Evaluation of Health Benefits of Conjugated Linoleic Acid (CLA)-Enriched Dairy and Beef Foods

Project Overview

Project Type: Research and Education
Funds awarded in 2004: $150,000.00
Projected End Date: 12/31/2007
Region: North Central
State: Iowa
Project Coordinator:
Teresa Steffens
Resource Conservation and Development for Northeast Iowa, Inc

Annual Reports


  • Agronomic: barley, grass (misc. perennial), hay
  • Animals: bovine
  • Animal Products: dairy


  • Animal Production: feed formulation, free-range, feed/forage
  • Crop Production: cover crops
  • Education and Training: farmer to farmer, on-farm/ranch research, participatory research
  • Farm Business Management: feasibility study
  • Sustainable Communities: partnerships, urban/rural integration

    Proposal abstract:

    Conjugated linoleic acid (CLA) is a unique fatty acid that is present in ruminants and many foods derived from them. This nutraceutical has attracted considerable recent attention because of its demonstrated health benefits in animal models of humans and in humans. Even though additional research is required, current evidence suggests that it is prudent for humans to increase consumption of CLA for improved health and longevity. Our ongoing SARE-supported research clearly demonstrates that the CLA concentration in bovine milk and beef is elevated 2- to 10-fold by grazing cattle on pastures. At a recent discussion with several of the participating farmers, this question was asked: What is the most logical follow-up experiment to the current one? The resounding response was “We need to determine the health effects of our CLA-enriched milk and beef on humans.” Hence, we propose the following experiment that is based on the hypothesis that eating the CLA-enriched foods will impact positively several measures of human health. Dairy and beef producers in Northeast Iowa who have demonstrated production of CLA-enriched milk and beef from grazing cattle will be selected for milk and beef food production. Milk and beef will be processed into several foods. These CLA-enriched foods and their commercial counterparts that are much lower in CLA content will be fed to free living young adults. Several measures of human health, including cholesterol, lipoproteins, CLA, glucose, insulin, glucagon in blood, bone density, body weight and composition, and glucose tolerance will be quantified. Results of this study will be published in the scientific and popular literature. It will be distributed at field days, and local, state, and regional meetings so that farmers may use the information for marketing their CLA-enriched and value-added products.

    Project objectives from proposal:

    This project will conduct an experiment that evaluates CLA-enriched dairy and beef foods from farmers on contract with CROPP. The farmers will use grazing systems to raise livestock and produce dairy products with high CLA content for the experiment. The milk and beef they produce will be processed and then prepared to create several different foods that will be incorporated into typical U.S. diets for a human feeding study. The study then will examine the health benefits of humans consuming CLA-enriched dairy and beef foods by evaluating the effect of feeding diets containing these CLA-enriched foods on concentration of cholesterol, individual lipoproteins, glucose, glucagon, and insulin in blood plasma, bone density, body weight and composition, and glucose tolerance. Results will be widely distributed through publication, field days and presentations. Several positive project outcomes are expected. Short-term outcomes of the project will enhance the quality of life for participants and encourage sustainable agricultural systems. Specific short-term outcomes include: Improved human health, quantified through the direct effects of CLA-enriched foods on measures of human health. Because pasture feeding is the management system found to produce CLA-enriched foods, (outcome of our current SARE-funded project), intermediate outcomes of this research will improve the profitability for farmers that utilize sustainable management systems including: Greater economic viability for dairy and beef producers that use sustainable high CLA pasture systems. Once the benefit to humans is demonstrated, high CLA content meat and dairy products are expected to increase in market value. Therefore, producers using the sustainable, high CLA pasture system, will be able to obtain a premium price in new and emerging markets and increase the market share for high CLA content pasture-fed animals. The long-term outcomes of this project will enhance the quality of life for farmers and ranchers, rural communities, and society as a whole by providing a better understanding of CLA as an indicator that links healthy lands and healthy animals to healthy humans. Long-term benefits will include: Improved health of the land and of human communities. This will be accomplished through a demonstration of the economic, environmental, and health justifications of management systems that result in greater utilization of pasture-based feeding systems for production of animal-derived foods on marginal land. Context, Background, and Rationale: This project assumes that individual practices that make agriculture more sustainable not only include scale, structure, and systems, but also include the markets and marketing that support those systems, scales, and land communities. The project is geared towards a better understanding of a food component, CLA, with potential to significantly improve the value and size of the market for animal products produced using sustainable, management intensive grazing systems. It is expected to provide a better understanding of the link between sustainable grazing systems and human health. Management of intensive grazing, through its emphasis on rotations and careful forage monitoring, corrects the principal grassland problem of overgrazing while maintaining the wide array of ecological advantages it has over confinement systems. As the animals collect the majority of their own feed and distribute their own waste, the system avoids the negative impacts of high-energy use (e.g., traction and chemicals), soil quality degradation (e.g., repeated tillage and farm chemicals), and water quality degradation (soil erosion, farm chemicals, and the perennial threat of manure lagoon spills) prevalent in modern livestock confinement systems. Grazing systems also increase rather than deplete soil carbon stores, are much friendlier to wildlife, are a wise use of rolling lands (highly erodible land from the Driftless area to the Piedmont, and are amenable to a smaller scale, family-centered agriculture. The natural behavior and biology of ruminants includes grazing, and the sustainability of grazing systems is reflected in USDA’s recently published national organic standard’s grazing requirement for ruminant livestock. The Upper Midwest has been subject to national trends towards an increasing number of large scale livestock confinements and a loss of small to medium dairy and beef operations that utilize grazing systems for production. There has been growing interest from the remaining small to medium dairy and beef producers to increase their profits through intensive grazing systems that utilize limited pasture ground for increased herd size and production. For example in Wisconsin, roughly half of all new dairies are going the route of management intensive grazing rather than confinement systems. The environmental and economic benefits of grazing systems could be further enhanced by the determination of the benefits of the end products to the consumer. This project was proposed by local producers/grazers after the preceding SARE study documented the high CLA content in milk and beef of pastured animals. Concentrations of CLA are much higher in ruminants than in nonruminant animals, and CLA content of milk and beef is much greater in grazing cattle than in cattle fed stored feeds when raised in confinement systems. The producers involved with this project see CLA as a tool to differentiate and increase the market value and market share for their products. Conjugated linoleic acid is already a desired food component among many health-conscious consumers; it is already possible for consumers to purchase CLA in capsule form. Conjugated linoleic acids helps prevent cancer, prevent heart disease, decrease obesity, and improve bone health and glucose tolerance in laboratory animals and is speculated to have the same results in humans. As consumers increase consumption of CLA-enriched foods for improving the healthfulness of their diets, the economics and sustainability of livestock production based on grass in the Upper Midwest and beyond could benefit greatly. Consumption of typical diets results in intakes of about 150 mg of CLA daily. Replacing the dairy and beef foods with CLA-enriched foods from cattle grazing grass would provide 200 mg or more of additional CLA, which is hypothesized to provide noticeable health benefits to humans. If grazers are attempting to eventually get paid bonuses for high-CLA milk and to direct-market high-CLA meats, they need to know the effects of consuming CLA-enriched dairy and beef foods on measures of human health. This question is the principal focus of this proposed project. As a major participant in this project, the Cooperative Regions of Organic Producers Pools (CROPP-Organic Valley) will help the producers answer these questions by processing the meat and dairy products. CROPP is now the largest organic producers' cooperative in the country with over 500 family farm members in 17 states. CROPP sales overall increased 70% over a recent two-year period, and organic milk sales increased 300% during that time. CROPP has found, from direct sales and from their retail customers, that consumers are looking for healthy food produced sustainably from humanely treated livestock. CROPP will be able to utilize the information gathered from this study to promote the high-CLA products of their members. By using milk and meat from producers who have participated in our currently funded SARE project, CROPP will process butter, ice cream, powdered milk, and cheeses and beefsteaks and hamburgers that have significantly greater CLA content (more than two times) than control foods. These foods then can be incorporated into typical diets of human subjects for evaluation of effects on human health. This project will contribute to all of NCR-SARE’s broad-based outcomes and impact sustainable agriculture in the North Central Region. The NCR SARE’s program benefits the environment by supporting research that provides information to promote sustainable grazing systems that result in soil conservation, improved water quality, and healthier landscapes. The project will add value to milk and beef products raised through pasture-based system and increase market share to increase farmer/rancher profitability. This project strengthens rural communities by providing options for small to medium dairy and livestock production systems to stay in business by increasing profitability. Each 400-cow dairy operation in northeast Iowa is estimated by Iowa State University to bring in over 16 jobs and nearly $600,000 to local communities each year. The sustainability of these dairies, as well as cattle operations, is dependent on the value of the product they produce. This potential increased value makes this project important to the viability of the rural communities by sustaining the small and medium production systems that provide substantial cash flow. This project also will impact sustainable agriculture in the North Central Region by providing documentation and education that will increase the demand for CLA-enriched food products that are derived from pasture management systems.

    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.