Location: Dale Bumpers Small Farms Research Center2010 Annual Report
1a. Objectives (from AD-416)
Objective 1: Determine effects of plant and endophyte genetics, management practices, and environmental conditions on sward yield, persistence, and forage quality and anti-quality factors, and the resulting animal response in forage systems in which tall fescue is a component. Subobjective 1.A. Develop a better understanding of plant physiological processes that impart persistence in tall fescue and the interaction between the plant and Neotyphodium endophyte in these processes. Use this new understanding and plant selection techniques to develop new populations of tall fescue that are either endophyte free or contain nontoxic endophytes that promote host persistence under grazing. Subobjective 1.B. Determine the potential toxicity of tall fescue grazing systems, including complementary grazing, intensive grazing, and stockpiling, by better understanding how plant physiological, morphological, and genetics factors, and pre- and post-harvest management decisions affect ergot alkaloid content. Objective 2: Determine management schemes for the sustainable production of small ruminants from temperate pastures. Objective 3: Improve inorganic and organic fertilizer use efficiency in pastures. Subobjective 3.A. Improve the efficiency of organic and inorganic fertilizer use in pastures by incorporating nutrients into the soil. Subobjective 3.B. Evaluate the effects of grazing systems and buffers on the loss of agrochemicals from pastures and hay fields.
1b. Approach (from AD-416)
Replicated field experiments will evaluate cow-calf and stocker management practices and genotypes on novel endophyte-free or -infected tall fescue pastures to alleviate fescue toxicosis and improve calf production. Grazing and management systems will be developed for sheep and goat production to manage gastrointestinal nematodes and improve post-weaning gains of lambs and kids. A tractor-drawn implement to incorporate poultry litter under the soil surface in perennial pasture will be developed, and a comparison of nutrient losses from applied poultry litter compared to conventional surface application will be examined. Cattle grazing systems and buffers will be examined to reduce the loss of agrochemicals from pastures and hay fields by collecting runoff water samples from watersheds for sediment and nutrient analyses and soil properties will be characterized. Management practices will be evaluated that optimize the proportion of a landscape/farm in temperate pastures and silvopastures to maximize environmental and economic returns. Potential bioenergy feedstocks will be examined for their suitability to integration in mid-South pasture and silvopasture systems.
3. Progress Report
The effects of drought on endophyte-free and infected tall fescue were examined. Expression of stress proteins and membrane stability was greater for the natural, nontoxic endophyte than the endophyte-free type. Higher antioxidant activity afforded by endophyte stimulation of superoxide dismutase (SOD) activity may be a key mechanism by which plasma membranes are protected against lipid peroxidation, and can thus retain viability until water supply becomes favorable. To understand how tall fescue pasture management affects ergot alkaloid content, studies were conducted in collaboration with University of Missouri. One study showed that ergovaline in tall fescue increased by 20% after treatment with chemical fertilizer compared with poultry litter. In another, low rates of clethodim, an herbicide, functions like a growth regulator and lowers toxin levels when applied in the spring. In another study with University of Missouri, University of Georgia, and Clemson University, it was determined that if tall fescue is prohibited from reaching reproductive maturity, ergovaline concentrations in the spring decrease to near nontoxic levels. Further, clipping tall fescue to 2 inches or less reduces concentrations of ergovaline by as much as 100 parts per billion. Grazing strategies of sericea lespedeza were examined to maximize parasite control and weight gains in lambs and kids. Goat kids were able to immediately graze sericea lespedeza for decreased parasite infection, but lambs needed the presence of the dam to introduce them to the plant to express parasite control. The best use of the sericea lespedeza for both was in combination with mixed grasses rather than a pure stand. Short-term feeding of sericea lespedeza may inhibit establishment of the worms in goats, but only reduce fecundity of the already established worm. Testing of a tractor-drawn implement to incorporate poultry litter under the soil surface has continued with field studies in AR, KY, MD, MS, and PA. We completed a study on potential sources of shade tolerance in tall fescue. Eleven genotypes were identified, and further studies will be conducted on these to determine their sustainability within this system.
1. Integrated control of gastrointestinal parasites using sericea lespedeza and copper oxide wire particles. Alternatives to chemicals are needed for control of worms in sheep and goats because of drug resistance and a desire to reduce chemical residues in meat products. Copper oxide wire particles (COWP) and sericea lespedeza have been useful in controlling worms in sheep and goats, but little information is available on combining these tools, especially around lambing or kidding time. Scientists at the Dale Bumpers Small Farms Research Center, Booneville, Arkansas, Louisiana State University, Auburn University, and Fort Valley State University, Georgia, determined that both sericea lespedeza and COWP together aided in the control of worms around the time of birth, and both can be included in a complete feed. These results indicate that COWP and sericea lespedeza can be used as tools for the control of worms, saving producers cost of chemical dewormers and reducing number of livestock deaths due to parasites; these tools should be integrated with good management and nutrition for optimal worm control. The information is useful for small ruminant producers, veterinarians, scientists, and extension specialists that work with sheep and goats.
2. Understanding drought tolerance of tall fescue grass. Temperate pastures are essential for grazing livestock in the U.S., but summer drought can limit sustainability of these grasses, including tall fescue. Scientists at the University of Arkansas and University of Missouri determined that endophyte-infected tall fescue compared with endophyte-free strains has a greater capacity to withstand stress due to drought. Also, summer-dormant tall fescue genotypes have substantially greater inherent drought tolerance than summer-active genotypes, regardless of endophyte-infection status. This information is useful to forage, cattle, sheep and goat producers, scientists and extension specialists in managing forage or animals grazing tall fescue pastures.
5. Significant Activities that Support Special Target Populations
Scientists have participated in activities targeting minority, historically under-served operators/stakeholders including: 1) collaborator on a SARE grant awarded to 1890s institution, Fort Valley State University, and on a SARE grant awarded to this USDA, ARS station with Fort Valley State University listed as a co-principal investigator; 2) cooperator on Capacity Building Grants awarded to Fort Valley State University, Delaware State University, Virginia State University, and University of Maryland Eastern Shore; 3) participated in meetings of the Southern Consortium for Small Ruminant Parasite Control, attended by 1890s institute representatives from Fort Valley State University, North Carolina A&T State University, Delaware State University, and the Hispanic-serving University of Puerto Rico; 4) collaboration with University of Maryland Eastern Shore on tractor implement to incorporate poultry litter into soil for fertilizer; 5) review of abstracts for the National Goat Conference to be held at Florida A&M University, Tallahassee, FL; 6) provided an informational exhibit at the Sixth Annual Tennessee Small Farm Expo and Small Farmer Recognition Program in McMinnville, Tennessee at the Otis Floyd Nursery Research Center. Scientists have participated in activities targeting small farmers, including: 1) education of small ruminant extension agents and producers in the use of methods to control gastrointestinal parasites; 2) review panel for Southern Region SARE producer and graduate student grants; 3) on-farm organic research in small ruminants at the Heifer Ranch of Heifer International, Perryville, AR, and a private farm in Arkansas; 4) hosting a field day for small ruminant producers; 5) participation with ARS stations in Lane, OK, and Fayetteville, AR, in the Know Your Farmer, Know Your Food Conference in El Reno, OK; 6) cooperation with small family farm in Alabama on a USDA, SBIR grant; 7) led SARE project with sheep producers (small farmers) from Arkansas, Georgia, and Ohio on genetic improvement indices; 8) cooperation with the ARS station in Fayetteville, AR, on a NIFA Beginning Farmers and Ranchers Development grant targeting small farmers, women, and minority groups.