Location: Forage-animal Production Research
Project Number: 5042-32630-004-009-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: May 1, 2023
End Date: Apr 30, 2024
Objective 1: Determine how secondary metabolites influence positive and negative changes in grazing livestock physiology; and how biological and genetic factors influence the incidence of fescue toxicosis and develop strategies to reduce impacts. Work will be arranged in the following subobjectives: Sub-objective 1.A: Investigate the interaction of serotonin and ergot alkaloid (EA) exposure to determine if serotonin can compete with EA at the receptor level. Sub-objective 1.B: Determination of the optimum dose of L-DOPA, and the use of L-DOPA to mitigate the decrease of feed intake provoked by EA. Sub-objective 1.C: Determine the effect of leucine, glucose, and acetate infusion on mTOR pathway activation in muscle and adipose tissue, determine infusion rates of leucine, glucose, and acetate required to achieve submaximal and maximal activation of mTOR and downstream proteins in muscle and adipose tissue, determine the effects of fescue-derived alkaloids on muscle and adipose mTOR activation. Sub-objective 1.D: Use remote sensing technology to generate a phenotype of ergot alkaloid exposure that can be used to characterize genetic tolerance to these toxins. Objective 2: Effects of clover isoflavones on development, finishing and meat quality in fescue-based pastures. Work will be arranged in the following subobjectives: Sub-objective 2.A: To determine the effect of isoflavone supplementation via red clover during post-weaning management on nutrient utilization and performance of grazing and confinement-finished lambs. Sub-objective 2.B: Examine the effect of isoflavone supplementation during post-weaning management on carcass traits, muscle proteome, and meat quality of grazing and confinement-finished lambs. Sub-objective 2.C: Evaluate the impact of dietary isoflavone supplementation on the rates of antimicrobial resistance (AMR). Objective 3: Identify the impacts of environmental and nutritional adaptation on development and develop strategies to improve reproductive and growth performance. Work will be arranged in the following subobjectives: Sub-objective 3.A: Investigate the impacts of pre-weaning nutritional management on microbial development, health and performance of beef calves and lambs. Sub-objective 3.B: Investigate the role of adaptation to grazing system and environment on rumen microbial communities, nutrient utilization, reproductive, and growth performance in first calf beef heifers. Sub-objective 3.C: Determine how ergot alkaloid exposure, grazing system, and environment influence calf microbial development, health, and performance. Sub-objective 3.D: Evaluation of the form of supplemental selenium to ameliorate fescue toxicosis in lactating beef cows consuming toxic E+ TF (TF). Sub-objective 3.E: Manipulation of the form of supplemental selenium (Se) to increase fertility in beef cattle.
The objectives will be completed by teams of cooperator faculty, staff, and students in collaboration with USDA-ARS researchers as described in project plan 5042-32630-004-00D, entitled, “The Roles of Forage Phytochemicals at the Plant-Microbe-Animal Nexus for Sustainable Ruminant Agriculture.” Forage systems provide inexpensive feed, conserve soil and water resources, and mitigate environment impacts. However, basic biological information is limited on how plant metabolites affect animal performance, health, and wellbeing. To improve the sustainability of forage-based enterprises, it is essential to develop a knowledge base of the fundamental biological processes underlying the interactions between the animal, plant, and pasture ecosystems. This Non-Assistance Cooperative Agreement (NACA) proposes to help ascertain the complex interactions within the animal-plant environment interface and to improve forage production, animal performance, health and well-being. Research is focused on the utilization and production of the predominant forages in the South Eastern transition zone of the United States. A variety of scientific approaches are used by the 26 doctoral-level scientists conducting the research. Methodologies include: fundamental molecular biology of plants and animals, physiology of plants and their endophytes, physiology of animals and their microbiota, novel plot experiments, feeding trials with unique microbiological measurements and grazing studies place the more basic work in the context of management. Accomplishing the objectives of the NACA will improve productivity and sustainability of forage-based enterprises through improved understanding, rational management strategies and novel technologies.