Location: Forage and Livestock Production Research2009 Annual Report
1a. Objectives (from AD-416)
The primary goal is to develop a knowledge base and guidelines that will enable producers in the southern Great Plains to diversify forage-based systems, to enhance flexibility and efficiency, and to reduce economic and environmental risks under variable climate, market and policy conditions. The approach is to develop sustainable systems that integrate a diversity of plant species including forages for livestock, multi-purpose crops, and biomass production. Specific objectives include: Objective 1: Provide perennial grasses to regional livestock producers that are adapted, productive, persistent, exhibit desired agronomic characteristics, and can be included in year-round forage based production systems. • Sub-objective 1.A. Develop and evaluate germplasm resources of perennial cool-season grass forages that exhibit favorable agronomic characteristics and are adapted to the climate of the southern Great Plains. • Sub-objective 1.B. Develop PCR-based molecular markers to assist perennial cool-season grass breeding, with emphasis on bluegrasses. • Sub-objective 1.C. Evaluate smooth bromegrass, wheatgrasses, and tall fescues under intensive, short-duration grazing during spring and fall in near year-long forage production systems. Objective 2: Evaluate quality and anti-quality factors in existing forage based livestock production systems that limit animal performance. • Sub-objective 2.A. Evaluate adapted winter wheat cultivars and breeding lines for variation in concentrations of secondary metabolites that may limit the incidence of frothy bloat, and for accumulation of nitrate that may limit performance of cattle grazing wheat forage. • Sub-objective 2.B. Provide a real-time, remote-sensing based approach for estimating forage quality in the field. Objective 3: Incorporate multipurpose legume and grass forage, grain, and biomass crops into integrated and diversified systems that provide a range of agricultural opportunities. • Sub-objective 3.A. Assess the feasibility of integrating multipurpose forage and grain crops into diversified forage and livestock production systems. • Sub-objective 3.B. Provide the knowledge and guidelines required to integrate biomass/bioenergy crops into agricultural land management systems of the southern Great Plains. • Sub-objective 3.C. Assess amounts of nitrogen contributed to subsequent forage, grain and biomass crops by annual and perennial legumes. Objective 4: Provide the knowledge and guidelines required to implement and manage year-long forage based livestock production systems. • Sub-objective 4.A. Design, install, and evaluate farm-scale, year-long forage production systems that include multiple forage species to fill gaps in spring and fall when high-quality forage is not available. • Sub-objective 4.B. Determine whether fast-growing annual legumes and grasses have potential as gap-filling forages for use in near year-long forage production systems in the southern Great Plains.
1b. Approach (from AD-416)
Germplasm with potential for use in the region will be obtained from a variety of sources and evaluated in the field for adaptation, productivity, forage quality, and other traits. Persistence, productivity, and quality of selected perennial cool-season grasses will be genetically improved through traditional and marker assisted breeding methods and interspecific hybridization. Forage crop sequences, including grass, legumes, and legume/grass mixtures will be evaluated in the field under varying levels of fertilization, grazing pressure, and abiotic stress. Hyperspectral reflectance data will be compared to laboratory analyses and bench top near-infrared spectroscopy as an approach to monitoring in-field forage quality and biomass production. Productive and adapted bioenergy feedstock crops will be identified and efficient feedstock production systems developed. Approaches to incorporate feedstock production into existing forage and livestock production systems will be investigated. All proposed research will be in collaboration with ARS, university and private cooperators where appropriate and mutually beneficial.
3. Progress Report
The smooth bromegrass and fescue materials were transferred via a materials transfer agreement (MTA), and the cooperative research development agreement (CRADA #58-3K95-8-1233, Germplasm Enhancement of Tall Fescue) for commercial multi-location performance trials was continued. An invention disclosure related to the development of dihaploid Lolium spp. was submitted to the USDA-OTT and accepted for a U.S. patent application on Sept. 30, 2008. One 'creeping wheatgrass selection' remains under performance evaluation for commercial seed production by Barenbrug Seeds. Three-year performance trials of orchardgrass varieties Nakei 26 and Nakei 27 and a 'stress-tolerant' orchardgrass were initiated. Approximately 380 Poa SSR and palindrome associated molecular markers were generated and evaluated against eight Poa species and their interspecific hybrids. The markers were utilized in 2007 and 2008 to identify an androgenic development process in P. arachnifera (Texas bluegrass), which is a process that can be utilized to bypass barriers of apomictic development and enhance the efficiency of breeding of apomictic Poa. In cooperation with Noble Foundation, Ardmore, OK, scientists are continuing to conduct short-term (30- to 35-day periods) intensive grazing studies on pastures of non-toxic endophyte-infected tall fescues in October and May. Stocker cattle have gained 1.7 to 2 lb per day in October and 2 to 2.5 lb per day in May. Pastures of introduced tall wheatgrass have been included in the study, and have produced similar responses. Expansion of the tannin research has led to the development of a grant project funded by the Animal Compassion Foundation associated with Whole Foods Market and an in-house project evaluating the usefulness of tannins in Ozark Plateau forbs and in peanut skins as anthelmintic agents for sheep and goats. Preliminary results from pastures of non-toxic endophyte-infected tall fescues and wheatgrass, wheat, mixtures of annual grasses and legumes, and perennial warm-season grasses indicate that stocker cattle can gain 500 to 600 lb on forages. Continue to evaluate combinations of annuals, including grasses and legumes, as an alternative to perennial forage pastures. Cool-season mixes of annual rye, wheat, and annual ryegrass, with and without red clover, have provided forage to allow grazing by stocker cattle during November through May, and supported average daily gains of 1.7 to 2.5 lb per day. Warm-season mixes of sorghum-sudangrass with and without lablab, or soybean provided high-quality forage during July through August, and supported similar weight gains. Redcedar (Juniperus virginiana L.) is an invasive species that seriously degrades prairie grasslands and adjacent landscapes in the southern Great Plains. Ongoing research has determined that a large redcedar biofuel feedstock exists and a range of 14 to 40 t ha-1 of dry feedstock on invested land is available. Satellite imagery is being utilized to accurately locate and quantify this resource.
1. Can Conservation Reserve Program land contribute to biofuel production?: Among the proposals for acquiring biofuel feedstock, without impacting other land uses such as food or forage, is the use of up to 50% of Conservation Reserve Program (CRP) land. Scientists from the Forage and Livestock Production Research Unit at El Reno, OK, showed that Old World bluestem produced an average of 3380 lbs/acre and native mix produced 1710 lbs/acre of dry biomass feedstock across all years, locations, and harvest dates. Maximum yields were obtained at the October harvest for both Old World bluestem (3720 lbs/acre) and the native mixed species (1950 lbs/acre). At the native mixed species sites, there was no observed change in species composition. Soil characteristics, as a result of annual harvest for three years, were not altered but biomass production consistently declined at all sites and for all harvest dates over the three harvest years. If sustained biomass feedstock production is to be feasible from CRP land in this region of Oklahoma, harvest management and nutrient replacement will be important considerations.
2. Forage sorghum and sorghum/sudan hybrids excel at biomass production: As the bioenergy industry expands, producers choosing to shift current forage crop production to dedicated biomass crops will find it advantageous to grow low-risk multi-purpose crops that maximize management options. Special sorghum hybrids have been developed that are capable of impressive biomass yields and tolerance to environmental stress. Scientists from the Forage and Livestock Production Research Unit at El Reno, OK, showed that average yield for a single late-season harvest was 12 tons per acre of dry matter per year. Average yield for a first harvest plus a ratoon crop was 11.4 tons per acre of dry matter per year. The best performing cultivar yielded almost 18 tons per acre of dry matter for a single late season harvest. Results from this research demonstrate that there are sorghum cultivars with high yield potential that can provide management options for producers that will minimize their risk while maximizing their forage or bioenergy feedstock production at the same time.
3. Feasibility of developing wheat forage that is less likely to give rise to pasture bloat: Even though winter wheat pasture in the southern Great Plains is considered excellent forage, devastating losses of stocker cattle can occur due to pasture bloat. Tannins are known to reduce the incidence and severity of bloat. Scientists from the Forage and Livestock Production Research Unit at El Reno, OK, examined adapted wheat varieties that are commonly grazed and a set of 221 diverse breeding lines to evaluate the feasibility of using traditional breeding methods to give producers a passive choice to reduce the incidence of bloat using improved varieties. Tannin reactive substances (phenolic acids and condensed tannins) were detected in extracts from adapted varieties and experimental lines. Differences in phenolic acids among the experimental lines were significant (range, 14.8-32.8 mg/g dry weight); those of condensed tannin were not (range 1.46-4.82 mg/g dry weight). While we observed marked differences in tannin substances among the experiments, even the greatest amounts detected are unlikely sufficient to render the forage bloat-safe. These results will be useful to wheat breeders seeking to develop varieties better suited for use in the southern Great Plains.
4. Poa molecular marker development enhances traditional breeding of bluegrass: The development and implementation of molecular marker-based systems for marker-assisted improvements in grass forages has lagged behind similar achievements for cereal grass species such as wheat, corn, rice, and sorghum. This is due primarily to the high cost and the time-consuming nature of marker development and the lack of emphasis placed on non-food grasses utilized as a livestock forage. A research marker for forage bluegrass developed by a scientist from the Forage and Livestock Production Research Unit at El Reno, OK, has resulted in the development of 157 molecular markers that have application across a wide range of Poa species. The availability of these markers and their high specificity makes these markers useful for DNA fingerprinting, cultivar identification, and marker-assisted selection studies. Forage or turf bluegrass breeders should find these markers a valuable addition to their breeding and selection programs.
5. Identification of an alternative reproductive method in Texas bluegrass: Bluegrass represents a major grass species commonly utilized for both forage and turf. A Scientist from the Forage and Livestock Production Research Unit at El Reno, OK, has identified a novel method of utilizing a sexual reproducing native species, Texas bluegrass, as the female parent to facilitate the production of genetically diverse offspring from both non-sexual and sexual bluegrass species. The examination of 2041 hybrids, using Texas bluegrass as the female female parent and Kentucky bluegrass, Sandberg bluegrass, and Argentine bluegrass as male parents, resulted in 31 individuals that lacked a Texas bluegrass genome contribution and supported only the genomes of either Kentucky, Sandberg, or Argentine bluegrass. Molecular marker analysis of these individuals confirmed they possessed only the genome equivalent of the male parent utilized in the hybridization. This special class of hybrids occurred at a frequency of 1.5%, regardless of which bluegrass species was utilized as the male parent. The generation and identification of this special type of hybrid offers a new approach for developing new and diverse Poa breeding resources or cultivars.
5. Significant Activities that Support Special Target Populations
Research under this project is conducted in close collaboration with the staff of Langston University, a 1890s university located at Langston, OK, and the scientists of the Grazinglands Research Laboratory who are permanently stationed at Langston University (project 6218-12210-003-00D). That research project addresses the unique problems encountered by small, minority, and socially disadvantaged/limited resource forage and livestock producers. During the fiscal year, scientists stationed at El Reno worked closely with faculty and students at Langston University to provide training, grant-writing assistance, and research experiences.