SCC81: Sustainable Small Ruminant Production in the Southeastern U.S.
(Multistate Research Coordinating Committee and Information Exchange Group)
SCC81: Sustainable Small Ruminant Production in the Southeastern U.S.
Duration: 10/01/2017 to 09/30/2022
Statement of Issues and Justification
Small ruminants remain a vital component of many small farms in the Southeastern U.S. providing milk, meat and fiber, as well as a means to control brush. In addition to conventional and ethnic markets, there is a growing demand for grass finished, organic, and local meat products (USDA, NASS, 2012, 2015). Small ruminants have been in decline partly due to an increasing challenge in internal parasites due to loss of effective dewormers and warmer temperatures much of the year. Small ruminants in much of the U.S. are exposed to gastrointestinal nematodes (GIN) when grazing pastures in warm, humid conditions or irrigated pastures. Minimizing the use of pharmaceutical products and focusing on other means of control (Whitley et al., 2014) such as fungus feeding addresses both conventional and organic production. The most promising means of GIN control is genetic resistance, or an animal’s ability to resist infection with GIN. The National Sheep Improvement Program (NSIP) includes estimated breeding values (EBVs) for parasite resistance as worm egg count (Aaron, 2014) in the Katahdin breed and to a lesser degree other breeds and goats. Research is needed on the value of EBVs, selection criteria for EBVs and relationships among EBVs for parasite resistance and other production traits (ASI, 2016), as well as wider use of EBVs by goats that are plagued by GIN to a greater degree than sheep. It is important to understand how the immune system functions in susceptible and resistant animals to fine tune selection for resistance. And, while the group has made great strides on forage management and condensed tannin rich forages such as sericea lespedeza (Coffey et al. 2007) for GIN control, further research is needed to examine the importance of native plants with secondary plant compounds, and meeting both production goals and GIN control with existing GIN important forages and grazing systems.
There are plenty of forages and pasture land in the southeast, but low quality summer forages creates challenges to meet nutrient requirements of livestock. Nutrient deficiencies can be met through supplements, but economics should be considered among those readily available to farmers. Similarly, while planting annuals can often improve nutrient quality in pastures, cost and risk of planting should be considered. Silvopasture creates an environment that allows for extended use of more nutritious cool season forages, and may augment GIN control since rotational management is necessary, and provide a means to address warmer temperatures and climate change. Multi-species grazing is considered important for maximizing forage feeding systems and can also assist with GIN control as well. However, little has been published on these systems for small ruminants. Finally, according to the ASI’s “U.S. Sheep Industry Research, Development and Education Priorities” publication (2016), grazing and forage management, along with flock health, genetics and reproduction were all listed in the top 8 producer challenges as defined by percentage of operations.
Increasing reproductive efficiency is vital to profitability and sustainability of small ruminant production. Out-of-season breeding research is a priority for the sheep industry (ASI, 2016), but is also important in goat production to increase income and manage seasonal supply of small ruminant products. Reproductive management for seasonal control may also benefit production through optimal management of grazing resources and GIN control benefits. In furtherance of genetic improvements and animal health, being able to expand genetic resources is also important. Use of artificial insemination (AI) is one method to do this, but effective, producer-friendly AI techniques are lacking, especially in sheep. Effective vaginal AI and cooled/frozen semen as well as estrus synchronization methodology for sheep and goats would go a long way towards improving flocks and herds and increase productivity and profitability for the industries, and this research is underway (Wildeus et al., 2016). Understanding reproductive function in small ruminants on a basic level and seasonal, nutritional and other impacts on this is important to increase efficiency and impacts effectiveness of estrous synchronization and out of season breeding protocols; more research is needed in this area, especially in regard to male reproductive capacity.
Because of dwindling resources for extension programs, it is imperative that we find a means to disseminate our research and transfer technologies developed from it. This can be achieved through online programs, websites, and train-the-trainer programs. These research and outreach priorities on GIN control, forage feeding programs, and improvements in reproduction require coordinated efforts of multiple research institutions, each contributing their specific expertise towards the design of integrated systems.
Utilization of gastrointestinal nematode (GIN) control methods including selective deworming, forage/grazing management, and animal selection for GIN resistance
Emphasis of forage feeding systems for year-round grazing to meet nutritional requirements that mitigate drought and other plant and animal stressors
Strategies for the improvement of small ruminant reproduction
Disseminate research results and information to stakeholders
Procedures and Activities
Objective 1: Methods of GIN control will include genetic selection, forage/grazing management, and selective deworming or the strategic use of anthelmintics. Other control methods may include condensed tannin containing forages, grazing systems, and nematode-trapping fungi. Participating agencies include Fort Valley State University (GA), USDA ARS Booneville and the University of Arkansas (AR), West Virginia University (WV), University of Maryland (MD), Tuskegee University (AL), Delaware State University (DE), Virginia State University (VA), and Louisiana State University (LA). Collaborating institutions to examine GIN resistant genetics and relationships among the EBVs generated by NSIP are AL, AR, WV, DE, GA. The development of genetic markers or polymorphisms and association with resistant genetic phenotypes will be explored by AR, WV and collaborators. Trials at WV will measure specific immune responses of resistant breeds during a primary and challenge infection with Haemonchus contortus to elucidate mechanisms of immunity. Institutions to examine integration of nonchemical control of GIN in conventional and organic production systems include GA, AR and LA (fungus). Studies involving condensed tannin containing forages including birdsfoot trefoil, sericea lespedeza and native legumes will occur at all participating agencies to evaluate potential both as a forage (grazing schemes and fed fresh) and processed (hay, haylage, silage, pellets). The results of these trials will lead to an integrated strategy for controlling worms on commercial and breeding operations that manage conventionally or organically.
Objective 2: Cool-season and warm-season annual and perennial forages, including native grasses and legumes will be established in conventional and organic pasture, evaluated and compared to determine forage availability and quality, stocking rate, and animal performance during different stages of production by AR and GA for sheep or goat production systems. At AL, silvopasture systems with and without annual forages will be examined for goat production, and AR and GA will consider benefits of silvopasture for sheep and cattle. GA and AR will examine use of natives in a pasture system for pollinator benefits as well as improving diversity of the pasture system, providing additional quality summer grazing and possible control of GIN at the pasture life cycle stage. Native and other varieties of sericea lespedeza will be examined in a pasture system as a summer grazing/hay crop for small ruminants by GA and AR. Supplementation with low cost feeds will occur at DE, VA, MD, and University of Virgin Islands (VI).
Objective 3: Reproductive technologies including development of and/or refinement of vaginal artificial insemination with fresh cooled and frozen semen in sheep and goats will be investigated by VA and AR with collaboration from MD and DE. Out-of-season breeding regimes and/or estrous synchronization protocols will be refined for use with natural and artificial mating schemes, comparing results in different breeds as appropriate to the institution (AL, DE, VA, WV, VI, GA). AL will investigate testicular function and development in goats for furthering reproductive efficiency. Reproductive function and performance in different breeds/breed types or within crossbreeding systems will be investigated by VA, VI, WV, and GA. Genetic components of reproductive performance (such as maternal EBVs) and impacts on those with selection for other traits will be included in research conducted at AR and WV.
Objective 4: Producer workshops, which teach the use of integrated parasite control methods, will be taught throughout the region, with at least 5 conducted each year. Parasite control will continue to be an important educational focus. Efforts are strongly supported by the work in the other objectives. Local, county and regional meetings will be held in each of the states. Efforts will continue to update extension field faculty on small ruminant production and management. Information for agricultural professionals including Extension staff and producers among others will be posted to various web sites including those managed by KY, GA, and MD2 (Maryland Small Ruminant Page at www.sheepandgoat.com; American Consortium for Small Ruminant Parasite Control at www.wormx.info). Efforts will be made to continue to support the eXtension Goat Industry as an online information source to producers.
Expected Outcomes and Impacts
- Improved selection for sheep and goats resistant to GIN to reduce the need for deworming.
- Increased participation in NSIP.
- Increased use of artificial insemination and other reproductive management techniques.
- Increased use of alternative control methods involving forages and forage management by producers.
- Improved forage-based systems for conventional and organic small ruminant production.
- Knowledge of small ruminant grazing practices that support pollinator habitat.
- Improved summer gains for growing lambs and kids on forage-based systems.
- Exchange of ideas and information.
- Coordination of specific research and extension programs to accelerate goals.
- Identification of critical research objectives.
- Improved outreach to scientific community and producers.
Projected ParticipationView Appendix E: Participation
Technical committee members of this project have been involved in organizing producer workshops and field days at their respective institutions. These events will be the basis of the educational and outreach activities of this project. The project will facilitate the coordination of these activities and provide a range of subject matter expertise in the selection of the presenters at workshops and field days. Members will prepare articles for publication in industry magazines. There are several participants from 1890 Land Grant institutions that have a special mandate to serve under-represented groups and small-scale, limited resource farmers. These groups have shown a particular interest in small ruminant production that will benefit from activities from this project.