Expanding the grazing season for sustainable year-round forage-finished beef production

Final Report for LS06-188

Project Type: Research and Education
Funds awarded in 2006: $163,000.00
Projected End Date: 12/31/2009
Region: Southern
State: South Carolina
Principal Investigator:
Susan Duckett
Clemson University
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Project Information

Abstract:

Forage-finished beef can be produced during fall, winter and spring months in the Southeastern U.S. through utilization of high quality cool season forages. However, forages for producing forage-finished beef during the summer months are more limited and the primary perennial forages, bermudagrass (Cynodon dactylon L. Pers.) and bahiagrass (Paspalum notatum Flugge), do not support high gains for finishing. Therefore, this study examined the effectiveness of several summer active forages to expand the harvest window of forage-finished beef. Sixty Angus-cross steers were finished on five summer forage species, chicory (Cichorium intybus L.; CH), alfalfa (Medicago sativa L.; AL), cowpea (Vigna unguiculata L.; CO), pearl millet (Pennisetum glaucum L.; PM), and bermudagrass (BG), to assess the effects of forage species on finishing steer performance, carcass quality, fatty acid composition and tenderness in a two-year study. Ten 2 ha paddocks were blocked and assigned forage species (2 reps per species/yr). Steers were randomly assigned to paddocks (n = 3/yr) and started grazing when adequate forage growth was available. Put and take grazing techniques were utilized. Steers were slaughtered when there was insufficient forage mass to support animal gains, or steer weight exceeded 591 kg. Average daily gains were greater (P < 0.05) for AL and CH than BG, CO, and PM. Total grazing days (d/ha) were greatest (P < 0.05) for PM and lowest for CO. Hot carcass weight was greatest (P < 0.05) for BG and CO and lowest for PM. Dressing percentage was higher (P < 0.05) for CO and AL than BG, CH, or PM. Warner-Bratzler shear force values were lower (P < 0.05) for AL and CO than BH, CH, or PM. Conjugated linoleic acid (CLA) and trans-11 vaccenic acid (TVA) concentrations were higher (P < 0.05) for PM and BG than AL, CH, or CO. Linoleic acid concentration was higher for CH than others. Linolenic acid concentrations were greater for CH and CO compared to AL, BG, and PM. The ratio of omega-6 to omega-3 fatty acids was higher (P < 0.05) for CH and PM than AL, BG, and CO. In summary, animal gains were highest (1.20 kg/d) for alfalfa and chicory. Steers grazing the legume species, alfalfa and cowpea, during finishing had higher dressing percentages and produced the most tender beef. Steers grazing the grass species, bermudagrass and pearl millet, had greater percentages of anticarinogenic compounds, CLA and TVA. This research project identified several viable forage species for finishing beef cattle in summer months. Palatability and composition of the beef products from steers finished on these forage species was highly acceptable and indicated nutritional benefits for forage-finished beef. Results of this research have been presented in multiple workshops, county agent trainings, and short courses across the Southeast. These trainings in combination with the demonstration plots have lead to adoption of these practices by numerous producers in Virginia, South Carolina, North Carolina, Florida, Georgia and Alabama.

Project Objectives:

1) Examine potential forage systems to expand grazing seasons for year-around forage-finished beef production.
2) Determine the effect of these various warm season forages on beef carcass quality, composition and palatability
3) Determine the profitability of these forage systems as compared to traditional marketing schemes.
4) Implement on-farm plots and experiment station field days to demonstrate results and deliver information to farmers.

Introduction:

The purpose of this project was to examine the effectiveness of several warm season forages for summer production of forage-finished beef. Forage-finished beef can be produced during fall, winter and spring months in the Southeastern U.S. through utilization of cool season forages like non-toxic tall fescue, wheat, rye, ryegrass, crimson clover, white clover and red clover. These forage species, planted either in monocultures or in combinations, frequently produce individual animal gains which exceed 1 kg/d. Unfortunately, crops for producing forage-finished beef in summer months are more limited. Bermudagrass (Cynodon dactylon L. Pers.) and bahiagrass (Paspalum notatum Flugge) are the primary forage species utilized in the Southeast for summer grazing. Although these perennial forages are well suited for traditional cow-calf operations of the region and can produce high yields, their nutrient content is inadequate for finishing beef cattle. Typical season-long stocker cattle gains are approximately 0.45 kg/d, which make them inadequate for finishing beef cattle. In addition, these grasses require nitrogen fertilization which has become increasingly expensive in recent years due to escalating natural gas prices. Research is needed to evaluate alternate forage crops for production of forage-fed beef during summer months. Annual and perennial forage crops including chicory (Cichorium intybus L.), alfalfa (Medicago sativa L.), cowpea (Vigna unguiculata L.) and pearl millet (Pennisetum glaucum L.) all have nutrient contents capable of producing adequate animal gains for summer forage finished beef production. These forages possess agronomic characteristics useful in the Southeast. Therefore, incorporating these forage crops into traditional grazing systems has the potential to improve animal performance, enhance enterprise profitability by producing a value-added product, and increase overall system sustainability by decreasing reliance on nitrogen fertilizers and/or weather problems.

Forage finished beef products have greater concentrations of nutraceutical compounds like conjugated linoleic acid, a potent anticarcinogen, and alpha-linolenic acid, an omega-3 fatty acid involved in lowering the risk of atherogenesis, compared to beef from traditional grain-finished cattle. These changes in beef composition with forage finishing are the result of the differences in fatty acid composition among forages and grains. Forages are high in alpha-linolenic (C18:3) acids and fat soluble vitamins like alpha-tocopherol and beta-carotene, and cattle consuming forages deposit more of these compounds in their tissues. The utilization of different forages during the summer months to expand the grazing season could alter the fatty acid composition, fat soluble vitamin content, and palatability of the resulting beef product. Grasses and legumes differ in fatty acid composition with legumes having typically higher concentrations of linoleic acid and lower levels of linolenic acid. Conjugated linoleic acid is a potent anticarcinogen that is produced in ruminant animals during the ruminal biohydrogenation of dietary linoleic acid. Beef cattle finished on pastures containing grasses and legumes have been shown to higher alpha-tocopherol and polyunsaturated fatty acids concentrations than those finished on grasses alone. Limited information is available on the fatty acid composition of these warm season forages or beef produced from finishing on these forages. Certain forage species have been shown to alter fatty acid composition and negatively impact acceptability in lamb. These factors are very important in producing a beef product that will be acceptable in palatability and maintain high levels of CLA and omega-3 fatty acids. Thus, it is important to ascertain the changes in beef quality with finishing on these various warm season forages to ascertain product acceptability.

Markets are expanding for animal products raised naturally on forage based systems with enhanced nutraceutical content. The ability to direct market meat products would allow producers to recapture more value using sustainable environmental practices and provide consumers with meat products containing greater health benefits. Currently there are limitations in providing a year-around supply of forage-finished beef, which limits marketing potentials and customer satisfaction. We evaluated various forages to expand the grazing season to improve forage production during the summer months, enhance animal performance and economic returns, and assessed changes in beef composition and consumer acceptability.

Cooperators

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  • John Andrae

Research

Materials and methods:

Objective 1: Examine potential forage systems to expand grazing seasons for year-around forage-finished beef production. One to two hectare pastures (2 replicates per treatment) were established to evaluate the effect of forage species on animal performance, grazing days, gain per unit land area, and forage quality parameters. Treatments consisted of the following forage species: 1) alfalfa, 2) chicory, 3) cowpea, 4) pearl millet, and 5) bermudagrass. These forages are adapted to broad areas of the Southeastern U.S. ranging from northern Florida to the Piedmont area of Virginia. Alfalfa and chicory were no-till established into killed bermudagrass sod in September. Cowpea was no-till established into bermudagrass sod in mid-late April. Pearl millet was established annually into clean tilled areas in mid to late April. Bermudagrass pastures are included for benchmark data as control treatments. Pastures were stocked with tester steers when summer forage production was adequate to maintain a minimum of three tester steers per paddock. Put and take stocking was utilized as needed to maintain appropriate forage allowance in each paddock. Animals were weighed at 28 d intervals throughout the study to determine gain per head and gain per hectare. Forage samples were clipped at a 2.5 cm height to determine forage availability and composition and grab samples were collected for analysis of crude protein, fiber content, and fatty acid composition using standard laboratory methodology.

Objective 2: Determine the effect of these various warm season forages on beef carcass quality, composition and palatability. Beef cattle finished on warm season forages (30 hd/year; 6 hd/forage treatment) as outlined in objective 1 were slaughtered at the Clemson University Meat Laboratory under state inspection at the completion of the grazing season. At 24 h postmortem, carcass data was obtained and longissimus muscle samples obtained for determination of total fatty acid content including conjugated linoleic acid and omega-3 fatty acids, tocopherol analysis, and beta-carotene analysis. Samples from the gluteus medius (top sirloin) were also obtained for consumer panel determination of acceptability.

Objective 3: Determine the profitability of these forage systems as compared to traditional marketing schemes. Risk-rated enterprise budgets on the forage based finishing systems were developed and compared to currently published UGA Risk-Rated Cow-Calf and Stockering budgets. The production and cost data for developing these budgets originated from forage research conducted in this study. Estimated returns were be calculated based on the results of the marketing survey conducted in this project.
Budget comparisons were made on returns above variable cost and returns above fixed cost. Cash flow projections were developed to include forage establishment cost, supplementation cost, cattle facilities cost, and cattle finishing cost from birth to harvest. These cash-flow projections were used to determine if the proposed program is feasible as well as estimating actual investment capital requirements and years to breakeven.

Objective 4: Implement on-farm plots and experiment station field days to demonstrate results and deliver information to farmers. Project participants include county extension agents in South Carolina and Georgia who are intensively trained in forage and livestock management. These agents are located in geographically diverse areas and are familiar with innovative farmers who are willing to apply new ideas on their farms. These agents were utilized to identify and oversee on-farm forage demonstrations so that farmers can be effectively reached in these areas. In addition, a statewide field day was conducted on the experiment station near the project end to deliver forage and animal production results to clientele. Results of this research were presented at several conferences throughout the Southeastern U.S.

Research results and discussion:

Average daily gain for the five forage treatments was highest (P < 0.05) for alfalfa (AL) and chicory (CH) and lowest (P < 0.05) for bermudagrass (BG), cowpea (CO), and pearl millet (PM). Average daily gain was above 1 kg/d for AL and CH treatments. Gain per hectare (kg/ha) was greatest (P < 0.05) for AL and lowest (P < 0.05) for CO. The number of days steer grazed each forage treatment was highest (P < 0.05) for BG and lowest (P < 0.05) for CO.
Hot carcass weights were heavier (P < 0.05) for AL, BG, and CO and lighter (P < 0.05) for PM. Dressing percentage was highest (P < 0.05) for CO and lowest (P < 0.05) for BG, CH, and PM. Dressing percentage for AL was also greater (P < 0.05) than BG, CH, or PM. Fat thickness was greater (P < 0.05) for AL, CH and CO and lowest (P < 0.05) for PM. Ribeye area, yield grade, and marbling score did not differ (P > 0.05) among the forage treatments. Quality grade was highest (P < 0.05) for CO and lowest (P < 0.05) for CH. Longissimus muscle color did not differ (P > 0.05) among the forage treatments. Subcutaneous fat color was lighter (P < 0.05) AL, CH, and PM than CO. However, yellowness of subcutaneous fat color did not differ (P > 0.05) among forage species.
Total fatty acid and cholesterol content of the longissimus muscle did not differ (P > 0.05) among forage species. Total saturated, odd-chain, monounsaturated, omega-6 and omega-3 fatty acid concentrations did not differ (P > 0.05) among forage species. Ratio of omega-6 to omega-3 fatty acids were higher for PM and CH than for AL, BG, and CO. The concentration of conjugated linoleic acid (CLA) was higher (P < 0.05) for PM and BG than AL, CH and CO. Concentrations of trans-11 vaccenic acid (TVA) was highest (P < 0.05) for BG and lowest (P < 0.05) for AL. Alpha-tocopherol content did not differ (P > 0.05) among forage species. Beta-carotene and retinol contents were highest (P < 0.05) for PM and lowest (P < 0.05) for CH.
Steaks from legume species, AL and CO, had lower (P < 0.05) shear force values than BG, CH or PM. Consumers rated overall palatability highest (P < 0.05) for AL and CO and lowest (P < 0.05) for BG and CH. Consumer preference was highest (P < 0.05) for AL and lowest (P < 0.05) for BG and CH.

Participation Summary

Educational & Outreach Activities

Participation Summary:

Education/outreach description:

Publications:
Duckett, S. K., J. G. Andrae, J. R. Schmidt, and M. C. Miller. 2009. EXPANDING THE GRAZING SEASON FOR SUSTAINABLE YEAR-ROUND
FORAGE-FINISHED BEEF PRODUCTION. Proc. of the National Conference on Grazing Lands, Reno, NV, Dec. 2009.

Andrae, J.G. 2008. Invited Symposium Speaker: Opportunities and obstacles for forage-based dairy and beef production in the Southeastern U.S. J. Anim. Sci. Vol. 86, E-Suppl. 2/J. Dairy Sci. Vol. 91, E-Suppl. 1. Pg. 309.

Schmidt, J. R., J.G. Andrae, S.K. Duckett, and M. Miller. 2009. Summer forage species alters animal performance, carcass characteristics and fatty acid composition of grazing beef steers. J. Anim. Sci. Vol 87 E-Suppl. 2 pg 224.

Duckett, S. K. and J. G. Andrae. 2009. Grass-fed management systems for profitable livestock production. J. Anim. Sci. 87 (E-Suppl. 2):345.

Schmidt, J. R., J. G. Andrae, S. K. Duckett, and M. C. Miller. 2009. Summer forage species alters animal performance, carcass characteristics and fatty acid composition of grazing beef steers. J. Anim. Sci. 87 (E. Suppl. 2):224.

Schmidt, J. R., J. G. Andrae, S. K. Duckett, M. C. Miller, S. E. Ellis. 2008. Forage species alters animal performance, carcass quality, and fatty acid composition of forage-finished beef produced in the summer months. J. Anim. Sci (E-Suppl. 2):536.

Journal Articles:
Schmidt, J., J. Andrae, S. Duckett, S. Ellis. Forage species effects performance, carcass characteristics and fatty acid profiles of forage-fed beef steers. In preparation for submission to J. Anim. Sci. Expected submission date Spring 2010.

Extension Bulletins:
Andrae, J., J. Barnes, and K. Campbell. 200X.Warm Season Legumes. Clemson University Forage Leaflet #XX. In review.

Proceedings:
Andrae, J. Forage crops for production of forage-finished beef in the Mid-Atlantic. 2007 Proceedings of Shenandoah Valley Agriculture Research and Education Center Field Day. Steele’s Tavern VA.
Andrae, J. Innovative forage production practices to improve summer weight gains. Proceedings of Virginia Pasture Cattle Conference. Staunton VA. January 23, 2008.
Andrae, J. Forage options to improve summer gains. Proceedings of Alabama Stocker Conference. Auburn, AL. August 14-15, 2008.
Andrae, John. Supplementation in pasture finishing systems. Proceedings of the 2009 Mid-Atlantic Grass-Finished Livestock Conference. Staunton VA. October 2009.

Abstracts:

Regional and In-State Popular Press Articles
Andrae, J. Forage Species to Improve Summer Weight Gains in the Southeast. National Cattleman. April 2008. Vol. 23 Issue 7. Circulation 33,000.
Andrae, J. Annual Warm Season Grasses. Carolina Cattle Connection. April 2008.
Andrae, J. Warm season forage legumes. Carolina Cattle Connection. June 2008.

DVD Releases:
Back to Reality Forage Finishing Conference. 4 DVD set of the regional conference held February 2009 in Columbia, SC. 150 copies.

Television Releases:
Forage finished beef and human health. WYFF News 4. Greenville SC. February 20, 2006.

Professional Society Papers
INVITED SYMPOSIUM SPEAKER: Opportunities and obstacles for forage-based dairy and beef production in the Southeastern U.S. 2008 ADSA/ASAS Annual Conference. Indianapolis, IN. July 7-11, 2008.
INVITED SYMPOSIUM SPEAKER. Forage Systems to Reduce Nitrogen Applications. J. Andrae and J. Prevatt. American Society of Animal Science Southern Section Meeting. February 1-3, 2009. Atlanta, GA.

Invitational Lectures Given at Extension Sponsored Programs:
Forage crops for production of forage-finished beef in the Mid-Atlantic. Shenandoah Valley Agriculture Research and Education Center Field Day. Steele’s Tavern VA. August 1, 2007. Approximately 150 attending.

Pasture species and management for forage-fed beef production. Orangeburg County Beef Production School. September 27, 2007. 16 attending.

Virginia Pasture Cattle Conference. January 23, 2008. Staunton VA. Innovative forage production practices to improve stocker cattle gain. Approx. 60 attending.

Mountain Beef Cattle Field Day. April 16, 2008. Blairsville, GA. Grass-Fed Beef: A Research Update. Approx. 40 attending.

Forage options to improve summer gains. Auburn University Stocker Conference. August 14-15, 2008. Auburn, AL.

Invitational Lectures Given to Non-Extension Professional Groups:
An update on forage-fed beef production systems. South Carolina Beef Board. May 3, 2006. Columbia SC.

SC Beef Board and Cattleman’s Executive Board Meeting. Video presentation highlighting Clemson University’s forage-fed beef research efforts. January 30, 2008.

Carolina Farm Stewardship Association Annual Conference. Anderson, SC. Summer forage options for finishing beef on pasture. November 1, 2008. 60 attending.

“Back to Reality” Forage Finishing Conference. “Forages for high gains in the Southeast”. February 12-13th, 2009. Columbia, SC. 35 attending.

“New and Neglected Forage Crops”. Alabama Forage and Grassland Council Meeting. Livingston AL. December 2009.

Duckett, S. K. 2009. Back to Reality Conference, Columbia, SC.
Duckett, S. K. 2009. Mid-Atlantic Grass-fed Beef Conference, Stauton, Virginia.
Duckett, S. K. 2009. Mid-Atlantic Grass-fed Beef Conference, Raleigh, NC.

In-Service Extension Agent Training:
Forage Update. South Carolina Agricultural County Agents Association Annual Meeting. June 15, 2006. Clemson SC.
General Forage and Livestock Training. May 30-June 1, 2007. Organized multiple field visits and arranged for registration and travel for 11 SC agents along with FL, GA and AL county agents to the 61st Southern Forage Crop and Pasture Improvement Conference in Tallahassee FL. Sites visited included demonstration plots associated with Southern SARE grant.
Developing forage systems that keep cattle gaining in hot weather. August 6, 2008. North Carolina State University In Service Training. Raleigh, NC. Delivered via webcast.

Local or County Educational Meetings:
Cherokee County Cattleman’s Association. February 15, 2007. Matching animal intake and nutritional needs to forages.
Saluda County Cattleman’s Association. April 12, 2007. Matching animal intake and nutritional needs to forages.
Oconee County Cattleman’s Association. May 8, 2007. Matching animal intake and nutritional needs to forages.
Union County Cattleman’s Association. May 17, 2007. Alternative forages for beef operations.
Fairfield County Cattleman’s Association. Species for finishing beef on pasture. January 8, 2009.

Field Days/Tours:
Hickory NC Cattlemans Association. August 2, 2006. Hosted tour of 35 producers at Simpson Research Station and gave overview of forage research projects.
Clemson University Cattle and Forage Field Day. June 9, 2007. Rembert SC. Traditional and alternative forage species for summer hay and grazing. Approx. 60 attending.
Edisto REC Fall Field Day. September 6, 2007. Grazing winter annual forages and producing forage fed beef. Approx. 150 in beef section
South Carolina Cattleman’s Association Field Day. April 26, 2008. Simpson Research Farm Pendleton SC. Organized field tour of research and gave presentations on forage-finishing project. Over 200 attending.

Demonstration Plots:
Plots of alfalfa, chicory, pearl millet and cowpea were established on farms in Madison County FL, Saluda County, SC, and Barnwell County, SC. These plots in addition to the research plots on the Clemson campus were utilized in multiple local producer and county Extension level pasture walks, field days and educational programs in addition to those listed above.

Project Outcomes

Project outcomes:

A major limitation to implementing forage fed beef in the Southeastern U.S. is the seasonality of production. Fall, winter and spring finishing can be accomplished by grazing several perennial and annual cool season grasses and legumes. Traditionally, forage systems in the Southeastern U.S. (particularly more southern areas) are warm-season perennial grass species which, although dependable and productive, are low in quality. These systems are extremely efficient in beef cow-calf operations, but cannot provide adequate gains for stocker or forage-finished beef production. Furthermore, bermudagrass and bahiagrass require nitrogen inputs which are typically fossil-fuel based. Costs of inorganic fertilizers have increased over the past 5 years and will likely be unsustainable economically and environmentally in future years. This research project identified several viable forage species for finishing beef catttle in summer months. Palatability and composition of the beef products from steers finished on these forage species was highly acceptable and indicated nutritional benefits for forage-finished beef. Results of this research have been presented in multiple workshops, county agent trainings, and shortcourses across the Southeast. These trainings in combination with the demonstration plots have lead to adoption of these practices by numerous producers in Virginia, South Carolina, North Carolina, Florida, Georgia and Alabama.

Economic Analysis

Cost per gain ($/kg) did not differ between treatments ranging from $1.71 per kg for alfalfa to $2.67 per kg for pearl millet. Pearl millet had the lowest and the only negative price for gross margin/ha (P < 0.05). This was due to lower carcass prices then the in-value for the steers at the beginning of the grazing period. Total cost of production was lowest for cowpea due to low fertilizer requirements, and highest for pearl millet because of high fertilizer requirements and annual establishment costs (P < 0.05). For all treatments, return over total costs (ROTC) was negative, with pearl millet having the greatest losses in ROTC (P < 0.05). Breakeven sales prices were highest for cowpea and pearl millet and lowest for alfalfa (P < 0.05).
The negative numbers for return over variable costs (ROVC) and ROTC and low prices for gross margin/ha compared to total and variable costs may not accurately represent a forage-finishing system. Carcass prices were estimated using traditional commodity markets. However, forage-finished beef can be sold as a value-added product as consumers are increasingly willing to pay a premium for products with perceived health and environmental benefits. Some producers are reporting receiving prices in excess of $200 per 45.4 kg for live animals for forage-finished beef. All breakeven sales prices for this study are well below premiums that producers could receive for forage-finished beef. These premiums would likely make all forage treatments profitable enterprises. Furthermore, in a year with normal rainfall, stocking rates would likely increase, which would increase gross margin/ha.

Farmer Adoption

Plots of alfalfa, chicory, pearl millet and cowpea were established on farms in Madison County FL, Saluda County, SC, and Barnwell County, SC. These plots in addition to the research plots on the Clemson campus were utilized in multiple local producer and county Extension level pasture walks, field days and educational programs in addition to those listed above. In addition, results of this project have been presented throughout the Southeast. These trainings in combination with the demonstration plots have lead to adoption of these practices by numerous producers in Virginia, South Carolina, North Carolina, Florida, Georgia and Alabama. We continue to receive requests for speaking engagements and publications on our research project.

Recommendations:

Areas needing additional study

This research project addressed grazing of five different forage species in monocultures. Binary or more complex mixtures of forage species need to be examined. This study also only examined the finishing period of forage-fed beef production. Additional research is needed to assess the impact of forage sequences on production, meat quality and composition. Finishing on legume species had a positive impact on palatability (increased tenderness) and further examination is warranted.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.