Location: Forage and Livestock Production Research2019 Annual Report
The long-term objective is to improve understanding of forage-based production systems and genetics that allow ruminant livestock to efficiently consume and convert feedstuffs, primarily forages. Specifically, during the next five years we will focus on the following objectives. Objective 1: Evaluate nutrient-use and production efficiency in reproductive and terminal beef cattle within conventional and unconventional production systems in the Southern Great Plains (SGP). • Sub-objective 1A: Determine the relationship between frame score and calf growth rate, carcass quality, and economic returns under different finishing systems. • Sub-objective 1B: Evaluate traditional and novel annual grain crops for their efficacy as forages within beef production systems used in the SGP. • Sub-objective 1C: Determine the relationship between Residual Feed Intake (RFI) evaluations conducted in growing heifers and those conducted again in the same animals as mature cows within the SGP. • Sub-objective 1D: Characterize rumen metagenome and metabolome in relation to animal nutrient-use/production efficiency in beef cattle consuming forage and forage-grain diets. Objective 2: Determine the impact of management and animal genetics on health and stress related indices, and beef quality. • Sub-objective 2A: Determine the impact of finishing system (pasture versus confinement) on animal stress level indicators, and end product. • Sub-objective 2B: Evaluate the impact of cow management system on temperament and productivity in range cows and their offspring. Objective 3: Determine relationships between genetic/genomic characterizations in beef cattle and: a) the environmental and managerial responses, and b) the production phases. • Sub-objective 3A: Characterize environmental, managerial, and sire impacts on production responses within contemporary groups of cattle. • Sub-objective 3B: Evaluate the relationships between genetic markers of the rumen biome and key responses during the production phases.
Over the last 50 years, annual U.S. beef production has increased with fewer cows in the national herd by harvesting larger animals. This is due in part to availability and use of low-priced, abundant feed grains. While feed costs represent the single largest expense in beef production, less than 20% of the post-weaning feed energy consumed is converted to edible product. As competition and the price of feed grains increases due to growing global human population, use of grains for energy production, and other uses, beef production enterprises may need to transition from greater grain dependency to greater reliance on forage resources (pasture and rangeland) produced on lands not suitable for more intensive crop production. We propose to improve the efficiencies and sustainability of conventional forage-based components of beef production systems by development of more efficient management systems. In addition, identification of animal genetics best adapted to forage-based production systems in the Southern Great Plains (SGP) will aid in understanding how to reduce animal stress in management systems. The end result will be improved efficiencies of beef production with less grain and fossil fuel inputs, less need for capital through increased use of on-farm products, and increased competitiveness and profitability for producers. To accomplish this goal, the interactions of animal genetics, nutrient-use, health, and the beef system components must be understood to best match the animal resource with the forage resource. There is also a need to understand some of the ecological benefits and impacts of forage-based components of forage-based beef production systems.
Two mixed species warm-season forage stands were seeded as scheduled for grazing beef calves (Objective 1, Sub-objective 1A); however, exceptional rainfall events occurred immediately following seeding (2019 total rainfall occurring prior to July 2019 exceeded the yearly overall average by 3 inches) which resulted in one stand being flooded out while the other stand was excessively infested with multiple weedy plants. Therefore, the grazing experiment could not be conducted this year and will proceed in FY2020. ARS researchers in El Reno, Oklahoma, and university collaborators began investigating the capacity of a range of underutilized grain crops from India, the Middle East, Africa, Central and South America for their capacity to grow in the southern Great Plains and provide high quality forage (Objective 1, Sub-objective 1B). There were no milestones to be reported in FY2019; however, several of the projects in this Sub-Objective 1B are ahead of schedule. ARS researchers at El Reno, Oklahoma, in collaboration with researchers at Oklahoma State University, continued a 4-stage experiment to test the capacity of cultivars of novel (to the United States) grain legumes and cereal grasses to produce forage, and their forage value to cattle. The first stage of the Sub-objective 1B was completed (FY2018), and stage 2 (FY2019) is in the second of three years. Preliminary results noted a number of grain legume and grass cultivars from regions in Africa, India, Arabian Peninsula, Pakistan, and Afghanistan with large capacities to produce high quality forage in Oklahoma during late summer. The experiments to determine residual feed intake utilizing mature cows (Objective 1, Sub-objective 1C) will begin this fall and continue through the spring of 2020. Under a Standard Cooperative Agreement with researchers at Texas A&M AgriLife Research at Vernon, Texas, a Post-Doctoral Research Associate was hired to begin rumen microbiome research efforts related to cow size nutrient-use efficiency (Objective 1, Sub-objective 1D). Establishment of warm-season forage stands for forage finishing the beef calves failed due to flooding (Objective 2, Sub-objective 2A); the experiment will proceed in FY2020. Research is continuing to evaluate the impact of cow management systems on temperament and productivity in range cows and their offspring (Objective 2, Sub-objective 2B) with second year data collection occurring on schedule. A Beef Grand Challenge collaborative research plan with ARS researchers at Clay Center, Nebraska, and Miles City, Montana, was initiated in the fall 2018 (Objective 3, Sub-objective 3A and 3B) and performance data and blood samples and rumen samples for rumen microbiome linkages were collected during the stockering phase on winter wheat pasture and the finishing phase on a feedlot ration. This project integrates novel genomic approaches to enhance knowledge of the bovine genome, improve genetic merit of purebred and crossbred beef cattle, and improve beef cow energetic efficiency, especially related to grazing and high forage based diets in order to evaluate genetics x management x production environment interactions.
1. Effect of frame size on enteric methane and carbon dioxide production. Effect of beef cow frame size on enteric methane and carbon dioxide production. Researchers at El Reno, Oklahoma, evaluated the effect of frame size on enteric methane and carbon dioxide production in lactating Angus cows grazing native tall-grass prairie in central Oklahoma: Summer season. Methane is considered to be one of the major greenhouse gases, thus being a major contributor to global warming. In ruminants, enteric methane is a necessary byproduct of fermentation within the symbiotic relationship between rumen microbes and the ruminant host. The most efficient cow size for use in grazing systems has long been debated. Large-frame cows weighed 128 kg more and weaned a calf that was 39 kg heavier than medium-framed cows. There was no difference in amount of cow methane or carbon dioxide produced during the summer per kg of calf weaned. This finding suggests that both cow types are equally efficient at producing calves relative to enteric greenhouse gas production. Further research is needed to evaluate the impact of cow frame type on enteric gas production during other seasons of the year. Information will benefit cattle producers and researchers selecting and breeding cattle to be more economically efficient for reproductive performance.
Ma, S., Zhou, Y., Gowda, P.H., Chen, L., Steiner, J.L., Starks, P.J., Neel, J.P. 2019. Evaluating the impacts of continuous and rotational grazing on tallgrass prairie landscape using high spatial resolution imagery. Agronomy. 9(5):238. https://doi.org/10.3390/agronomy9050238.
Baath, G.S., Northup, B.K., Gowda, P., Turner, K.E., Rocateli, A.S. 2018. Mothbean: A potential summer crop for the Southern Great Plains. American Journal of Plant Sciences. 9(7):1391-1402. https://doi.org/10.4236/ajps.2018.97101.
Baath, G.S., Northup, B.K., Rocateli, A.C., Gowda, P.H., Neel, J.P. 2018. Forage potential of summer annual grain legumes in the southern Great Plains. Agronomy Journal. 110(6):1-13. https://doi:10.2134/agronj2017.12.0726.
Neel, J.P., Moriasi, D.N., Brown, M.A., Belesky, D.P. 2019. Model predicted DMI, nitrogen (N) excretion and N use efficiency utilizing plasma urea nitrogen (PUN) versus values estimated in conjunction with viable dry matter intake estimates in lambs grazing pasture. Journal of Animal Science and Research. 3(1). https://doi.org/10.16966/2576-6457.123.
Neel, J.P., Swecker Jr., W.S., Brown, M.A. 2019. Comparison of ultrasound and actual beef carcass measurements as influenced by stockering performance and finishing system. Journal of Animal Science and Research. 3(2). https://doi.org/10.16966/2576-6457.128.
Starks, P.J., Steiner, J.L., Neel, J.P., Turner, K.E., Northup, B.K., Gowda, P.H., Brown, M.A. 2019. Assessment of the standardized precipitation and evaporation index (SPEI) as a potential management tool for grasslands. Agronomy. 9(235). https://doi.org/10.3390/agronomy9050235.
Neel, J.P., Turner, K.E., Coleman, S.W., Brown, M.A., Gowda, P.H., Steiner, J.L. 2019. Effect of frame size on enteric methane (CH4) and carbon dioxide (CO2) production by lactating beef cows grazing native tall-grass prairie pasture in central Oklahoma, USA I: Summer season. Journal of Animal Science and Research. 3(3): https://doi.org/10.16966/2576-6457.130.