Omega-3 Purlsane Eggs

Project Overview

Project Type: Graduate Student
Funds awarded in 2007: $10,000.00
Projected End Date: 12/31/2008
Grant Recipient: North Carolina State University
Region: Southern
State: North Carolina
Graduate Student:
Major Professor:
Thomas Rufty
NCSU Crop Science Department

Annual Reports


  • Animals: poultry


  • Animal Production: feed/forage, feed rations, free-range, housing
  • Crop Production: cover crops, crop rotation, nutrient cycling, tissue analysis
  • Education and Training: demonstration, on-farm/ranch research
  • Farm Business Management: agricultural finance, new enterprise development, value added, whole farm planning
  • Production Systems: holistic management, integrated crop and livestock systems, organic agriculture

    Proposal abstract:

    Omega-3 fatty acids are essential to human health. Presently, the typical western diet does not provide adequate amounts of omega-3’s, and the primary sources for omega-3’s are limited and inconsistent with sustainability. For optimal nutritive benefit, humans must consume the long chain omega-3 form (DHA) generated in animals. Unfortunately, DHA is being supplied from sources like flax seed and wild-caught fish (e.g. salmon) that must be transported over long distances with large energetic and environmental costs. Also, demand for omega-3 is contributing to over-fishing and the fish can contain high levels of heavy metals. The plant common purslane (Portulaca oleracea L.), which grows widely as a weed in the southeastern U.S., may be an important new source of omega-3 fatty acids, as its omega-3 content is among the highest of any leafy plant. Though plants generally have been considered an inferior source of omega-3’s because they contain primarily short-chain forms (ALA), there is research evidence suggesting that hens fed purslane can convert short-chain ALA into long-chain DHA and produce eggs with high DHA content. In this project, I will investigate key elements of the purslane – laying hen system. The purpose will be to determine the potential yield of ALA when purslane is grown as a crop or forage, purslane growth responses and changes in ALA levels under environmental stresses, and amounts of DHA generated in egg production. Furthermore, using information from this research, I will assess the economic viability of implementing the system on a local, small farm scale.

    Project objectives from proposal:

    1. 1. Determine the phenotypic variation in ALA omega-3 fatty acids within purslane and how best to conserve ALA in processing. Purslane seeds will be collected from fields in the Coastal Plains, Piedmont, and Mountain regions of NC and purchased from commercial venues. Plants will be grown under favorable agronomic conditions in field plots. Leaf tissue samples will be analyzed when fresh and after drying at various temperatures to determine whether omega-3 levels differ and whether levels are affected by drying and heat. 2. Determine alterations in ALA content in purslane plants subjected to environmental stress. Plants from a selection of seed sources will be grown in controlled greenhouse and growth chamber conditions. Treatments will include water availability, fertility level, photoperiod, and temperature. Biomass production and omega-3 concentrations will be measured. 3. Identify appropriate cultural practices to maximize ALA production in the field. Studies will be conducted at two NCSU research stations: the Center for Environmental Farming Systems in Goldsboro, N.C., and the new organic farming unit at Lake Wheeler Field Laboratories in Raleigh. Seeds will be sown at varying times between March and September and at four different densities. Tissues will be harvested after 60 days, and biomass and ALA per area determined. 4. Evaluate the potential for purslane inclusion into the poultry diet and the effects of purslane on DHA omega-3 levels in eggs. Preliminary tests will determine hen preference for fresh purslane compared to conventional feed. Then, the nutritional acceptability of processed purslane inclusion into feed at various concentrations would be tested. Hen weight, egg production, omega-3 contents, and cholesterol levels will be analyzed, and a conversion efficiency value calculated. 5. Examine the effects of purslane inclusion in forage rotation on egg production and DHA accumulation in eggs. Forage plots with either purslane or grass will be established and divided in rotational paddocks. Hens will be periodically moved through the paddocks and provided with additional conventional feed to account for 80% of needed calories. After 45 days, hen weight, egg production, and egg fatty acid profile will be analyzed. 6. Determine the economic feasibility of the proposed production system. An economic analysis will be conducted and a business plan will be developed to assess the potential profitability of the purslane-laying hen system.
    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.