NC1020: Beef Cattle Grazing Systems that Improve Production and Profitability While Minimizing Risk and Environmental Impacts (NC225)
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.
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