattle, or a combination of both. Cattle can be matched to the forage by synchronizing increased nutrient requirements for lactation and gestation with increased nutrients in immature forages. Synchrony between forage growth and lactation can be accomplished by manipulation of calving and weaning dates. Synchronizing the high nutrient requirement phases of cows with high nutrient densities in forage may improve profitability. The production levels of cows and the chosen marketing method for calves have major impacts on overall profitability of the systems, so they must be evaluated as part of the systems. For example, alternative calving and weaning dates will be helpful to the evolution of branded beef programs that need a year-round supply of beef.

In addition to adjusting animal management, the efficiency and length of the grazing season may be improved through consideration of available forages. During spring and early summer, the cool-season grass species common in Midwest pastures are highly productive and nutritious. However, during mid-summer, forage production by the cool-season grass species is generally poor. During this period, the incorporation of legume or warm-season grass species may increase the uniformity of the forage supply and, therefore, animal production. Some common approaches for extending grazing later into the fall and winter in the region include grazing standing native range or pastures containing stockpiled cool-season forages Many beef producers in these four states also have crop production enterprises that provide opportunities for grazing crop residues to lower winter feed costs. The likelihood of finding beef animals and crops together on the same farm increases on land capability classes 3 and 4 compared to prime farmland. Because erosion potential also increases on these higher land capability classes, the use of cover crops for the dual purposes of forage grazing and erosion protection is proposed. Crop residues have been primarily considered as maintenance feed for brood cows. The incorporation of cover crops into the system can provide adequate forage quality for young, growing stock, allowing the farm greater flexibility in stocking decisions. Which method is chosen depends on the soils and climatic area in which a producer is located as well as other resources available. The levels of risk and its management are expected to differ among the systems. Through a regional project, we can test these concepts under wide variations in climatic conditions and forage resources, which will aid in risk assessment and management.

Because of the low forage production cool-season grasses and the low nutritive value of warm-season grasses during mid-summer, productivity of animals grazing these grasses may be limited during this period. Because of their uniform productivity and high nutritional value throughout summer, as well as their ability to fix nitrogen in the soil, legume forage species are valuable components of summer grazing systems in the upper Midwest. Legumes that have been commonly included in Midwest pastures include red clover, white clover alfalfa. Unfortunately, most of these legumes do not persist as long-lived perennials in grazed pastures. As a biennial red clover persists only 2-3 years in a pasture unless a favorable year permits bee pollination and fertile seed development. White clover persists in a pasture longer than red clover, but it tends to "die back" in hot, dry summers. Alfalfa, including some hybrids selected for grazing tolerance, generally does not persist long in most grazed pastures. Alfalfa is susceptible to weevils, leaf hoppers, various diseases, low fertility, waterlogged soil and cold winters. Most of these alfalfa stresses can be overcome with fertility programs and pesticides, but these practices may not be environmentally nor economically sustainable. Temporal and spatial ecological management practices like rotationa1 grazing may be used to increase persistence of alfalfa and other legumes.

A new forage hybrid, rhizomatous birdsfoot trefoil (RBFT), has been developed that may address many of the shortcomings of other legumes. According to preliminary data from the University of Missouri, the rhizomatous hybrids are not highly nutritional, but are also more persistent than standard birdsfoot trefoil. Data suggest that rhizomatous hybrids have improved persistence because their rhizomes allow stands to persist longer and thicken as individual crowns decompose. In addition, recent data indicate that rhizomatous hybrids have increased levels of chitinase, an antifungal hydrolase associated with disease resistance in many crops.

Initial studies conducted in the greenhouse, laboratory, and small plots indicate that this new crop has excellent potential for pastures in the four-state region. While initial studies are important and will remain important to answering specific component objectives, they do not answer the necessary applied questions that deal with agronomic use and animal performance. Evaluation of RBFT in this project will take on a systems context, using the specific component data but expanding the assessment of RBFT to its role in improved grazing systems for beef production. Similar to RBFT, kura clover is a legume species that also reproduces by rhizomes and seems quite persistent under grazing. Kura clover and RBFT will be compared to other legumes under various grazing systems as part of this project.

The ability to predict forage intake is essential to the development of management systems that optimize grazing efficiency, predict grazing animal performance and develop balanced supplementation regimes for grazing animals. At low forage allowances, forage intake seems related to the height and density of forage because of their effects on limiting animal bite size. Due to the varying relationships between sward height and forage density across different forage species, the coefficients explaining this relationship vary among different forages. If forage allowance is not limiting, forage intake is likely related to the volume occupied by the forage structure in the ruminant stomach.

The relationship between the amount of lignin and the amount of cell wall that is truly indigestible (iNDF) is relatively constant among many species. Because this indigestible cell wall occupies volume until removed from the rumen by passage to the lower gastrointestinal tract, it should be highly related to forage intake across species. Previous studies with different forage species have shown relatively consistent consumption and excretion of iNDF, implying the possibility that this forage component could be a predictor of intake of animals fed or grazing mixed species forages.

While iNDF shows promise as a predictor of forage intake across species, the stability of the relationship of iNDF concentration and intake needs to be further quantified in different cool- and warm-season grass and legume species. Furthermore, if iNDF is to be useful in predicting forage intake by grazing animals, coefficients weighting the relationships of sward physical characteristics and iNDF concentrations to forage intake, and for predicting the concentration of iNDF in forage selected by grazing animals from sward properties, must be established. Also, because the composition of pasture forages changes throughout the grazing season and decisions related to grazing management are instantaneous, rapid and accurate methods of determination are needed. Finally, because iNDF may control animal performance, understanding its physicochemical structure may be used to develop processes to improve the utilization of forages by ruminant animals.

Management decisions related to forage-beef cattle production systems are extremely difficult, if not formidable, for cattle producers. The difficulty arises from the inherent complexity of the plant-animal system which challenges the producer with many different, often interrelated, factors. Thus, it is difficult for producers to evaluate their system or to evaluate potential changes designed to improve their system. Such evaluations are critical, however, because of the profound impact that individual management decisions may have on cattle production. A computer program designed to evaluate forage-beef cattle systems would help producers make more informed management decisions. Computer programs can be used to integrate various components of a complex production system in order to evaluate or simulate the effects of various management decisions on the system. There are a few forage management programs available in the United States; however, the wide-spread use and acceptance of these programs is low because of their limited overall scope, relevance user friendliness, and flexibility. Development of forage-beef decision support software in this project will enhance the ability of producers to evaluate and improve their own grazing systems.

A regional approach to addressing the issue of improving grazing systems for beef cattle production offers major advantages. The four states have a wide variation in climate and resources. Nebraska and Kansas areas that are parts of the Great Plains and are semi-arid in nature. Some of the area is characterized by native, warm-season grasses. Eastern parts of Nebraska and Kansas and Missouri and Iowa contain primarily cool-season grass interspersed among irrigated and dryland crops. Annual precipitation in these four states ranges from about 15 inches in western Nebraska to over 39 inches in Missouri. Thus, hypotheses about appropriate systems, iNDF role in intake control across alternative forage species, and RBFT adaptation can be tested under a wide range of resource and climatic conditions, which should make the results applicable to an even larger part of the nation.

Coordinating the personnel and other search resources across the four states as they address these issues allows for expansion of ideas and hypothesis testing while at the same time reducing the collective costs of performing the work. Expertise will be shared across university and state lines, reducing duplication of effort and enhancing what any single group could accomplish. Faculty in the states of Missouri. Iowa, Nebraska, and Kansas have already begun cooperative projects dealing with many of these areas, and have started a regular series of bi-annual meetings in order to coordinate projects, share information, and develop ideas for future research studies. Administrators of agricultural programs for these states have indicated a willingness to support this collaborative approach. Cooperating faculty will also use this collaborative association as a base to strengthen competitive grant proposals to funding sources outside the universities.

The proposed project is complementary to the NC-157 regional project on Crop and Ruminant Systems to Conserve Midwestern Unglaciated Soils and Water Quality. The NC-157 project is focused on developing alternative forage-grain-cattle production systems unglaciated soils in the upper Mississippi River valley and includes participation from IA, IL. IN, MN, and WI. While the proposed project shares the common objective of improving forage-based cattle production systems, the geographical region of emphasis is different. The approaches used by the two projects will necessarily differ because of differences in soils and climate between the regions. We will closely monitor the activities of NC-157 to insure that our efforts remain complementary and may request a joint meeting at a future date.

Related, Current and Previous Work

The current and previous work related to extended grazing systems divides into three major categories that are not totally independent but reflect a degree of emphasis. First are studies that extend grazing by adjusting the cow's physiological state to the forage resources of a geographical area e.g., perennial grasses and crop residues. Second, other studies extend grazing by utilizing complementary forages, e.g., annual gram crops, introduced cool-season grassland legumes. Studies evaluating some aspect of the economic consequences of various systems, including risk analysis, make up the third category. Intermingled within each category are studies that either emphasize impacts on beef cattle production or the forage resource. Occasionally studies have looked at both aspects.

The potential importance of this project can best be understood by examining results of some analyses that have looked at the economics of beef cow-calf systems. Several studies have shown that feed costs often account for 40 to 50% of total costs for a beef cow operation, and that there is a large variation in total costs among producers (Strohbehn, 1990; Rasby et al., 1989; Economic Research Service, Rural Economy Div., 1995). The proportion of harvested and grazed forages is also important to producers with stocker-grower enterprises. Producers who rely more heavily on grazed forages and, consequently, who incur lower expenditures for off-farm purchases of supplements had significantly higher profits (Klopfenstein, 1991). Rasby et al. (1989) also reported that the low-cost producers in an Integrated Resource Management project were able to make use of less expensive, low-quality forages. Several studies have found that extending grazing either of pasture forages or crop aftermath improves the profitability of cow-calf systems (Adams et al., 1994; Klopfenstein, 1991; Strohbehn, 1990). Such extended grazing systems reduced the amount of mechanically harvested forage fed without reducing productivity.

Adjusting cattle to the forages.

Different forages have different rates and patterns of growth. Forage quality or feed value also changes throughout the growing season according to temperature, moisture, and plant maturity. As grazing programs are developed, seasonal distribution of forage growth and forage availability and quality should be balanced with the nutritional demands of livestock. Livestock production will be optimized only when both quantity and quality of forage are adequate. Guidelines have been developed to fit forages of different primary seasons of growth into season- long grazing programs based on their primary period of production and quality (Waller et al., 1986).

Studies detailing the seasonal variability of nutrients available to cattle from range forage have been conducted in the northern Great Plains (Adams and Short, 1988; Adams et al., 1989; Adams et al., 1993) and Nebraska (Powell et al., 1981; Streeter et al., 1967; Lardy et al., 1997). The highest potential from range forage in the Nebraska Sandhills for beef production is during June, July and August. During the part of the year when the nutrient requirements for maintenance and milk production by the cow exceed what the forage can supply, cows lose weight and condition (Adams et al., 1989; Adams et al., 1993). Thin cows at calving breed late in a controlled breeding season or do not breed at all, and represent the single most important factor affecting net calf crop in beef herds (Dziuk and Bellows, 1983). Reproduction is more important than genetic growth rate or carcass merit on net returns to the beef producer (Melton, 1995). Many producers feed hay and/or other purchased feeds to cows during various times of the year to compensate for poor forage quality and to maintain pregnancy rates; however, this practice is expensive. Adams et al. (1996) suggested that the cow is matched best with range forage when peak lactation occurs near the highest density of protein in the forage. Management practices such as weaning date, calving date, supplementation, and grazing of complementary and stockpiled forages can extend grazing and reduce the amount of harvested feeds fed to cattle (Adams and Short, 1988; Adams et al., 1994; Hitz and Russell, 1998).

There is evidence that some producers are adjusting calving and breeding dates to better match their forage resources and to extend grazing seasons (Clark and Coady, 1992; Schafer, 1992) The research community, however, has been slow to develop and test innovative methods or systems of balancing forage supply and demand. Recent studies in Nebraska and other western Great Plain states demonstrate that calving late in the spring reduces hay fed and improves profitability (Roath, 1985; Deutscher et al., 1991; Smith et al., 1995; Clark et al., 1997, May et al., 1998).

Iowa and Missouri also have studies underway that are Bating alternate calving dates as means of improving the synchrony between beef cattle requirements and nutrient densities of forages. Research in eastern Nebraska (Story, 1998) and the Nebraska Sandhills (Adams et al, 1998) is investing the effect of weaning date on animal production and overal1 profitability. The interacting effects of marketing date and cow body condition are also being analyzed.

Researchers in Tennessee (McBride et al., 1991) and Louisiana (Bagley et al 1987) found that fall calving systems were generally more profitable than spring calving systems. Differences in the historic price cycle tend to favor fall calving, and helps explain why it may be more profitable than spring calving. In Nebraska, Adams et al. (1994) showed that a system utilizing spring grazing of subirrigated meadows and grazing of meadows in winter dominated other traditional systems for profitability. The study used stochastic dominance procedures to account for risk and to rank the alternate systems. DSouza et al. (1990) reported similar results for a grazing study in West Virginia. They concluded that grazing meadows in the spring and fall coupled with one haying after spring grazing was the economic optimal choice.

Bellido et al. (1981) studied the effects of date of calving and supplementation on productivity of range cows in New Mexico. Weaning weights of calves adjusted to a 220 day weigh were not significantly different between the early bred (April 15 to July 1) and late bred (June 1 to September 1) cows. Cows receiving supplement (.45 kg of pelleted cottonseed meal every three days) produced calves that were heavier at weaning and gained more from birth were profitable or the effects of market timing.

Most of the calves in the northern states are born in early spring. For a production system to incorporate a summer grazing program, calves must be reared through the winter months following fall weaning. To fully benefit from summer forages, compensatory grow can be used to increase gains. The relationship between the amounts of winter gain and summer gain has been shown to be highly variable, depending upon the animal status and diet during realimentation. Several studies indicate .8 lb./d reduction in grazing gain in the summer for every pound of winter gain (Wanyoike and Holmes; 1981; Lawrence and Pearce' 1964; and McCarrick et al., 1963). The percentage compensation reported in each of these studies varied depending on the relative lengths of the winter and pasture periods. Feedlot finishing performance also can be affected by previous nutrition, particularly as it relates to grazing programs. Finishing rate of gain was improved for heifers wintered on cornstalks and summered on grass compared to those finished immediately following a corn silage feeding period (Mader et al, 1989). In contrast, average daily gain and feed efficiency of beef cattle in the finishing phase were not positively influenced by earlier summer grazing periods (White et al., 1987; Gill et al 1992).

Adjusting forages to the cattle.

Complementary forages are used in conjunction with a primary forage resource such as rangeland to make a more complete forage program than when either is used alone. Forage programs are enhanced by adding forage sources at times when quantity and/or quality of the primary forage limits livestock production. To extend or prolong the grazing season and possibly work toward a year-around grazing program, several different types of forage plants are needed. Beef cattle production in the Great Plains relies heavily on rangeland as a forage source. The impact of using complementary forages with range has been documented (Lodge, 1963; Smoliak, 1968; Moore, 1970; Anderson and Jemstedt, 1971; Alien, 1972; McIlvain and Shoop, 1973; Ford et al., 1986; Hart et al., 1988); however, literature that provides comparative data among systems that are relevant to the Great Plains is limited (Nichols, 1989; Nichols et al., 1993; Smart et al., 1994). Complementary forages in the central and eastern Great Plains include (1) perennial, cool-season grasses, (2) annual, winter small grains, (3) perennial, warm-season grasses, (4) annual, warm-season grasses such as pearl millet, sudangrass, and corn, (5) crop residues, and (6) high quality hay.

Complementary forage systems have the potential to increase production per unit of land, improve animal performance, provide an alternative to harvested forages, and increase forage availability during drought or dormant periods (Launchbaugh, 1987; Nichols, 1989). If production costs are not reduced or net returns enhanced, increased production and improved forage quality are probably of little interest. Grazing complementary forages usually is less expensive than feeding hay or silage. Estimates indicate that feeding beef cattle harvested forages costs about $0.50 more per head per day than allowing them to harvest their own feed by grazing. Thus, to minimize production costs, successful complementary forage systems must include an appropriate group of forages as well as the most efficient harvest/grazing strategy.

Extensive research has been conducted that adjusts forage to the beef cattle system (Spielman and Shane, 1985; Adams et al., 1989; Bagley et al., 1987; Ethridge et al., 1987; Hart et al., 1988). Hitz and Russell (1998) have researched the stockpiling of perennial forages and the use of corn residue to enhance the opportunities for winter grazing of spring calving cows in Iowa. They found that grazing stockpiled tall fescue-alfalfa and smooth bromegrass-red clover and corn crop residue reduced hay DM needed by over 1 ton/cow for the stockpiled systems and by about 1400 lb for corn stalks compared to a dry lot system. They also found that the decline in IVOMD and CP content of the two stockpiled forages and corn residue was at similar rates over the winter. Cows grazing the stockpiled forages and corn residue maintained body weight and condition score. The study did not analyze the relative economic aspects of the alternate systems.

Researchers at Iowa State University have established a year-around grazing system and are comparing it to a system where cows are drylotted during the winter and spring periods (Hersom et al., 1998). Year-around systems utilized corn residues and stockpiled tall fescue-red clover or smooth bromegrass-red clover. They have found that the year-round grazing system required about 6300 lb less hay (dry matter) compared to the drylot system with little difference in animal performance. There is a need to subject this research to an economic and risk analysis. In addition, similar systems need to be established and tested under other environmental and resource situations.

Winter annual forages could also be used in a winter feeding program. Winter annuals have at least two major benefits. First, their forage quality could be higher than stockpiled grass or low quality haw (Rao and Horn, 1986; Jung and Shaffer, 1993). Lactating cows or rapidly growing stock might perform satisfactorily on these pastures with little or no supplementation. Second, winter annuals could serve as cover crops on row-crop farms. Incorporating cover crops into row-crop systems can reduce soil erosion, increase crop yields, improve soil organic matter, and decrease sedimentation of streams (Zhu, et al., 1989; Keeling, 1996). But, research examining the use of winter annuals for the dual purposes of winter grazing and cover crops is lacking. Potential benefits of using winter annuals for both grazing and soil cover include more efficient land use, improved manure distribution over the whole farm, reduced fertilizer inputs for subsequent grain crops, improved soil tilth, less soil erosion, low-cost forage production, and inexpensive winter grazing. Although many potential benefits exist, several management problems need to be addressed. Producers need practical information on which species are most suitable for grazing, forage production periods, regrowth potential, forage quality, adaptation to different climates and soils, grazing management, and stocking rates.

Profitable livestock production is often limited by availability of nutritional pasture during the summer. Several warm-season, perennial and annual grasses have been identified for summer use; however, forage quality of these grasses by midsummer is low in most cases (Waller et al., 1986). Grazing strategies, i.e., management-intensive grazing, and forage legumes have been investigated as means of improving forage quality of warm-season pasture. Grazing strategies that improve grazing distribution and utilization potentially improve forage quality by maintaining a high proportion of the stand in a vegetative stage during much of the growing season (Volesky, 1994). Legumes that actively grow during the summer provide high quality forage; however most commonly-recommended legumes, e.g., red clover and alfalfa, do not persist well under grazing. Birdsfoot trefoil has shown potential as a forage legume in the central and upper Midwest region. In eastern Kansas, birdsfoot trefoil alone and mixed with grasses yielded and persisted well compared to alfalfa, red clover and crownvetch (Posler et al., 1986). Trefoil produced relatively high yields of forage with superior quality compared to other legumes when interseeded into established tall fescue (Posler and Frnasen, 1978). Several cultivars of birdsfoot trefoil were high-yielding and persistent for five years in pure stands at two eastern Kansas locations (Posler et al., 1985). Forage yields of trefoil for a three-year period in claypan soils of southeastern Kansas that tested in the low category for P and/or K were equal to those of alfalfa (Moyer et al., 1994). The new RBFT hybrid shows even more promise as a forage legume than common hybrids because of its ability to spread by rhizomes and thus have greater persistence in grazing situations. Similarly, kura clover (Albrecht et al., 1998) and grazing-tolerant alfalfa hybrids also have potential to improve the long-term uniformity of the forage supply. Therefore, as part of the development and testing of improved grazing systems for livestock, this project will include the evaluation of the RBFT and other legumes in various grazing systems with different temporal and spatial environments.

See attached "Related, Current and Previous Work" for additional information.

Objectives

1. The overall objective is to develop and evaluate concepts and systems that increase the uniformity of the year-round forage supply and the efficacy of forage, animal and grazing management to improve the profitability of beef production. Specific objectives are to
   
2. To quantify production and economic impacts, including risk, of beef cow-calf systems that better match animal nutrient requirements to the quantity and nutritional value of the forage supply.
   
3. To improve the profitability and productivity of cow-calf systems by identifying alternative forage species and grazing management to extend me length of the grazing season.
   
4. Develop strategies for using forage legumes to improve the agronomic, animal performance, environmental, and economic characteristics of forage-beef systems.
   
5. Develop a systems-based educational program on integrated forage/cattle management systems for cow-calf producers in the four-state region.
   
6. 
   

Methods

Researchers in participating states will form teams that cut across relevant disciplines. It is not expected that all states participate in all objectives. Once individual experiments are initiated, preliminary results will be available within a 3 to 5 year time frame. The link that ties these objectives together is the overall objective of improving grazing systems. The objectives to be addressed by each state are listed below. Objective 1:

A minimum of two forage-based cow-calf production systems will be evaluated at each of the participating stations. In the Nebraska Sandhills, cow herds calving in March and weaning in October, calving in June and weaning in January and managed in forage systems using minimal stored forage will be compared. A second study in Nebraska will compare a conventionally-managed herd and a low-input (e.g., minimum amounts of purchased feeds) herd, and evaluate optimal use of corn residues. It is expected that calves from the March and June calving systems in Nebraska will be born during the first year and each subsequent year of the project. In Missouri, cow herds calving in March and May with weaning at a comparable age and managed in forage systems using minimal stored forage will be compared. In Iowa, comparison will be made of cow herds calving in March or August, managed with either summer grazing-winter drylot hay feeding or a year-round grazing system with calves either finished at weaning or after a summer grazing interval. In the Missouri and Iowa studies calves from the alternative systems will be born at least one year after the project begins. For each study, relevant production data (e.g., weaning weights, body condition scores, and reproductive performance) will be collected for a minimum of three years after the first calves are born. Economic analysis of the systems will begin in the third year of the project and be completed by the end of the project. Production data will be incorporated into an economic evaluation that will consider seasonality of prices on the profitability of the systems. The economic analysis wil1 be he main performance measures of the alternative systems; however, production measures such as pounds of calf weaned per cow exposed, pregnancy rates, harvested and purchased feed fed will also be important measures of system performance. Kansas will develop a database for the forage quality characteristics of native rangelands in Kansas. Kansas will also lead the development of forage-beef system decision support software based upon the Forage Management and Utilization Program (FMUP) from Kansas State University and the KYBEEF program from the University of Kentucky. This software will estimate and compare to forage production and livestock demand across alternative grazing systems, integrating into the program forage species production system, and seasonal distributions suitable for the central and upper Midwest region

Objective 2:

Scientists in Nebraska, Iowa, and Missouri will continue to conduct component research to determine the interacting effects of calving dates, weaning dates, animal nutrition, and strategic use of complementary forages. Of particular interest will be the relationships among weaning date, dormant-season nutrient requirements of the cow, calf performance and reproductive performance of the cow. Kansas will evaluate wheat and crabgrass as parts of a double-crop system in conjunction with lespedeza.

Another aspect of the proposed research will be development of grazing strategies that lend themselves to the development of year-round grazing. In Nebraska different combinations of spring, summer and dormant-season grazing of Sandhills rangeland will be applied to determine the effect of multiple seasons of use on plant vigor and forage yield. Treatments will be applied at different stocking rates so that carrying capacity of the different grazing programs can be calculated. Diet quality and animal performance also will be measured in each of the seasons of treatment application.

Approximately 20 different winter annual forages (forages that also could be used as over crops) will be evaluated across the participating states. These crops include wheat, rye, triticale, annual ryegrass. hairy vetch, turnips, forage rape, bur clover, tyfon, kale stemless kale, swedes, Swiss chard, crimson clover and possibly a few others. These crops will be planted to maximize forage production during the January-March window. Forage yield will be measured on four different dates: December 15, January 15, February 15 and March 15 (+7 days). Plant height and ground cover will be recorded just prior to each harvest. Forages that exhibit regrowth will be harvested on successive dates in addition to harvesting uncut portions of the same plot. Sub-samples from each harvest will be retained for forage qualify analysis. Additionally, on January 1, February 1, and March 1, sub-samples will be taken from each plot to document any deterioration in forage quality between harvests. Quality measurements will include crude protein, acid detergent fiber and neutral detergent fiber. Forage quality will be predicted using near infrared reflectance spectroscopy (NIRS). Partial budgets examining the feasibility of using winter annual forages will be prepared. A sensitivity analysis examining the influence of cattle prices, forage production and hay prices will be used to partly determine the potential of winter annual forages.

In Iowa, kura clover will be planted as a permanent legume in a strip-cropping system with corn to be grazed with corn crop residues. Cows will graze corn stalks without or with stockpiled kura clover with the amounts of hay required to maintain cow body condition and forage yield and quality data recorded.

All trials associated with this objective will be established during the first year of this project. Where annual forages are used, they will be established at appropriate times during the first year of the project. Economic analysis of results will begin during the fourth year of the project and will be completed by the end of the fifth year. It is anticipated that graduate students will use parts of this objective for meeting their thesis or dissertation requirements. Successful completion of these students will be one of the quantifiable measures of performance.

In order to improve grazing management by adjusting forage allowance, development of improved methods of predicting forage intake are essential. To quantify the relationship of indigestible NDF with forage intake, different warm- season grass species, cool-season grass species, and legume species will be harvested as either green chop or hay at differing maturities at experiment station research farms in Iowa and Missouri. At these farms, forages will be individually fed ad libitum as 100% of the dietary dry matter and/or as fractional mixtures varying the indigestible NDF concentrations in intake experiments with cows or yearlings using switchback designs. Data recorded will include the indigestible NDF concentrations of forages and feces, dry matter intake and fecal excretion. Indigestible NDF concentration will be correlated to dry matter intake and the variation in the amounts of indigestible NDF consumed and excreted will be quantified both within and among forage species. In addition to analyzing these samples for indigestible NDF by gravimetric methods, samples will also be used to develop calibration curves for Near Infrared Reflectance spectroscopy.

To quantify the relationships between indigestible NDF and sward characteristics in predicting indigestible NDF concentration of selected forages and forage intake, summer and winter grazing experiments using pastures containing monocultures as well as mixed species swards containing warm-season grasses, cool-season grasses, legumes, and crop residues by different management systems and at different stocking rates will be conducted at experiment station research farms in Iowa, Nebraska, and Kansas. The variability in grazing systems and pasture species will provide the variability needed for predictive equations. In each of these experiments, samples of forages clipped from the pastures, forages selected by steers fitted with esophageal or ruminal cannulae, and feces excreted by grazing cattle will be collected. Samples will be analyzed for indigestible NDF concentration in Iowa. Single and multiple variable regression as well as neural network analysis will be used to relate indigestible NDF concentration of forage selected by grazing animals to the chemical composition of the forage including total NDF, acid detergent fiber, and acid detergent lignin, as well as to the physical properties of the sward including sward height, total and live forage mass, total and live forage allowance, and the botanical composition. To estimate forage intake in each of the grazing experiments, fecal output will be estimated by use of fecal collection bags in Nebraska and with the use of chromic oxide as an indigestible marker in Iowa and Kansas. DM intake will be calculated using the formula: DM intake = Fecal output/(l-Digestibility/100). Forage dry matter intakes and indigestible NDF concentrations of forages selected by cattle in the grazing experiments will be used to validate regressions determined in intake trials. Furthermore, forage dry matter intake will be related to the chemical composition of the selected forage and the physical properties of the sward by multiple regression and neural network analysis to broaden the applicability of predictions over the variety of conditions observed in Midwestern pastures.

To elucidate the role of indigestible NDF on forage intake and digestion, total and indigestible fiber from the forage samples collected in previous experiments will be separated, hydrolyzed, and solvent extracted. Carbohydrate and phenolic components will be quantified by gas chromatographic and high performance liquid chromatographic procedures in Missouri.

Objective 3:

Kansas will examine the ability of Steadfast (a cultivar of RBFT), a standard variety of birdsfoot trefoil, and five other legumes that are used in tall fescue pastures to compete in established endophyte-infected tall fescue. Plant counts would be made each of three years in mid-season (~July 1) and at the end of the season (December). Forage production and quality would be measured from three to four cuttings during the growing season. Grass and legume components would be subsampled individually and assayed for crude protein and NDF contents, then assays of composite forage from each plot would be used to estimate composition by species (Johnson et al., 1982).

Iowa and Missouri will participate in a series of small plot and pasture-scale trials to evaluate a variety of perennial and annual grasses and legumes The forages will be planted as monocultures or in mixtures with normal and endophyte-free cultivars of tall fescue. Yields and nutrient composition of forages will be measured at different periods of the year, and animal production from the pastures will be evaluated. Nebraska will be involved in related studies screening various legumes for establishment, persistence, payability, and forage quality characteristics in both monocultures and mixtures.

In Iowa, the Steadfast RBFT cultivar will be compared to Norcen birdsfoot trefoil, Kura clover and other legumes under a range of conditions. One is under continuous heavy grazing in essence a stress test to determine its survival under such conditions. The trial will be continuously stocked with beef cattle from mid-May through mid-September, keeping the forage to 5 cm or less. After three years of grazing are completed, surviving plants will be dug and used to develop an improved population. Three years of testing yields of various BFT cultivars will also be conducted. Iowa will also compare Steadfast to Norcen, the most commonly grown cultivar in Iowa, for persistence under extreme grazing pressure using sheep as the tool to provide close and heavy grazing. Reproductive problems in the sheep will be monitored to see if RBFT may affect breeding and gestating of sheep. Two on-farm tests of RBFT in small plots will compare Steadfast with four other cultivars under both clear seeding using a pre-emergent herbicide control and when seeded with a companion grass. Iowa will also conduct a breeding program to address the most obvious drawback of the Steadfast birdsfoot trefoil cultivar: low forage yield. Selection will be conducted within Steadfast for several traits: yield, semi-erect growth, freedom from diseases, and winter survival. In addition, a second population will be elected for extreme prostrateness, keeping other traits the same. The rationale for this population is to determine if the purported superior grazing tolerance of Steadfast is due to the prostrate growth, or whether higher yielding populations can be developed and retain grazing tolerance.

In Missouri, an experimental line of RBFT and "Norcen" BFT will be compared under grazing, both in pure stands and with "Phyter" endophyte-free tall fescue. Stands will be stocked with crossbred steers and evaluated under continuous grazing. At the end of three years, data will be summarized regarding stand density of trefoil in pure and mixed stands, forage quality and antiquality components of mixed and pure samples, animal gain (individual and gain/acre) over each treatment, and animal preferences. Missouri will also study RBFT and BFT in their ability to produce biochemical defense products, both as constitutive and elicited expression. The primary defense product studied will be chitinase, the fungal hydrolase associated with disease resistance in many other crops. In a series of greenhouse studies, chitinase expression will be studied as influenced by physiology such as germination and seedling development, as affected by genetic polymorphism, and as a response to abiotic and biotic stress.

The first two years of the project will be used to establish stands of RBFT and other legumes. Tests on these stands will then be conducted for the following three years. Upon completion of these experiments, forage and animal production data will be incorporated into economic models to determine the return on investment into legume incorporation for different beef production systems. Progress towards completion of this objective will be measured by periodic reporting of progress in legume establishment and evaluation during meetings of the research teams.

Objective 4:

We propose to build on the existing framework of the four-state cow-calf conference that has been conducted for several years in the region. Each year these workshops are held in one or more of the four states and are taught by a team of instructors from the four land-grant universities. Also in this region, Missouri has pioneered the use of three-day in-depth grazing management workshops. This approach has been a very successful avenue for producer education, resulting in a producer adoption rate for improved grazing management practices of nearly 90% (Gerrish, 1997). Combining the multi-day in-depth workshop on integrated forage and cattle management with the four-state cow-calf conference, we propose to develop multi-day total systems oriented workshops for forage-based beef production systems. These schools will not dwell on the standard management practices, but will stress the new technology derived from this research, including products (RBFT), procedures (iNDF) and management practices (winter feed, calving, etc.).

Measurement of Progress and Results

Outputs

Outcomes or Projected Impacts

• See attached "Outcomes"

Milestones

(0):0

Projected Participation

View Appendix E: Participation

Outreach Plan

Organization/Governance

The overall project will be managed by a Technical Committee made up of at least two representatives from each state. The technical committee members from a given state will each represent a different discipline. The major responsibility of the technical committee is to develop uniform research procedures to be followed by each state where the states are participating in common objectives. A chair and secretary will be elected by the technical committee. These two officers plus one other member of the technical committee will form the Executive Committee that will be responsible for conducting necessary business between meetings and close coordination with the administrative advisor. Subcommittees will be formed around each objective. These subcommittees will contain a member from each state participating in the objective. It will be the responsibility of the subcommittees to draft uniform research procedures by objective that will then be approved by the Technical Committee. The technical Committee will meet at least twice a year. The purpose of these meetings will be to coordinate project activities, review preliminary results, plan pursuant activities and organize competitive grant writing efforts based on project results and needs.

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Attachments

Land Grant Participating States/Institutions

IA, IL, KS, MO, NE, OH

Non Land Grant Participating States/Institutions