crude protein – Livestock and Poultry Environmental Learning Community

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Why Study Ammonia Emitted from Feedlots?

Ammonia volatilization is a major component of the nitrogen balance of a feedyard, and the effects of ammonia loss range from the economic (loss of manure fertilizer value) to the environmental (air quality degradation, overfertilization of ecosystems). Although not yet regulated, ammonia emissions from cattle are required to be reported under the Emergency Planning and Community Right to Know Act. Emission factors are used to estimate ammonia emissions for purposes of reporting and national inventories, but current emission factors are based on limited data. Our objective was to definitively quantify ammonia emissions and emission factors from commercial feedyards on the southern High Plains of Texas.

A typical feedyard on the High Plains of Texas. In the foreground, cattle in corrals with a stocking density of about 150 sq. ft./animal. In the background on the left, the runoff water retention pond, and center, a mound of stockpiled manure.

What Did We Do?

Ammonia emissions were quantified at three commercial feedyards in the Texas Panhandle from 2002 to 2008 using micrometeorological methods. Seasonal, intensive measurement campaigns were conducted from 2002 to 2005 at one feedyard, and ammonia emissions were near-continously monitored from 2007-2008 at two more feedyards. Meteorological and cattle management data were also collected.

What Have We Learned?

Ammonia emissions followed a distinct annual pattern. Emissions during summer were about twice those during winter, while spring and autumn emissions were intermediate. Annualized ammonia emissions ranged from 0.20 to 0.37 lb NH₃/animal/day, and averaged 0.26 lb NH₃/animal/day over all studies. Ammonia loss as a fraction of nitrogen fed to cattle averaged 41% during winter and 69% during summer; on an annual basis, 54% of fed nitrogen was lost as ammonia. Greatest emissions were observed when crude protein in cattle rations exceeded the nutrient requirements of beef cattle. Mean monthly ammonia emissions were strongly correlated with mean monthly temperature, and the relationship can be used to predict ammonia emissions from southern High Plains feedyards. Cattle feeders that meet recommended crude protein in rations can expect to lose half of fed N as ammonia. We recommend an annual emission factor of 88 lb/head for beef cattle feedyards based on one-time capacity, or 39 lb/head fed, based on a 150-d feeding period.

The annual pattern of ammonia emission rates (ER) followed seasonal temperatures, but also was sensitive to dietary crude protein (CP). Adding distillers grains to rations from March, 2008 to October, 2008 increased crude protein at Feedyard A to as high as 19%. Ammonia emissions greatly increased compared with the previous year and compared with Feedyard E.

Future Plans

Next steps involve using the extensive database from this research to adapt and refine process-based models of ammonia emissions. These models, based on the actual physical and chemical processes that control ammonia loss, will be more generally applicable than emission factors to a wider range of feedyards.

On an annual basis, ammonia emission averaged 0.26 lb per animal per day across the three feedyards and six years of study. Increased ammonia emission at Feedyard A in 2008 was due to high dietary crude protein when distillers grains were added to rations. Using these data and other estimates of ammonia loss from retention ponds and stockpiles, we recommend, for beef cattle fed a diet that meets protein requirements, an annual emission factor of 88 lb/head based on one-time capacity, or 39 lb/head fed, based on a 150-d feeding period.

Authors

Richard W. Todd, Research Soil Scientist, USDA-ARS Conservation and Production Research Laboratory, Bushland, Texas, richard.todd@ars.usda.gov

Richard W. Todd, Research Soil Scientist; N. Andy Cole, Research Leader and Research Animal Scientist (Nutrition); and Heidi M. Waldrip, Research Soil Scientist: USDA-ARS Conservation and Production Research Laboratory, Bushland, Texas.

Additional Information

Cole, N.A., R.N. Clark, R.W. Todd, C.R. Richardson, A. Gueye, L.W. Greene, and K. McBride. 2005. Influence of dietary crude protein concentration and source on potential ammonia emissions from beef cattle manure. J. Anim. Sci. 83:722 731.

Cole, N.A., A.M. Mason, R.W. Todd, M. Rhoades, and D.B. Parker. 2009. Chemical composition of pen surface layers of beef cattle feedayrds. Prof. Anim. Sci. 25:541-552.

Flesch, T.K., J.D. Wilson, L.A. Harper, R.W. Todd, and N.A. Cole. 2007. Determining ammonia emissions from a cattle feedlot with an inverse dispersion technique. Agric. For. Meteorol. 144:139-155.

Hristov, A. N., M. Hanigan, A. Cole, R. Todd, T. A. McAllister, P. M. Ndegwa, A. Rotz. 2011. Ammonia emissions from dairy farms and beef feedlots: A review. Can. J. Anim. Sci. 91:1-35.

Preece, S.L., N.A. Cole, R.W. Todd, and B.W. Auvermann. 2012. Ammonia emissions from cattle-feeding operation. Texas A&M AgriLife Extension Bulletin E-632 12/12.

Rhoades, M.B., D.B. Parker, N.A. Cole, R.W. Todd, E.A. Caraway, B.W. Auvermann, D.R. Topliff, and G.L. Schuster. 2010. Continuous ammonia emission measurements from a commercial beef feedyard in Texas. Trans. ASABE 53:1823-1831.

Sakirkin, S.L., N.A. Cole, R.W. Todd, and B.W. Auvermann. 2011. Ammonia emissions from cattle-feeding operations. Part 1: issues and emissions. Texas Agricultural Experiment Station Bulletin, Air Quality Education in Animal Agriculture, Issues: Ammonia, December, 2011. p. 1-11.

Sakirkin, S., R.W. Todd, N.A. Cole, and B.W. Avermann. 2011. Ammonia emissions from cattle-feeding operations. Part 2: abatement. Texas Agricultural Experiment Station Bulletin, Air Quality Education in Animal Agriculture, Issues: Abatement, December, 2011. p. 1-11.

Todd, R.W., N.A. Cole, and R.N. Clark. 2006. Reducing crude protein in beef cattle diet reduces ammonia emissions from artificial feedyard surfaces. J. Environ. Qual. 35:404-411.

Todd, R.W., N.A. Cole, M.B. Rhoades, D.B. Parker, and K.D. Casey. 2011. Daily, monthly, seasonal and annual ammonia emissions from southern High Plains cattle feedyards. J. Environ. Qual. 40:1-6.

Todd, R.W., N.A. Cole, H.M. Waldrip, and R.M. Aiken. 2013. Arrhenius equation for modeling feedyard ammonia emissions using temperature and diet crude protein. J. Environ. Qual. 2013. (accepted for publication).

Acknowledgements

Research was supported by CSREES Grant #TS2006-06009 under the direction of Dr. John Sweeten, Resident Director, Texas A&M University AgriLife Research and Extension Center, Amarillo, TX. Larry Fulton, Research Technician, USDA-ARS-CPRL, provided invaluable technical and logistical support and expertise.

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2013. Title of presentation. Waste to Worth: Spreading Science and Solutions. Denver, CO. April 1-5, 2013. URL of this page. Accessed on: today’s date.

Ammonia Emissions and Emission Factors: A Summary of Investigations at Beef Cattle Feedyards on the Southern High Plains from LPE Learning Center

Abstract

The Feed Assessment Tool (FEAST) was used to characterize the farming and livestock system in Limu-Bibilo district in Ethiopia. Prior to data collection, a Sustainable Livelihoods Framework (SLF) was conducted in August 2012. The quantitative data from individual interviews of 18 farmers were entered and analyzed using FEAST. Livestock production is an integral component of the farming system of the study area. Cattle are kept for food, cash, draught power and manure production. For the above average group grazing, crop residues, and cultivated fodder contributes 49%, 25% and 12% to the dry matter (DM) content of the total diet respectively. Similarly, grazing, crop residue, and purchased feeds contributes 33%, 23% and 20% of the DM respectively as to the below average groups. Grazing, crop residues and cultivated fodders are the major feed resources that are contributing 49%, 20%, and 14% of the metabolizable energy (ME) respectively as to the above average group and 32%, 17% and 14% respectively to the below average group. For above average group Grazing, cultivated fodder, purchased feeds, and crop residues contribute 42%, 17%, 16%, and 15% crude protein (CP) content respectively whereas purchased feeds, grazing, and cultivated fodders contribute 35%, 25%, and 15% of CP in the total diet in the case of below average groups. The problems that were raised by the farmers encompass, shortage of feed, scarcity of water, unavailability of cash or credit services, shortage of veterinary service, lack AI service, awareness and communication gap. In light of the problems the study recommends the development of herbaceous forage legumes and fodder trees species which can mitigate the constraints of feed scarcity. Training on cost effective livestock ration formulation techniques to reduce the feed shortages observed must be part of a strategy which requires attention to improve the production of the sector.

Why Study Feed Resource Availability?

The study area Lemu-Bilbilo district is located in Arsi zone in Oromia regional state of Ethiopia. It is characterized by a crop-livestock mixed farming system where dairy production contributes significantly to livelihoods of the smallholder farmers. Market-oriented dairy production based on crossbred dairy cows is also practiced in the district. However, economic benefits accruing from the livestock sector are not significant. Livestock production is constrained by ecological, technical and economic limitations which result in severe feed shortages. Thus, the objective of the current study was to assess feed resource availability and utilization using a feed assessment tool (FEAST) within the context of the overall farming and livestock production systems and to determine the potential of site-specific feed interventions in Lemu Bilbilo district.

What Will Be Learned In This Presentation?

The feed resources in the study area was primarily natural pasture, crop residue (cereals and legumes), purchased feed, cultivated fodder and naturally occurring and collected fodder. Crop residue was a major component in the diet of livestock. Animals rely on crop residues throughout the year especially when grazing pastures are scarce. Farmers who do not have adequate quantity of crop residue from cropping activities purchase additional straw from other farmers who produced cereals in surplus. The straw was usually fed to the animals without any form of processing or manipulation prior to feeding. However, some farmers were aware of mixing straws with linseed cake, wheat bran or salt as a means of improving quality and palatability. The contribution of grazing to dry matter (DM), metabolizable energy (ME) and crude protein content (CP) was relatively high for the above average group farmers who reserve more land for grazing pasture through land renting. Due to limitations of grazing and crop residue resources, farmers in the below average group were forced to purchase feeds. Purchased feeds thus contribute relatively higher to the DM, ME and CP of their livestock diets compared to that of the above average farmers. Feed shortage was identified by both groups of farmers as the most important problem of livestock production. Other constraints like water problem, inefficient veterinary and AI services were similar and equally important for farmers in both groups.

Silage pit in AMAE which was used as training ground for practical feed formulation techniques

Presenters

Presenters: Mesay Yami1, Bedada Begna1, TeklemedihinTeklewold1, Jane Wamatu 2, Peter Thorne 3 and Alan Duncan

1Ethiopian Institute of Agricultural Research (EIAR), Kulumsa Agricultural Research center, Socio-economics, extension Research Process, P. O. Box 489, Assela, Ethiopia: 2 International Center for Agricultural Research in the Dry Areas (ICARDA), Associate Scientist – Animal Nutritionist,: 3Crop Livestock Scientist, International Livestock Research Institute (ILRI), P.O .Box 5689, Addis Ababa, Ethiopia:

*Corresponding author E-mail: mesay44@gmail.com