Use of fresh comfrey to substitute 20% of the total diet (base of corn and soy) of broiler chickens raised under a system of regenerative production

Progress report for FNC20-1216

Project Type: Farmer/Rancher
Funds awarded in 2020: $26,736.00
Projected End Date: 11/30/2023
Grant Recipient: Main Street Project Farm
Region: North Central
State: Minnesota
Project Coordinator:
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Project Information

Description of operation:

We work as a network of broiler producers under regenerative practices where all producers use a production system with fixed standards to maintain the quality of our products and the similar harmony in the activities in each of our farms, even when these are located in different states. This production system uses a specific breed of slow growing broiler chicken combined in symbiosis with species of trees, shrubs and forages for a cage-free production and creating with science and indigenous wisdom a habitat similar to the natural habitat of birds so we can reduce the stress produced by confinement preventing diseases and at the same time offering a high quality nutritional product respecting humanely all the development of our animals.


60% of the cost of production of broilers under a system of regenerative agriculture is regular feed that has a base of corn and soy. Producers' goal should be to lower this cost without affecting the health and nutrition of the chickens, thereby increasing profits.

We want to reduce the diet of regular feed by 20% with the substitution of fresh comfrey and achieve a savings of $1200 per flock in the cost of total feed. Comfrey provides a low-fiber, high-protein (22-23%), high-mineral feed—replacing more costly concentrates which contain soybeans and animal by-products for protein. Significant cash savings can be realized by the producer by feeding comfrey with minimal soy/corn-based animal feed. 

The comfrey will be sown in 10% of the total paddock area of the birds only once. The birds will obtain fresh comfrey during each of its rotations in each of two paddocks. Further, the comfrey will prevent soil erosion and control contamination because of excess minerals within the paddocks due to the manure of the birds, improving the general health of the chickens and increasing the nutritional value of the meat produced.

In 2020, after receiving the first funds for this research, we proceeded to the purchase of 3000 roots of Comfrey. These roots were planted in the final area on two of the three assigned farms. In the third farm, it was planted in a nearby area because it is still in the planning phase of the construction of the chicken coops due to the pandemic and the focus on other businesses. This farm will be replaced by another under the same standard of poultry production located in Madelia, MN; the other two mentioned above are located in the Northfield, MN area. During the year 2020 the sowing of the Comfrey roots was late and the quality of these roots was not uniform, we had germination problems of 40%. The plants that managed to germinate developed very well during 2020. Due to the pandemic (uncertain production for farms) and the poor quality of root germination, conclusive data were not collected for this investigation.

So far in 2021 one of the farms involved in this investigation did not have a production flow for the entire season (spring-autumn).

The next farm had problems finding a processor that could provide chicken processing services. Due to the pandemic all processors are operating at full capacity with low personnel to work. This has left many farms without the opportunity to process their birds.

And the third farm has decided to postpone its chicken coops construction plan and chicken production until 2022 so we have decided to use another farm within the network of producers that is already in production.

This end of summer we have requested an extension from SARE for the delivery of conclusive data for January 2023, this will allow us to reseed the already established comfrey areas and plant comfrey in the new farm that will be added to this research project.

Next steps

We already have security for the processing of all the birds under this investigation in a new processor that will be opening this fall of 2021 in Stacyville,  Iowa.

Samples will be taken from the comfrey plants and established and sent to the laboratory for a nutritional analysis and thus we will know for sure what it will be contributing to the diet of the fattening birds.

The areas to be evaluated -- where necessary -- will be reseeded and planted this autumn of 2021.

The data collection of the variants to be evaluated in this research project will begin during the 2022 season (Spring-Autumn) as described in the project plan.



Project Objectives:
  1. Reduce 20% of the total diet of regular feed (corn and soy based) by substitution with fresh comfrey in broilers raised under a system of regenerative production.
  2. Generate a significant savings of $1200.00 in the cost of feed for each production flock (1500 birds).
  3. Improve the general health of the birds, which will be evaluated through weekly physical examinations during the production period.
  4. Share results with future poultry producers of broilers using this system of regenerative production through field days, trainings, and presentations.


Click linked name(s) to expand/collapse or show everyone's info
  • Jose Callejas - Producer
  • Cliff Martin - Producer
  • Wyatt Parks - Producer


Materials and methods:

The study will be carried out in four broiler chicken production units on three different farms. Each coop has access to two paddocks of 0.75 acres each and capacity for 1500 broilers. The birds will be in a natural environment, with perennial crops (hazelnuts, elderberries) and other trees that provide shade and protection to the birds in open spaces.They will also have access to fresh grass in the pastures (perennial grass or pre-germinated grains).

Each chicken consumes on average 16 pounds of regular food in 12 weeks of life. With this project, we want to replace 20% of the total diet of regular food with fresh comfrey that is highly nutritional and edible by birds.The diet for each flock will be: 80% of commercial regular food + 20% of fresh comfrey type forage harvested by the same chickens in both pastures. Approximately 850 comfrey roots will be planted in the middle of each pasture of each production unit with the capacity to produce 5000 pounds of fresh fodder in both pastures that will be available to the chickens.

There will be four treatments. Three of them will be planted with comfrey replacing 20% of the total commercial food diet, and one treatment will be the control. The birds of the control treatment will have access to 100% of the diet based on commercial feed (basis of ground corn and soybeans plus minerals).

25% of the birds will be evaluated at random from the four treatments every two weeks after week four of chicken life until week twelve. Average weights and average consumption will be taken. A physical check will be made to determine the health of the birds. At twelve weeks the data will be compared and evaluated to assess the ability of the comfrey to maintain general health in chicken flocks under regenerative production.



Participation Summary
1 Farmers participating in research

Educational & Outreach Activities

Participation Summary:

Education/outreach description:

Outreach activities did not happen in 2020 due to delays and issues caused by Covid-19.

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.