Location: Forage and Livestock Production Research
2020 Annual Report
Objectives
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.
Approach
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.
Progress Report
(Objective 1, Sub-objective 1A) Evaluation of finishing system using forages continues. (Objective 1, Sub-objective 1B). There were no milestones to be reported in fiscal year (FY) 2020; however, several of the projects in this Sub-Objective 1B are ahead of schedule. The goal is to search for functional annual forages for the Southern Great Plains among novel annual legumes and grasses that are traditionally grown for grain in order to identify species or cultivars that can provide high quality forage for improved animal performance during the summer grazing season. ARS researchers at El Reno, Oklahoma, with collaborators at Oklahoma State University, continued to test the capacity of cultivars of novel (to the United States) grain legumes and cereal grasses to produce forage, and assess their forage value to cattle. The second stage of the Sub-objective (1B.2) has been completed and samples were prepared to examine the function of these novel forages in the rumen of cattle, as part of Stage 3 (1B.3). Research compared the capacity of the novel legumes guar and tepary bean to serve as high quality forage during late summer. Other research reported on combining near infrared reflectance spectroscopy and machine learning techniques to improve the definition of different attributes of forage quality in four legumes. (Objective 1, Sub-objective 1C) A second year evaluating Cow Residual Feed Intake will begin in the fall of 2020, and continue through the spring of 2021. (Objective 1, Sub-objective 1 D) In collaboration with researchers at Texas A&M AgriLife Research at Vernon, Texas, a Post-Doctoral Research Associate continues rumen microbiome research efforts related to cow size and nutrient-use efficiency. A grazing project was initiated to monitor changes in rumen microbiome ecology during the growing season as steers graze a native warm-season grass pasture that was controlled burned in the spring. (Objective 2, Sub-objective 2A) Research continues to evaluate confinement- and pasture-finishing impacts on animal stress (cortisol) during the finishing period. (Objective 2, Sub-objective 2B) Research is continuing to evaluate the impact of cow management systems on temperament and productivity in range cows and their offspring. (Objective 3, Sub-objective 3A and 3B) A Beef Grand Challenge collaborative research plan with ARS researchers at Clay Center, Nebraska, and Miles City, Montana, continues for the second year with performance data collected; blood samples and rumen samples for rumen microbiome linkages were collected during the early stockering phase on winter wheat pasture and the finishing phase on a feedlot ration. A planned collection of blood and rumen samples for rumen microbiome linkages were not collected during the late stockering phase on winter wheat pasture due to COVID-19 pandemic. 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.
Accomplishments
1. Initial laboratory results show impacts of supplemental forages and feedstuffs on cattle rumen ecology. Researchers at El Reno, Oklahoma, along with collaborators used DNA fingerprinting to profile changes to bovine rumen ecological populations (bacteria, archea, protozoa, and fungi) using different supplemental forages and feedstuffs in the laboratory. Excessive amounts of feedstuffs and sudden diet changes with limited adaptation time for rumen microbial populations is detrimental to maintaining cattle health. Nutritionists and producers typically provide supplemental feedstuffs and mixed rations to correct nutrient deficiencies for improved overall feed- and forage-use efficiency and improved animal growth, performance, and health, all aimed at improving economic returns. Results suggest that DNA fingerprinting of rumen ecology of bacteria, archea, and protozoa populations can identify pattern groupings of forages and feedstuffs in the laboratory. However, more research is needed on defining ecological groupings of a feedstuff having commonality with two or more of the bacterial, archeal, protozoal, and fungal groups. Rumen ecological grouping of forages and feedstuffs can help to better create forage mixtures and feedstuffs supplements (energy, protein, and a combination) for improved nutritional management in cattle.
Review Publications
Turner, K.E., Belesky, D.P., Zobel, R.W., Fortuna, A. 2020. Initial effects of supplemental forages and feedstuffs on bovine rumen ecology in vitro as determined by DNA-based molecular procedures. Journal of Applied Animal Research. 48(1):268-280. https://doi.org/10.1080/09712119.2020.1781648.
Baath, G.S., Northup, B.K., Gowda, P.H., Rocateli, A.C., Singh, H. 2020. Summer forage capabilities of tepary bean and guar in the southern Great Plains. Agronomy Journal. 112(4):2879-2890. https://doi.org/10.1002/agj2.20220.
Baath, G.S., Baath, H.K., Gowda, P.H., Thomas, J.P., Northup, B.K., Rao, S., Singh, H. 2020. Predicting forage quality of warm-season legumes by Near Infrared Spectroscopy coupled with machine learning techniques. Sensors. 20(3):867. https://doi.org/10.3390/s20030867.
Wagle, P., Gowda, P.H., Neel, J.P., Northup, B.K., Zhou, Y. 2020. Integrating eddy fluxes and remote sensing products in a rotational grazing native tallgrass prairie pasture. Science of the Total Environment. 712:136407. https://doi.org/10.1016/j.scitotenv.2019.136407.
Kandel, T.P., Gowda, P.H., Northup, B.K. 2020. Influence of tillage systems, and forms and rates of nitrogen fertilizers on CO2 and N2O fluxes from winter wheat cultivation in Oklahoma. Agronomy. 10(3):320. https://doi.org/10.3390/agronomy10030320.
Wagle, P., Skaggs, T.H., Gowda, P.H., Northup, B.K., Neel, J.P. 2020. Flux variance similarity-based partitioning of evapotranspiration over a rainfed alfalfa field using high frequency eddy covariance data. Agricultural and Forest Meteorology. Vol. 285-286. https://doi.org/10.1016/j.agrformet.2020.107907.
Wagle, P., Gowda, P.H., Billesbach, D., Northup, B.K., Torn, M., Neel, J.P., Biraud, S. 2020. Dynamics of CO2 and H2O fluxes in Johnson grass in the U.S. Southern Great Plains. Science of the Total Environment. 739:140077. https://doi.org/10.1016/j.scitotenv.2020.140077.
Steiner, J.L., Wetter, J.T., Robertson, S.D., Teet, S.B., Wang, J., Wu, X., Zhou, Y., Brown, D., Xiao, X. 2020. Grassland wildfires in the Southern Great Plains: Monitoring ecological impacts and recovery. Remote Sensing. 12(4):619. https://doi.org/10.3390/rs12040619.
