Duration: 10/01/2004 to 09/30/2009

Administrative Advisor(s):

NIFA Reps:

Non-Technical Summary

Statement of Issues and Justification

Forage-based beef cattle production is an important component of the economies and environmental quality of states in the North Central Region (NCR). Even though most feed units consumed by beef cattle are grazed forages, stored feeds are a major component of cattle diets during periods of the year when forage quantity and/or quality are limited. Cost of feeding stored feeds is a major constraint on the financial returns of beef cattle production. The primary purpose of this project is to optimize the amounts of dietary nutrients supplied by grazed forages for beef cattle throughout the year. The major factor limiting grazing in the NCR is the ability of pasture and rangeland to supply sufficient quantities of quality forage throughout the year. Forage availability and/or quality are restricted by the seasonality of the growth patterns of different forage species, drought risk during the growing season, weathering of standing forage and/or snow and ice cover of standing forage during winter. For sustainable systems, producers must use range and pasture forages efficiently without harming the long-term productivity of the base resource. Efficient use must include economic returns from the forage that are competitive with alternative uses, especially in parts of the NCR where grazing land values and rental rates have escalated. Productivity and profitability of beef cattle production can be improved if cost-effective strategies are developed that improve temporal uniformity of the nutrient supply for grazing cattle. Uniformity of the nutrient supply can be improved by identifying forage species and cultivars that complement productivity and nutritional value of common forage species on pasture and rangeland during the summer and/or winter. Inexpensive, strategic nutrient supplements, such as co-products from the grain processing industry, also can be used when resources and/or weather conditions limit pasture and range forage production and/or nutritional value. Alternatively, a cowherd can be managed so that nutrient demands can be synchronized with the forage supply. Nutrient requirements of beef cows are particularly sensitive to reproductive/lactation cycles that can be manipulated to better match the timing of forage production. Finally, for balancing cattle diets in the grazing systems of the NCR, the database of the 1996 Nutrient Requirements for Beef Cattle model (NCR, 1996) needs to be expanded to include the composition of forages in the NCR as affected by species, location, season, and grazing management. Improved models and decision support tools also are needed to aid producers in managing their forage resources.

Justification. Forage-based livestock production is a vital component of the agricultural economies of states in the NCR. This region possesses 33% of the nation's beef cow herd. The states of Kansas, Missouri, Nebraska, North Dakota and South Dakota alone have 8.234 million head of beef cows, which accounts for nearly 25% of beef and dairy cows; adding the two participating states of Iowa and Ohio brings that number to 10.39 million. The region finishes over 53% of cattle marketed for meat (NASS, 2003). Forages account for 80% of the feed units consumed by beef cattle and, therefore, represent an extremely important resource to the industry (Bula et al., 1981). Perennial forages occupy approximately 106 million acres or 31% of land classified as farmland in the NCR (USDA-NASS, 1997). Improving the quality and utilization of these forage resources would contribute significantly to the productivity and profitability of livestock production in the NCR.

Ethanol production from feed grains is a rapidly growing industry contributing to the economies of the NCR. Total ethanol production in the United States has more than doubled in the past 10 years and is expected to increase in the future. Approximately one-half of the 3.4 billion gallons of ethanol produced annually in the United States is produced in Iowa, Kansas, Missouri, Nebraska, and North Dakota. Including the amounts produced in South Dakota, Minnesota, and Illinois, this region accounts for 90% of U.S. ethanol production. Processing grain for ethanol also annually yields 10 million tons of the co-product, distillers grains. Other grain processing industries, such as wet processing of corn for fructose production, yield additional co-products like corn gluten feed. These co-products may serve as cost-effective nutrient supplements for cattle and other animals.

We hypothesize that the sustainability and profitability of the beef industry can be improved by increasing the proportion of total cattle feed that is harvested directly by grazing cattle and by balancing the diets of grazing cattle with low-cost supplements. Productivity of forage-livestock systems in the NCR is primarily limited by seasonality of forage growth. Throughout most of the NCR (east of 100W), pastures composed mainly of cool-season forage species are the predominant source of nutrients for grazing livestock. These pastures produce most of their growth in the spring and early summer. Consequently, the carrying capacity of these pastures is greatly reduced as the season progresses. Under typical management practices, much of the early growth is undergrazed in order to stockpile forage for use later in the season. A major problem with this management system is that as nongrazed forage is allowed to mature, its quality diminishes to very low levels. The energy value of cool-season grasses can change as much as 30% from the vegetative stage to maturity (Nelson and Moser, 1994). In the western area of the NCR, warm-season species predominate. While these species are most productive in mid-summer, forage in these rangelands may be of inadequate quantity and/or quality in early and late summer. Furthermore, the supply of forage with adequate nutritional quality for grazing in the NCR may be limiting during fall and winter when both cool- and warm-season species are dormant. Livestock growth rates and reproductive performance generally decline in response to these changes in seasonal forage availability and quality unless their diets are supplemented with additional nutrients.

Several different strategies have been previously evaluated for managing the seasonal distribution of forage production. Complementary grazing systems that rotate cattle among pastures consisting of forage species with differing patterns of seasonal growth and development have been used to improve the uniformity of the nutrient supply during the grazing season (Jung et al., 1985). These systems typically utilize cool-season grasses for spring and fall grazing and warm-season grasses for summer grazing. Selection of species for complementary grazing systems historically has been based upon seasonal biomass accumulation data with little regard to forage quality. The objective of such systems is to provide an adequate level of available forage throughout the grazing season. An even more effective approach would be to develop systems on the basis of available nutrients. In order to develop such systems, basic information on the growth, development, and nutritional composition of adapted species is required.

Although stockpiling forages during late summer and fall for use after the growing season is a common practice, surprisingly little documentation of the quality of various forages is available. Stockpiled forage quality studies conducted to date have two problems: 1) comparisons among species are difficult because no study has evaluated many different species simultaneously (and many common species have never been evaluated at all) and 2) virtually no comparisons of cultivars within species have been conducted. Given the large variations in biomass productivity and forage quality present among varieties, cultivar choice probably has an impact on stockpile quality.

Because of constraints on land, labor, equipment, and capital, some producers may be unable to grow complementary forage species for summer grazing or stockpile forage in late summer when a forage deficit often occurs. Furthermore, some roughages like stockpiled warm-season grasses or crop residues that are commonly used for winter grazing by beef cows in the NCR are inherently deficient in protein, phosphorus (P), and other nutrients. Also, even with excellent management of productive, highly nutritious species, grazing systems are susceptible to the risks of drought in the summer and snow and ice cover in the winter. Dependent on price, use of supplemental feeds may be a cost-effective risk management strategy if the amounts and/or nutritional quality of forages are inadequate. Because of the expansion of the grain processing industries, co-products like distillers grains or gluten feed may be purchased at a price that is competitive with corn on a net energy basis and, with further growth of the industry, will likely be less expensive in the future. Because the co-products generally have high concentrations of protein and P, their composition complements those of mature forages that are deficient in these nutrients. As these nutrient deficiencies occur at different times of the year in different forages, evaluating co-products of grain processing as supplements to indigenous forages in each state of the NCR will prove valuable.

Cow nutrient requirements vary with physiological stage; therefore, grazing may be extended by adjusting the physiological stage of cattle to match the supply of nutrients available from forages and/or supplements (Adams et al., 2001). Through manipulation of calving and weaning dates, the nutrient requirements of cattle can be synchronized to match the forage nutrient supply as affected by productivity and maturity. Altering calving and weaning dates as well as altering the method of marketing calves may affect the profitability and risk of the systems (Carriker et al., 2001). Furthermore, the optimum method depends on the soils and climatic area in which a producer is located as well as other resources available. 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.

The ability to balance the nutrient content of the diets of grazing cattle with tools like the NRC computer model of the Nutrient Requirements of Beef Cattle (NRC, 1996) has improved because knowledge of the metabolism and requirements of nutrients in beef cattle has increased. Limited knowledge of the composition of different forages as affected by species, location, season, and grazing management, however, limits the abilities of cattle producers to implement diet balancing to improve nutrient utilization and reduce nutrient excretion by grazing cattle. This deficiency is further complicated by the lack of knowledge relative to the effects of selective grazing on nutrient intake. There is the need to develop a database on the composition of forage consumed by grazing cattle as affected by forage selection, location, season, and grazing management.

Well-planned and coordinated educational programming is needed to effectively transfer the information obtained from research evaluating the use of alternative forages and/or nutritional supplementation. Systems-based educational programs are needed for cattle producers that integrate forage, supplementation, and cattle management strategies in profitable systems with minimal economic and environmental risk.

Several disciplines must contribute to this research project to develop and test appropriate forage-beef production systems. 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 by faculty with expertise in forage plant breeding and physiology; pasture and range ecology; beef cattle nutrition, physiology, and management; and agricultural economics from the participating stations. Furthermore, an outreach program is planned to train producers in the use of this information to improve the profitability and environmental quality of their enterprises. Incorporating the results of the forage analyses into the beef cattle NRC model will be an important component of this educational effort. Each station participating has the research farm and laboratory facilities to conduct the proposed research and the faculties involved in this project are experienced in conducting such research and educational efforts.

A regional approach to addressing the issue of improving grazing systems for beef cattle production offers major advantages. The seven states participating in this project have a wide variation in climate and resources. Kansas, Nebraska and North Dakota offer areas that are parts of the Great Plains and are semi-arid in nature, growing native, warm-season grasses. Eastern parts of Kansas, Nebraska and North Dakota contain primarily cool-season grasses interspersed among irrigated and dryland crops. Cropland and cool-season grass pastures predominate in varying proportions in different regions of Iowa, Missouri, Ohio and Pennsylvania. Annual precipitation in these seven states ranges from about 15 inches in western North Dakota to over 41 inches in Pennsylvania. Thus, our hypotheses can be tested under a wide range of resource and climatic conditions, making results applicable to a larger part of the nation.

Results of the proposed research and outreach program will improve the profitability and reduce the economic and environmental risks of grazing-based beef cattle production in the NCR by: 1) increasing the uniformity of nutrient supply consumed by grazing cattle through use of alternative forages or low-cost supplements at times when the quantity and/or nutritional value of conventional forages are limiting and 2) providing producers with the tools and skills to better balance the diets of grazing cattle in the NCR. Data from applications of Integrated Resource Management-Standardized Performance Analysis show a wide variation in the economic and financial performance of cowherds in the region and nation (Dunn, 2000), primarily associated with costs of harvested and purchased feeds. The proposed project will provide information and recommendations needed by producers to improve their economic and financial performance, reduce pressures to convert pasture and rangeland to crop production, improve the marketing opportunities for co-products, and strengthen value-added agriculture in the NCR.

Related, Current and Previous Work

Because total feed costs account for nearly half of the total costs of beef cow-production (Lawrence and Strohbehn, 1999; Moore, 1997; Rasby et al., 1989), profitability of beef cow-calf production may be improved by reducing the amounts of stored feeds fed (Gerrish et al., 1994). In order to reduce stored feed use, "extended" or "year-round" grazing systems have been developed utilizing stockpiled perennial grass and legume forages (Allen et al., 1992; Hitz and Russell, 1998; Adams et al., 1994) and/or crop residues (Klopfenstein et al., 1987; Russell et al., 1993) for winter grazing. In a review of the CRIS database, six projects were identified evaluating productivity and economic viability of extended or year-round grazing systems for beef cattle or training producers to use such systems. Projects in South Carolina and Delaware utilized forage resources that would be different than the NCR in their climates. The remaining projects, conducted in Iowa (Hersom, 1999; Janovick, 2003), Nebraska (Adams et al., 1994), and Pennsylvania have demonstrated the potential and limitations of extended grazing in the NCR, serving as the basis for this proposal to build on this concept.

Productivity of forage-livestock systems in the NCR is often limited by seasonality of forage growth. Cool-season grasses that predominate pastures in most of the NCR have limited productivity in mid- to late-summer. Consequently, cool-season grass pastures will typically be undergrazed during early summer, but overgrazed during mid- to late summer, resulting in low forage quantity and nutritional value (Beck and Russell, 1991; Hermann et al., 2002). While productive during mid-summer, warm-season grasses that predominate in the western portion of the NCR have little or no forage growth during early spring and fall (Rohweder and Albrecht, 1995) and may have low forage quality by mid-summer (Waller et al., 1986). During winter, grazing may be limited by weathering losses of nutrients through leaf loss and leaching (Hedtcke et al., 2002), grazing selectivity (Hersom, 1999; Hitz and Russell, 1998; Russell et al., 1993), and/or snow and ice cover greater than 0.5 m (Decker, 1988). Seasonal variation in productivity and nutritional value of pastures has resulted in impaired growth of stocker cattle (Moore et al., 2001) and reduced rebreeding rates in cows (Peters et al., 1992; Hermann et al., 2002).

Several different strategies have been evaluated to manage the seasonal distribution of forage production (Beuselinck et al., 1992; Lomas et al., 1999; Posler et al., 1993; Fritz et al., 1987; Roberts and Moore, 1990; Mitchell et al., 1994; Hersom, 1999; Janovick, 2003; Volesky, 1994). Using multiple forage species in complementary grazing systems is one approach to improve the uniformity of the forage supply. Complementary grazing systems involve rotating cattle among pastures consisting of forage species with different patterns of seasonal growth and development (Jung et al., 1985; Moore et al., 2001; Nichols, 1989). These systems typically utilize cool-season grasses for spring and fall grazing and warm-season grasses for summer grazing, based on seasonal dry matter accumulation (Anderson, 1988). Although warm-season grasses produce most of their growth during the summer months, forage quality of warm-season grasses may be low by mid-summer (Waller et al., 1986). Forages other than warm-season grasses may be used for complementary grazing (Hermann et al., 2002). In a review of the CRIS database, one project in Kentucky (KY0-06091) demonstrated that mid-summer grazing of Quickstand bermudagrass with or without clover supported greater growth rates than grazing tall fescue. Although use of forages in complementary grazing systems has been studied (Jung et al., 1985; Matches et al., 1974), no research to date has been designed specifically to develop complementary grazing systems on the basis of available nutrients, rather than on the basis of seasonal biomass accumulation.

Stockpiling of forages during late summer and fall for winter grazing has been an effective practice to reduce the feeding of stored feeds (Allen et al., 1992; Kallenbach et al., 2003b; Schoonmaker et al., 2003), but little documentation is available on the nutritional quality of different forages. The most commonly studied forage for stockpiling is tall fescue (Festuca arundinacea Schreb.), which resists nutrient loss longer than some other species (Matches and Burns, 1995). However, yields and nutritional value of stockpiled orchardgrass did not differ from tall fescue in Wisconsin (Hedtcke et al., 2002; Riesterer et al., 2000). Also, Hersom (1999) reported no difference in the amounts of supplemental hay needed to maintain gestating beef cows grazing stockpiled tall fescue-red clover or smooth bromegrass-red clover forage. Kallenbach et al. (2003a) demonstrated that tall fescue cultivars that contained no endophyte or contained a nontoxic endophyte had lower yields, but higher forage quality than tall fescue with toxic endophyte. Among legumes, birdsfoot trefoil (Lotus corniculatus L.) seems to stockpile better than others (Matches and Burns, 1995) inasmuch as the nutritive value of other legumes decreases rapidly after a killing frost (Hitz and Russell, 1998; Karsli et al., 1999).

If forage mass or nutritive value is limiting, use of supplemental feeds may be necessary to maintain productivity of grazing animals. Energy supplementation has increased daily gains in steers (Elizalde et al., 1998; Hess et al, 1996) and conception rates in cows (Marston et al., 1995) grazing during summer or winter. However, energy supplementation of grazing cattle with grain commonly reduces forage intake (Pordomingo et al., 1991), depending on forage quality and supplement source. The amount of forage substituted by grain supplementation is lower on forages with low crude protein concentrations (Caton and Dhuyvetter, 1997) or if the supplement is composed of highly digestible fiber sources like corn gluten feed or wheat bran (Elizalde et al., 1998; Hess et al., 1996). In the CRIS database, the relationship between corn grain and soy hulls as energy supplements for grazing cattle was being evaluated in one project (KY0-06091). Distillers grains are also an energy source that contains very little starch and, therefore, should not depress fiber digestion (Klopfenstein, 2001).

Forages such as mature warm-season grasses and crop residues contain low concentrations of crude protein; therefore, protein supplementation of cattle grazing these forages during the summer and/or winter may be necessary to optimize cattle weight gains and reproductive performance (Creighton et al., 2003). While cattle diets must contain some protein that is degradable in the rumen (DIP) to supply the needs of rumen microorganisms (Karsli, 1998), excessive amounts of degradable protein and inadequate amounts of undegraded protein (UIP) have reduced weight gains in growing cattle (Bodine and Purvis, 2003; Karges et al., 1992) and pregnancy rates and economic value in heifers (Paterson et al., 2003) grazing native range. Distillers grains are an excellent source of UIP (Klopfenstein, 2001). Furthermore, distillers grains contain high concentrations of phosphorus that is likely deficient in mature forages particularly during winter (Klopfenstein, 2001).

Because cow nutrient requirements vary with physiological stage (NRC, 1996), beef cows can lose body weight and condition if their nutrient requirements are not synchronized with forage supply and nutritional value (Adams et al., 1989; Adams et al., 1993). Thus, productivity of cows may be maintained if the cows lactation cycle is managed through calving and weaning dates to correspond with the availability and composition of pasture and range forage (Adams et al., 1996). Recent studies have shown that moving the calving season to late spring to match cow nutrient needs to availability of the forage supply reduces the amounts of hay fed and improves profitability (Clark et al., 1997; May et al., 1999). Thus, any evaluation of alternate forage species or supplementation strategies to overcome deficiencies in the forage supply for grazing needs to be compared within different cow reproductive and weaning management practices.

The National Research Council developed an empirical model to balance beef cattle diets and optimize animal production while minimizing feed costs and the environmental risks associated with excessive nutrient excretion (NRC, 1996). The model simultaneously determines nutrient requirements, estimates forage intake from energy concentration of the diet, and predicts change in body condition score for the cow as affected by body size, physiological stage, and environmental conditions (NRC, 1996). Patterson et al. (2003) and Loy et al. (2003) have demonstrated the NRC (1996) model is useful in developing and using nutrient management systems for beef cattle. However, limited knowledge of the composition of forage selected by cattle grazing pastures and rangeland in the NCR, as affected by species, location, season, and year, restricts the use of the NRC model for balancing the diets of grazing cattle (Adams and Short, 1988; Lardy et al. 1997). It is generally accepted that samples obtained from esophageal or ruminal-fistulated animals are different from the herbage available for grazing (Weir and Torell, 1959; Van Dyne and Torell, 1964; Schlegel et al., 2000). The NRC (1996) Nutrient Requirements for Beef Cattle was published with a library of nutrient composition that only contained a few entries for grazed forages. Published values of DIP and UIP content of grazed forages are more limiting than total digestible nutrient (TDN) or digestibility values of grazed forages and only recently have begun to appear in published literature (Hollingsworth-Jenkins et al., 1996; Lardy et al., 1999; Patterson et al., 2003). In a review of the CRIS database, there is one project (TEN00112) in which the metabolizable protein contents of forages in Tennessee are being characterized.

Objectives

1. To develop strategies that better match nutrient requirements of grazing cattle to the quantity and nutritional value of the forage supply in the North Central Region by: a) evaluating the adaptability, yield, and quality of summer annual forages across the NCR for use in complementary forage systems; b) evaluating forage quality from September to March of different cultivars from 24 perennial forage species grown in monoculture and stockpiled from mid-July; c) evaluating the ability of the grain processing co-product, distillers grains, to substitute for forages in summer and winter grazing systems of growing cattle; d) evaluating the economic and environmental potential of alternative forages and/or distillers grains in cow-calf production systems with different resource or animal management systems.
   
2. To develop educational materials and programs to improve decision-making for grazing-based beef production systems by: a) creating databases that can be used to expand the relevance of (i) 1996 Nutrient Requirements for Beef Cattle model to grazing conditions in the NCR and (ii) existing models/decision support tools for forage management and utilization (e.g., KansasGrazer and Grazing Land Applications) to annual and perennial forages in the NCR. b) conducting systems-based educational programs on integrated forage/cattle management systems for cattle producers; c) developing an educational program on the utilization of grain co-products.
   

Methods

Objective 1a. Nine summer annual forages will be evaluated in replicated trials conducted at research sites located in Iowa (42 59'N, 93 55'W and 40 77'N, 93 26'W), Kansas (37 11'N, 95 28'W; 39 10'N, 96 36'W; and 38 53'N, 99 17'W), Missouri (37 06'N 93 49'W and 38 57'N 092 20'W), Nebraska (41 8'N, 100 41'W; 40 51'N, 96 45'W; 41 52'N 103 36'W; and 42 23'N, 96 59'W), and North Dakota (47 30'N 99W). The experiment will be initiated in 2005 and repeated in 2006. Species to be evaluated are sudangrass (Sorghum bicolor (L.) Moench), pearlmillet (Pennisetum americanum (L.) Leeke), corn (Zea mays L.), crabgrass (Digitaria sanguinalis (L.) Scop.), oat (Avena sativa L.), Italian ryegrass (Lolium multiflorum Lam.), berseem clover (Trifolium alexandrinum L.), soybean (Glycine max (L.) Merr.), and tyfon (Brassica rapa L.). Sudangrass, pearlmillet, corn, and crabgrass will be planted at each location when soil temperature reaches 15C and the remaining species when it reaches 10C. Plot size will be 3 x 6 m. Soil type and texture will be characterized at each site and plots will be fertilized annually with phosphorus and potassium following recommendations based on local soil tests. Nitrogen will be applied to all species except berseem clover and soybean according to local recommendations. Daily climatic data, including soil temperature, air temperature, and precipitation will be collected at each site from planting until conclusion of harvests each year. Other weather measurements, such as solar radiation, relative humidity, and wind run will be reported based on nearby weather stations. Forage will be harvested from separate plots at two growth stages (mid-vegetative and early reproductive) to enable calculation of mean daily growth rate. Samples collected at each harvest will be analyzed for forage quality including total nitrogen (Keeney and Nelson, 1982), fiber constituents (Goering and Van Soest, 1970), and in vitro dry matter digestibility (Marten and Barnes, 1980). The experimental design at each location will be a randomized complete block design with four replications. Treatments will consist of factorial combinations of species and harvest date. Data will be analyzed using a combined analysis with years random, locations fixed, and blocks within locations random (McIntosh, 1983). Statistical analyses of treatment effects will be conducted using the General Linear Models (GLM) procedure of the Statistical Analysis System (SAS, 1991). The stability of yield of each species will be evaluated over multiple environments (year x location) using procedures described by Hildebrand and Russell (1996). Objective 1b. The species that will be evaluated are the major perennial forage species that are grown in the NCR. They include five perennial cool-season legumes (alfalfa, birdsfoot-trefoil, red clover, kura clover, and white clover), six perennial cool-season grasses (orchardgrass, tall fescue, intermediate wheatgrass, smooth bromegrass, timothy, and reed canarygrass), and four perennial warm-season grasses (switchgrass, big bluestem, indiangrass, eastern gamagrass). Additionally, mixtures of three cool-season legumes (alfalfa, birdsfoot trefoil, and red clover) with tall fescue will be evaluated to determine if quality changes when species are mixed together. Finally, to address differences in performance of cultivars within a species, two or three cultivars of alfalfa (grazing tolerant, non-grazing tolerant, and high-quality), birdsfoot trefoil (rhizomatous vs. non-rhizomatous), red clover, orchardgrass, tall fescue (endophyte infected and endophyte non-infected) will be included. The experiment will be arranged at each location (Ames, IA, Columbia, MO, Parsons, KS, and State College, PA) as a randomized complete block design with four replications. A split block restriction on randomization will be used, where functional group (legume, warm-, or cool-season grass) is the main plot and entries within the group constitute subplots. Each plot will be 2 x 7 m. All plots will be planted in the spring of the initial year of the experiment and allowed to establish until mid- to late-July. To allow time for adequate development of stands of the slower-establishing species, the experiment will be harvested but no data collected during the first one to two years after planting. The sampling regime will be as follows: monthly samples of 50 x 50 cm will be taken on 1 September, 1 October, 1 November, 1 December, 1 January, 1 February, and 1 March, or as near to the sampling date as weather permits. In the second year of the experiment, plots will be fertilized and managed for hay production (IA and KS) or grazing (PA), with all forage being stockpiled beginning after a mid- to late-July harvest. All plots will be harvested on the same day in July, although the cool-season species will have had an earlier harvest at the end of May or beginning of June. Sampling will proceed as specified above. After sampling, forage will be weighed, dried, and reweighed to determine the percent dry matter. Samples will then be ground and analyzed for in vitro dry matter disappearance, crude protein, and cell wall components (NDF, ADF, and ADL), using previously reported procedures described above. Objective 1c. In order to evaluate the use of grain co-products on performance and production costs of grazing cattle, research will be conducted under at least two types of forage supply: grasses during the growing season and dormant grass or crop residues during winter. Distillers grains will be used as the supplement because of their availability in all states at a relatively competitive price. Local sources of distillers grains will be used at each research site (KS, NE, OH, PA) even though composition of distillers grains varies among processing plants. To compensate for this lack of uniformity of product, all analyses will be conducted at one laboratory (NE). During summer grazing, distillers grains will be supplemented to yearling cattle grazing cool-season pastures (KS, NE, OH, PA) and warm-season range (KS, NE) typical of these states. A minimum of two levels of distillers grains including a zero control will be supplemented by either individual (NE, PA) or group feeding (KS, OH) using animal and pasture as the experimental units, respectively. Weight gain will be the primary measurement. An objective will be to determine the amount of forage substituted by supplementation. Because direct measurement of forage intake is very expensive, time consuming and often inaccurate, we propose to estimate forage intake from the NRC 1996 model using the net energy sub-model. Pen-fed studies have been used to validate the accuracy of the NRC model when yearling gains are 1.5 to 2.5 lb/day (Block et al., 2001). We will estimate forage intake by the cattle based on the intake of energy from the distillers grains and grazed forage and the measured gains of the cattle. To determine the net energy concentration of selected forage, samples of forages selected by esophageal-fistulated steers adapted to each pasture will be collected monthly and analyzed for digestible organic matter, crude protein and degradable protein. Forage composition also will be added to the database in objective 2a. In the winter, weanling calves will graze dormant grass or crop residues. The calves will be supplemented individually or by pen (pasture). Calves will be supplemented with two or more levels of distillers grains and a low-cost degradable protein source to meet DIP requirements. Calves will be weighed to determine performance. Forage samples will be collected and analyzed as in the summer grazing studies. Substitution of forage intake with distillers grains will be measured directly with a uniform protocol for measuring sward height, herbage mass or grazing allowance, and indirectly with the NRC (1996) model. When possible, body weight gains and feed efficiencies of yearlings in the feedlot after summer grazing will be measured. Furthermore, effects of supplementation on carcass characteristics also will be measured. The analyses of these systems across states will include response curves to distillers grains supplementation level and an overall economic analysis. Objective 1d. The use of distillers grains as a supplement for August-calving cows will be evaluated within the framework of the different cow management and forage resources available within each state. This evaluation will be compared in three systems in NE: (1) ad libitum sub-irrigated meadow during March calving, grazing range vegetation during summer, and ad libitum corn-stalk grazing during winter; (2) August-calving with ad libitum range grazing during summer and ad libitum corn-stalk grazing during winter; and (3) August-calving with controlled range grazing during summer and ad libitum corn-stalk grazing during winter. In IA, August-calving cows will graze cool-season grass pastures at a limited forage allowance during summer and will strip-graze stockpiled cool-season, grass-legume pastures at two stocking rates during winter. In both states, supplementation of August-calving cows with distillers dried grains will begin at calving and continue through weaning in March. The supplementation program will differ between the two states as the availability and composition of forages differ. Because of the low protein content of winter forages in NE, supplementation will be based on meeting the metabolizable protein requirements of the August-calving cows according to the NRC Nutrient Requirements for Beef Cattle model (NRC, 1996). Because land costs limit forage availability in IA, cows grazing one-half of the pastures at each stocking rate will be supplemented to meet cow energy needs to maintain body condition and milk production, while cows grazing the remaining pastures will not be supplemented. To evaluate the effects of distillers grains supplementation of grazing cattle on nutrient pollution of surface water sources, PA will also develop a grazing system for beef cows supplemented with distillers grains. In NE, March calves will be placed in a feedlot and fed to harvest at weaning while August calves will graze range with distillers grains supplementation before being placed in a feedlot and fed to harvest. Data will include cow body weight and cow body condition score at weaning, pre-calving, pre-breeding, pregnancy rate and weaning rate and calf birth and weaning weight. Furthermore, forage selected during grazing will be collected with cows or steers fitted with esophageal (NE, PA) or ruminal (IA) fistulae at least monthly throughout the year. These samples will be analyzed for digestible organic matter, crude protein, DIP and P as well as other organic and mineral constituents as appropriate. These data will be used in Objective 2a. Forage intake will be estimated in cows during the winter using marker techniques. In IA and PA, rainfall simulation analyses will be conducted each spring to determine the effects of supplementation on P run-off. Economic analyses will determine the costs and returns of each system. Objective 2a. A database of the composition of forages selected by grazing cattle will be developed to improve the relevance of the 1996 Nutrient Requirements for Beef Cattle model (NRC, 1996) for balancing diets in grazing systems of the NCR. The database will provide producers in the NCR with the tools needed to optimize nutritional balance and minimize excessive nutrient excretion from grazing cattle. Extrusa samples will be collected monthly for two years from grazing cattle either by direct sampling from cattle fitted with esophageal cannulae or by ruminal evacuation of cattle fitted with ruminal cannulae in Objectives 1c (KS, NE, OH, and PA) and 1d (IA, NE, PA). Additional samples will be collected biweekly from esophageally cannulated cows grazing NE Sandhills rangeland and southwest NE rangeland over two years. In order to adjust selectivity for the defoliation, defoliation will be expressed as the actual animal grazing days/ha divided by the recommended animal unit grazing days/ha for the specific pasture; where an animal grazing day will be 0.1 units/day for each 45.4 kg cow body weight plus 0.3 units/day for a suckling calf. In addition, uniform procedures for estimation of sward height and mass will be developed and utilized. Samples will be analyzed for IVOMD, CP, DIP, UIP and P, and regression models will be developed to relate composition to calendar dates within forage species. Effects of defoliation level on nutrient traits will be tested by multiple regression techniques. Where possible, forage samples also will be hand-clipped at a height comparable to grazing. Regression equations will be developed equating the composition of selected and available forage as affected by forage mass, height, and defoliation level. Samples of each forage will be stored to allow for further nutritional analysis, if additional funding is obtained. A database of the seasonal yields and forage quality of NCR annual and perennial forages will be developed that can be used to expand the breadth of existing models and decision support tools (e.g., KansasGrazer and Grazing Land Applications). Existing tools used for planning forage yields and utilization are based largely on rangeland conditions. Seasonal data on annual and perennial forage crops, especially those studied in Objectives 1a and 1b, have not been available for incorporation into the existing models. The environmental and plant-related data collected in Objectives 1a and 1b are critical for the improvement of models/decision support tools used in the NCR. Objective 2b. Information on the range of summer annual forage growth stages and related quality measures will be collected from each state and compiled to characterize broadly summer annual forages for summer grazing. The results of this multi-state effort will provide a myriad of educational opportunities that will ultimately be used to assist beef producers in extending the grazing season while minimizing the dependence on harvested forage. In addition to the forage and cattle performance measures, an economic analysis of the systems will be conducted to identify the critical decision points to examine under differing resources. The assembled information will be published in a variety of media to ensure that the broadest clientele audience is reached. For example, crop advisors and forage consultants may rely on results obtained from a variety of refereed publications such as the Forage and Grazing Lands Journal and Crop Management Journal. Additionally, the development of a regional CREES /ARS publication will be used by Cooperative Extension Specialists and County/District Extension educators as they disseminate information in each respective state. This publication will contain production information related to adaptability, yield and forage quality of summer annual forages across the NCR. In addition, economic tools to assist the producer in evaluating the costs of producing forages in livestock production systems will be included. For example, the opportunity cost of diverting the land out of crop production will be considered when planting summer annual forages on land that could be used for cash crops. Examples of educational settings in which this information will be extended include individual consultations, county/area training sessions, meetings, and grazing conferences and management schools. Moreover, this information will be made available in a variety of other multi-media outlets such as the Internet, radio and newspapers. The successful outcome and impact garnered from the 2002 conference series titled "Integrating Forage & Cattle Resources" that was co-sponsored by NC-225 provides an excellent benchmark for the development of future regional conferences. Future regional conferences and field days will be developed in cooperation with allied industry and organizations such as the American Forage and Grassland Council. The interaction with other entities will assist in leveraging outside funding to conduct these high profile educational events. Objective 2c. Existing literature on various processed grain co-products will be combined with the results of the current multi-state collaborative project (evaluating the use of distillers grains from the ethanol industry) from each NCR state to characterize broadly the utility of supplementing grain co-products in a grazing-based cattle production system. This multi-state effort will provide a myriad of educational opportunities that will be used to assist beef producers in developing strategies to extend the grazing season and reduce the harmful effects of drought to animals and pasture alike. As in Objective 2b, the assembled information will be published in a variety of media to ensure that the broadest clientele audience is reached. For example, the results of the collaborative project will be published in refereed publications such as the Professional Animal Scientist or the Journal of Animal Science. The proposed regional CSREES/ARS publication, described in 2b, will be used by Cooperative Extension Specialists and County/District Extension educators as they disseminate information within each respective state. Similar to Objective 2b, regional conferences and field days will be developed in cooperation with allied industry and organizations such as the National Cattlemen's Beef Association (NCBA) and the ethanol industry. The interaction with other entities will assist in leveraging outside funding to conduct these high profile educational events. Other means of disseminating this information will include individual consultations, county/area training sessions, grazing conferences and management schools, radio, newspapers, and the Internet.

Measurement of Progress and Results

Outputs

• Refereed publications on production, yield, quality, and utilization of summer annual forages and stockpiled perennial forages and on the use of distillers grains to supplement the diets of growing cattle and mature cows grazing both summer and winter pastures.
• Outreach publications targeted to crop and nutrition consultants and forage/livestock producers on approaches to increase the uniformity of the nutrient supply to grazing cattle either with the use of alternative forage species or supplementation with grain processing co-products. These publications will be distributed both by the use of journals such as Forage and Grazing Lands, Crop Management, and Professional Animal Scientist, and by the use of extension bulletins and fact sheets.
• A website to provide information on the project structure and organization, access to project publications, and links to relevant resources.
• Databases of (i) the compositon of commonly-grazed forages in native and introduced pastures and (ii) seasonal yields and ofrage quality of perennial and annual forage crops in the NCR. The database will be made available in common formats and will be accessible on the Internet.
• Regional conferences, workshops, and field days on the use of summer annual forages and grain co-products to augment the diets of livestock grazing summer and winter pastures in the NCR. Some of these activities will be conducted with collaboration of such organizations as the National Cattlemen's Beef Association, Northern Integrated Resource Management Group, and the state Forage and Grassland Associations to expand the audience and adaptation of practices.

Outcomes or Projected Impacts

• Determination of the nutritional value and utilization of complementary forages and supplementation with grain processing co-products to meet the nutrient requirements of beef cattle grazing summer and winter pastures.
• Production of management recommendations and educational materials for crop and livestock consultants and beef cattle producers on the use of summer annual forages, winter stockpiled forages and grain co-products to improve the nutritional status of grazing cattle.
• A nutrient composition database for forages common in the NCR that can be used to balance the nutrient requirements of grazing livestock in conjunction with the NRC Nutrient Requirements of Beef Cattle model with the objectives of improving animal production and profitability of beef cattle production while minimizing excretion of excess nutrients.
• IDevelopment of year-round forage programs, emphasizing grazing and use of co-products, could have a significant impact on land-use intensity and patterns in the NCR. These outcomes would likely lead to further research by the project team focusing on environmental and economic risks assoicated with changing land-use patterns. Possible sources of funding for such research would be programs in the USDA, including the National Research Initiative and the Risk Management Agency.
• Increased adoption of extended grazing management practices to improve the profitability of beef cattle production in the NCR.
• Maintenance of environmental quality in the NCR by reducing the conversion of grazing lands to cropland. Enhancement of the economic vitality of states in the NCR by providing an additional use for distillers grains with less environmental risk than feeding in a drylot.

Milestones

(2005): Establish plots of perennial forages for the stockpiled forage project.

(2005): Establish plots of annual forages for the summer annual forage project.

(2005): Initiate grazing project evaluating the use of distillers grains supplementation of growing cattle.

(2005): Initiate project evaluating the integration of distillers grains supplementation into grazing systems for beef cows.

(2007): Develop and participate in a series of regional conferences on the use of grain processing co-products in beef cattle grazing systems throughout the NCR.

(2009): Organize and participate in a series of conferences at multiple locations in the NCR demonstrating the integration of summer annual forages, winter stockpiled forages, nutritional supplementation and other management practices in the development of grazing systems that optimize profitability of beef cattle production while minimizing environmental impacts using tools like the Nutrient Requirements for Beef Cattle model and the forage composition database created in this project.

Projected Participation

View Appendix E: Participation

Outreach Plan

As described in Objective 2, this project will have a multi-faceted outreach program to transfer the technologies developed. Traditional methods such as publication in extension bulletins available to producers and extension educators and in journals such as the Forage and Grazing Land Journal and Crop Management Journal used by crop and livestock consultants and presentations in individual consultations, county/area training sessions, grazing workshops, and field days will be used. In addition, the outreach plan will have several novel approaches. First, databases of the (i) composition of forages selected by grazing cattle and (ii) seasonal yields and forage quality of perennial and annual forage crops in the NCR will be developed and posted on the project's website. These databases will be used by producers with computer models such as the 1996 Nutrient Requirements of Beef Cattle and the KansasGrazer to optimize forage utilization by grazing cattle. The second novel approach will be to organize and conduct two series of conferences at several locations around the NCR training cattle producers in the optimal use of management tools such as summer annual forages, winter stockpiled forages, nutritional supplementation and the forage composition database to enhance the profitability and environmental sustainability of forage-based beef production systems. Using the success of a similar series in the NC-225 regional research project as a model, the proposed conference series will be done in cooperation with the National Cattlemens Beef Association, the Northern Integrated Resource Management Group and similar organizations.

Organization/Governance

The project will be governed by two officers: a chair and a secretary. Project participants will initially elect the two officers who will serve the first year. For each succeeding year, the secretary will become the chair for the following year and a new secretary will be elected. Terms for each will start at the end of the annual meeting. The chair and secretary will be responsible for conducting necessary business in close coordination with the administrative advisor. The duties of the secretary will be to take meeting minutes, prepare the approved minutes and the annual report, and other duties as assigned by the chair. The chair will conduct the annual meeting and with the help of the secretary coordinate any other reports or proposals as required. The chair will appoint subcommittees for each project objective. Subcommittees will be responsible for drafting uniform research procedures for each objective, subject to approval by project members and preparation of materials and meetings for technology transfer.

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Attachments

Land Grant Participating States/Institutions

AL, KS, NE, OH, SD

Non Land Grant Participating States/Institutions