Feeding Minerals and Supplements to a Organic Pastured Poultry Operation

Final Report for FNE11-712

Project Type: Farmer
Funds awarded in 2011: $14,007.00
Projected End Date: 12/31/2012
Region: Northeast
State: Maine
Project Leader:
Carly DelSignore
Tide Mill Organic Farm
Expand All

Project Information


“Does feeding choices such as: colloidal clay, powdered rock minerals, a mineral supplement blend, granular humates, or combinations of these minerals and humates, contribute to better grain utilization, healthier meat and less polluting manure in an organic pasture poultry farming operation?”

We ran the study over 2 years and decided to hone in comparing 2 treatments, clay and Humates fed at 1-1.5% of the diet, to a control in year 2. We did not find clear cut results but this is what we can say.

The ash test on the meat from the treatments and control was not significantly different (single samples ranging from 8-12%). The birds fed with clay and humates had a slightly more preferable flavor when a paired taste test was performed by 32 testers. The cost per bird of these additives was about $0.13 per bird. In general, we found the feed conversion was about 2.89-3.45 and the total cost of feed and supplement ranged from $6.05 to $7.55 per bird.
The soil tests indicated that the humate fed birds enriched the soil more in terms of calcium and there was less nitrate but this was not statistically significant conclusion.

We did not find a bacterial pathogen infection difference but our bacterial testing showed with repeated tests that there is significant (between 1 and 2 log reductions) of bacteria load by spraying the birds with a 2.5% apple cider vinegar concentration directly prior to bagging. This reduced bacteria content on the birds improves the quality and increases the shelf life of the bird which helps your chicken to stand out in the marketplace.

This study helped us from year 1 to year 2 decrease our feed conversion rate and we learned the cost of feeding the chickens. We think it is worthwhile to feed clay or humates and will continue to do so.


For our study, we introduced different minerals and supplements of approximately 1 - 1.5% of the total daily feed volume to the diet, alongside a controlled batch of chickens. Each are fed the same organic grain and have access to the same amount of grit and same quantity and quality of water. The supplements we used were Flora stim Clay, Azomite, Fertrell Minerals, and a combination of Azomite plus Humates and a different combination of Azomite, Humates and Clay.

The MRX clay used in this project is locally known in Mississippi as 'Baccatuna' clay. The Florastim and MRX clay is from the Strites Company which digs this out of the earth and composts it aerobically and fortifies it with the range of the most commonly needed soil or feed amendments. The product used for the SARE project was called MRX, for livestock. Its only difference from the nearly identical Strites product FloraStim, is a reduced Boron level. This clay has a high CEC (cation exchange capacity) and has measurably increased beneficial GI Tract function in all livestock. Sourced from an Amish farmer in Smyrna, Maine by Mark Fulford, 207-949-5644.

The (Menefeed) organic feed grade humates we used is mined from the Meneffee range in New Mexico. They are geologically composted humus remains layered under ancient sand stone , dating back to the dinosaur and tree fern age. It is highly effective as a feed additive in that the complex carbons will absorb toxins and reduce ammonia in the GI tract of all animals. Humates have been used since the 30's in the US, and world wide as a way to help animals convert feeds more efficiently. They are also used as an excellent soil or fertilizer conditioner to prevent leaching and chemical tie ups of reactive elements. Sourced from Lancaster Ag Products in Ronks, PA. Phone: 717-687-9222. http://www.lancasterag.com. A word of caution is to be sure to get the correct size humates; Lancaster Ag has at least two sizes and one is too large. The humates must be small enough for the chicks and chickens to eat them. The product known as (Menefeed) is the correct size. 1/32 - 1/16 “. Other companies may sell similar sizes of humates.

Azomite is a very broad spectrum semi volcanic hard rock powder originating in South West Utah. It has been mined since the late 30's, used extensively for feeding livestock as a way to supply nearly 70 elements, many of them as rare traces necessary to fulfill organ function in animals and also used in soil building. It has proven itself an effective ROI (return on investment) in livestock nutrition and soil amending. Sourced from FEDCO Growers Supply in Waterville, Maine. 207-426-9900. www.fedcoseeds.com/ogs.htm.

Fertrell Poultry Nutri-balancer, is a commercially available feed supplement for organic farmers , meant to supply most of the elements and extra proteins for livestock. the version used in this project was primarily best for poultry. Sourced from FEDCO Growers Supply in Waterville, Maine. 207-426-9900. www.fedcoseeds.com/ogs.htm.

Our Pastured Poultry Operation that we use on Tide Mill Organic Farm:

• Raised in 10 x 12 ft Salatin-style “chicken tractors”
• Moved every morning one length ahead to fresh grass
• Feeding troughs are cut 6” PVC with handles (1 per pen)
• Buckets on top gravity fill the hanging bell waterers using well water
• 60-80 birds per pen
• Harvested between 7.5 to 8.5 weeks (52 -64 days) of age.

Project Objectives:


By raising 12-15 batches of chickens for a period of 7 to 8 weeks from April - November with 400-700 chickens in each batch, and utilizing 14-18 chicken tractors we have the opportunity to develop test groups to research the effects of different minerals and supplements along with a control and repeat the data collection to validate our results.

We plan to weigh and record the grain and additional minerals and supplements for each test group, weigh and record the chickens when they go out in the field, once more before they are harvested and then the meat after they are processed. We plan to take grain samples, manure samples, forage samples and meat samples to compare the difference between the control and the chickens that are given additional minerals and supplements. We will also track mortality.

Each batch of chickens will contain 400-425 birds divided between 5 chicken tractors once they go into the field at approximately 18-21 days of age. Within the 5 tractors (1) will be the control, (2) will have Baccatuna Clay added at 1-1.5% of the total feed volume, (3) will have Azomite added at 1-1.5% of the total feed volume, (4) will have Azomite with Meneffee Humates added at 1-1.5% of the total feed volume, and (5) will have Fertrell minerals with Meneffee Humates added at 1-1.5% of the total feed volume.

The control tractor will be fed our normal 20% broiler ration and grit and the other tractor fed the same broiler ration and grit with additional minerals and supplements mixed in.

In each tractor there will be 80 birds of the same breed and the same age in the same field with the same feeders, and waterers and the same measured amount of grit and gravel. All the tractors will be numbered and the data for each tractor will be recorded separately along with the weight they are when they go out to the field, a live weight measure at 6 weeks of age and a live weight and packaged weight at slaughter. They will be labeled with separated codes and tested by the lab at the University of Maine as well as consumers who will participate in the comparison cooking and eating survey.

For the brooder stage, we will try both adding Azomite and Meneffe Humates at a 1-1.5% of the total feed volume and not adding anything to see if there is a difference in mortality and if it contributes to better field performances.

We will repeat for two or three times (depending on our budget limitations) throughout the season to validate results.


Click linked name(s) to expand/collapse or show everyone's info
  • Aaron Bell
  • Mark Fulford


Materials and methods:

We gathered materials, supplies and tools needed for our experiment. We set up our experiment.

We collected data. We brooded the chicks together feeding 2.04 lbs of grain to the birds in the brooder. We added azomite and humates to the feed of the brooder birds because our previous work supported the suggestion that they would lower mortality. Brooder mortality was 2% in SARE 1 and 3.4% in SARE 2. We manage and hope for a 10% or less mortality for the flocks of the birds we raise.

The birds were moved to the field when they were 23 days old. We divided 560 birds into 7 chicken tractors that were labeled with flagging tape. We continued collected feed weights and did a weigh check in the fields when the birds were 6 weeks old. After that weigh check we began having predator problems. On repeated occasions we discovered that birds or pieces of birds were carried off by a fox. This problem was very bad news for the integrity of our data; our feed conversion ratios and “natural” mortality were severely compromised. It took several weeks for us to catch the fox and solve our predator problems. During that time many birds, especially from the control pen were killed and wholly or partially eaten.

We began harvesting the birds at day 52 and continued through day 64, until all the birds were harvested.

We consulted with our advisor, other biology scientists and our NE SARE advisor, Carol Delaney, and our budget to plan how we could repeat the study in hopes of collecting better data. We modified our experiment and repeated the study.

In our SARE 2 study, we modified the pens by adding weighted chicken wire to the back of our pens. We also attempted to do weekly counts to check the number of chickens in each pen. Counting the 60 birds in each pen was pretty hard and time consuming. Our method was to make sure the birds were hungry and place two feeders in the pen, and take a picture, counting the heads of the birds while they were eating. It was pretty tricky and we often counted and re-counted from week to week with slight differences in numbers of birds that we couldn’t explain.

We tried to eliminate the possible effects of pasture variability and chances of predation wrecking our data by having three pens of each element we were testing for. So, we chose two amendments (based on taste test surveys and the availability and cost of the materials) HUMATES, CLAY and CONTROL. We also attached chicken wire to the backs of the chicken tractors and weighted it with boards to make it harder for predators to get to the chickens.

In SARE 2, we also controlled the amount of feed we gave the birds based on the number of the birds that were in each pen. With the first study we filled the feeders twice a day and measured the amount of feed we gave them. The problem was that in the pen that suffered the most predator pressure, the birds that were left had more space and more available grain per bird, which contributed to them appearing to have done so well. After researching and doing preliminary data gathering, we used the following feed chart to determine how much grain to feed the birds at different ages.

We entered our recorded data. We analyzed the data for feed conversion ratios and mortality.

We developed a taste test survey, found 32 willing volunteers and distributed chickens for them to compare and complete a questionnaire. We collected an analyzed their results.

We used two methods for comparing soils in the poultry study. Field observations gave us a set of plants, mostly palatable grasses and a few broad leaf species (chickweed and clovers) that both cows and poultry prefer, with the caveat that young leafy plants are best for the meat birds since mature grasses are simply too big and tough for the young birds. It is easy to see that pre grazing of the cows out front of the chicken tractors helps keep these grasses in the feed-able stage for meat birds. The plants identified are part of a field assay which compares with the soil test results to give us a better idea what nutritional value the forage actually has in it. Plants species groups are very accurate indicators of soil element availability. The soils and plant indicators outside of the chicken tractor / dairy grazing strips are significantly more deficient in all necessary elements for raising healthy livestock. It can be seem by eye even before test results were forthcoming.

We took soil samples and sent them to Lancaster Ag Products to be analyzed. More than one type of chemistry is used to extract the ratios and numbers on the Lancaster Ag test so farmers can see to some degree that there are huge differences between bio available elements in the soluble range , and far more of most elements in the reserve and less accessible form. As soil function and biology increases, more of the reserve elements enter the solubilized portion of the test results, resulting in more fertility. We also analyzed grain samples to verify the components and ingredients in our feed ration.

We did nutritional testing and chose an ash test to compare the nutrient levels once the meat was burned. It tests for the organic matter and density of minerals. We did not see a difference between the control and the birds supplemented. I think other nutritional tests need to be done to further investigate this component of the study. There was a very small sample that was analyzed because in an ash test the material is burned at 550 degrees and all the organic matter burns leaving only what didn’t burn, the non-organic material. We used that material to compare between the different birds and found no difference in the material that didn’t burn. I would recommend doing a different test to compare the nutrients in the organic material. Again, I hope we can perform different comparison tests in the future to determine if there are other differences in the nutrient content of the meat of the birds fed minerals and supplements and those who were not. The ash test will not be able to differentiate much even in the best conditions since so many factors that give the flavor to flesh and fats are burned away as part of the metabolized carbon structure of the birds. The wide customer comparison comments about quality are a better judge of this data. It is the customers that return to buy again that make the cash flow of the final product, more than measurement of mineral solids left behind.

Our manure analysis was a failure for we did not collect enough manure for the sample. It is my strong opinion there needs to be more research into this variable and we hope to compare the manure of birds fed minerals, etc. and those that have not in the near future. This may be an important set of data, since it can give the meat bird grower a little better idea of how feed efficiency is affected by inputs. For example, less ammonium in the manure may indicate better protein conversion.

We gathered materials for bacterial testing. This involved a lot of consulting and research to determine which tests to perform, obtaining sterile bags, determining the quantity of buffered peptide water need for the samples and swab analysis from the lab. We needed to make delivery arrangements so our sample would arrive intact and viable. This was really challenging for us because we live so far away from the lab. Our testing was performed in Portland by Northeast Laboratory.

Research results and discussion:

In SARE 1: The feed conversion ratios are a little messy and inconclusive. The idea was to measure the total amount of feed and divide it by the total amount meat those chickens produced. We were weighing our mortality to factor that into our total amount of meat, but after the predator attacks, were not able to weigh the chickens (or pieces of the chicken) that were carried away. Our data around feed conversion that we are sharing with you reflects that bird losses before harvest and needs to be taken into consideration. It is substantially higher than the birds tested in SARE 2.

In SARE 1, mortality results were skewed due to the predator attacks.
If the minerals contributed to a lower mortality in your flock, that would also contribute to a better feed to meat ratio.

Taste testing Results:

32 People tasted a pair of chickens. Following the same cooking instructions they compared the 2 birds for taste, aroma, texture and general acceptability. Responses indicate a slight preference for the birds fed clay or humates compared to the control. According to Mark Fulford, this also happens to be one of the anecdotal factors noted on a previous pastured chicken meat bird farm.

Bacterial Testing Results:
We determined we wanted a total viable count and a general salmonella species and a general Ecoli species test. We did a rinse test for the total viable counts and a swab test for the Ecoli and Salmonella.

Do the minerals that are added to the diet of the bird contribute to less harmful bacteria on and in its carcass?

– Need a larger sample size to make any conclusions

– Each variable (CLAY, HUMATES, CONTROL) would need multiple tests (at least 30 total: 10 per group)

Other considerations:
– Unfamiliar process; our first stab at collecting bacterial samples

– Generally a wide range of variation in the numbers of bacterial samples

We also analyzed our processing to identify the steps that would decrease the bacterial load on the birds.

After evisceration, Rinse the bird. Spray bird with organic apple cider vinegar at a 2.5% solution.

BEFORE: Colony Forming Units/g AFTER:
Total Viable Count: 37,000 Total Viable Count: 1,800

95% reduction in bacterial units

Want a log reduction…37,000 à 3,700 à 370
1 Log à 2 Logs

Repeat the test to see if you have consistent results. IF so, keep it up, the step of spraying apple cider vinegar is working with significant results.

Interestingly, in the alternative periodontal health care, biotic slide counts of several species of pathogenic bacteria are also greatly reduced and in some cases nearly eliminated by use of irrigated raw apple cider vinegar, (Braggs).

Research conclusions:

We determined the feed and additive costs per bird. It is important to know how much it is costing you to feed your birds.

Pay attention to how much you feed your birds!

-Make sure your ration is meeting your birds nutritional requirements for their breed and age.
-Feed at consistent times
-Select a feeder they can’t scratch the grain out and raise it as the bird grows.
-Don’t fill the feeders too full
-Feed along the curve (a specific amount of grain per day based on number of birds being fed and their age). See http://www.welphatchery.com/cornish_rock_care.asp
-Manage and treat (we use 1 cup of apple cider vinegar per 1 gallon of water for 3 days) for coccidiosis.

We learned a great deal about feed conversions. When comparing feed conversions, be sure to know whether the comparison refers to the live weight or dressed weight of the bird. When doing a literature review, we discovered that feed conversion ratios for Cornish Cross birds vary from 2.51 to 5.5 lbs of grain for every pound of meat. Industry reports that value based on the live weight, not dressed weight, which would affect the conversion ratio. If you were basing the feed ratio on live weight it would be lower than dressed weight. We tested the live weight to dressed weight on multiple batches of birds. In our results, the average was 76%.

We learned how much grain the birds eat throughout the different weeks of their life and how to incorporate that into chores on a working poultry farm.

We gained a tool in reducing flock mortality due to predator pressure. Weighted chicken wire was found to be very effective. We stapled it to the bottom backs of the chicken tractor leaving about 24 inches trailing on the ground behind the tractor. We used boards to weight them down so the wire was resting on the ground.

We gained a greater understanding of how mortality affects feed expenses per bird. We also were able to validate our assumptions of feed conversion rations. We were able to collect data on a certified organic, pastured poultry production system and determine the realistic costs of grain per bird. We have a helpful resource list of the different minerals and supplements we used, where to source them and how much they cost.

Participation Summary

Education & Outreach Activities and Participation Summary

Participation Summary:

Education/outreach description:

Our outreach has been very interesting, educational and given us the opportunity to network with other poultry growers. Carly presented her results with a power point presentation at MOFGA’s Farmer to Farmer Conference in Lincolnville, Maine in on November 11, 2012, NOFA New York Conference in Sarasota Springs, NY on January 27, 2013 and the Vermont Farm Show in Essex Junction, Vermont on January 30, 2013. Combined attendance of the three events was over 75 people. The events were wonderful educational opportunities with really good questions and answers and sharing of information amongst participants. A resource list and selected charts were printed and distributed. Informal talks were given at our farm during our study, the summer of 2012 as well as with our local farmer’s alliance, Sunrise County Food Alliance during the winter of 2013.

Project Outcomes

Assessment of Project Approach and Areas of Further Study:

Potential Contributions

We began this project to address the issue that grain, especially organic grain is extremely expensive component to raising chickens. When we began our proposal our grain was between .30 and.35 per pound. Last month it was .42 cents for 21% protein chick starter from MOM and .48 cents for 20% chick starter from Sawyerville. Paying attention to how much you feed your birds, feeding them at consistent times and both feeder selection and filling the feeders to the appropriate level to discourage the birds from scratching it out not spilling grain will also greatly help get you more out of your grain.

The Economics:
Dollars and cents….It is tricky to make healthy agricultural decisions based on those two sole factors. Most decisions that take into the account improving (and going beyond not damaging) the health of the environment, animal, consumers and community cannot be given a fair chance in the economic model corporations follow. We need to create a new model that works for us and being financially rewarded for taking those other factors into consideration and stewarding the land and nutrient content of the food.

Perhaps the most helpful aspect of our SARE project in terms of our farm economics was to get a very clear understanding of grain costs per bird and how mortality affects that. There was approximately a dollar’s difference in costs per bird between SARE 1 and SARE 2 because of the mortality we experienced with six week old and older birds in the pasture. Multiplied by hundreds and thousands of birds, that’s a lot of money that can be saved. We learned from the economic standpoint, reducing the mortality, especially that of birds nearing harvest date is the single most important thing you should try to do.

Before this study, we made assumptions about feed conversion rates based on educated guesses, but assumptions need to be tested for accuracy. Certified organic grain is such an expensive input and such a high percentage of the inputs of poultry production, a little difference can make a big impact. This project helped us to develop spreadsheets to manage the grain our birds eat, which has become a very valuable tool with significant economic benefits.

We also feel we learned an extra tool for our poultry processing toolbox. Our bacterial testing showed with repeated tests that there is significant (between 1 and 2 log reductions) of bacteria load by spraying the birds with a 2.5% apple cider vinegar concentration directly prior to bagging. This reduced bacteria content on the birds improves the quality and increases the shelf life of the bird which helps your chicken to stand out in the marketplace. Our taste test study suggests people slightly preferred chickens who were fed humates. Humates in livestock feed is not a new concept and has been in livestock practice for more than 40 years. It is known to absorb foul odors and flavors whether originating from poor quality grain, rancidity or bacterial decay of flesh or vegetative matter alike. Our soil tests show positive results and appear to be healthier, more biologically active soils. All of these components need to be “re-tested” to be validated, and hopefully that will happen in the near future.

Future Recommendations

We will be continuing with some independent studies with our birds that we are raising over the winter and in a greenhouse environment to see if we can get any more conclusive feed ratio data without the pasture variable. We discovered problems with groups of birds in an outdoor environment…birds mysteriously left pens and appeared in pens…if birds wound up outside of the pens, we would have to make our best guess as to where they came from. We would like to repeat the study in an indoor facility where birds could not as easily become “lost” would help protect the data.

It feels frustrating to not have clear cut results and recommendations. We can’t say based on our data we collected and analyzed to “without a doubt” add clay and humates to the diet of your chickens and you will have lower feed conversion ratio and mortality, but there is also nothing in our data to suggest that it is harmful. And there are several components that suggest it could be helpful. Minerals are an important part of a healthy system for soil, animals and humans. How do they get there? They need to be added. Pastured poultry is a unique way to add them. We are continuing to use some form of the minerals to our poultry we are raising. The minerals do not cost much per bird (.13 cents a bird or so) and they seem like an insurance policy of sorts. The potential benefits on the health of the soil, taste and customer acceptability, reduction of mortality and good feed conversion ratio of 2.89-3.45 seem worth the investment.

The idea that triggered our project continues to increase in value. We also know that the price of grain is continuing to rise, with this year’s grain prices expected to be higher than last year’s. The research SARE has funded is only becoming more and more valuable if it can provide information to help farmers better manage their poultry’s feed consumption. We feel strongly more research and data need collected furthering our initial results. We would like to work with a graduate student or poultry apprentice who can take the time to collect and analyze more data, especially around mortality, manure analysis, nutritional content and soil quality.

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.