Comfrey for Feedlots
Answered by: Richard Alan Miller
Question from: Ed
Posted on: April 13, 2002

Could you explain how this herb could be used as feedlot aliment if it is reported to be toxic and cause severe damage for the liver?

Could you send me more information on the process to make this feed lot aliment? And also on your proprietary technology to dry it?

Since certain strains of the leaf contain almost 35% protein, vitamin B12, and the cell-proliferant allantoin, attempts have been made to extract it for human consumption. Comfrey is, however, an important feed in some parts of the world. It is also grown as an organic compost and mulch.

It reached the top of its fame in 1974, when Celestial Seasonings used it in many of their herbal tea blends. That year they imported some comfrey from Brazil that was infested with woody nightshade. A number of people were poisoned, so Celestial Seasonings, in a vane attempt at damage control, immediately removed it from their blends.

What happened next was that Oregon State University and Washington State University conducted some studies to determine the content of oxalic acid and pyrollizidine alkaloids present, thinking this is what poisoned Celestial Seasoning’s consumers. Their studies showed that there were toxic levels in both the leaf and root.

The two studies were flawed however, as the plant sources they used were over six years old, with no previous harvests of the leaf. Further studies would eventually show that there was essential not toxic value of alkaloids in leaf that had been cut from the plant prior to 10% flowering (much like alfalfa).

Canada, then, without even studying the leaf correctly, made comfrey illegal for human consumption, just on the flawed studies from the two Universities. This severely limited the future use of Comfrey at that time.

If comfrey is not cut at this stage of growth, then the Leaf tends to become more root-like in both alkaloid content and texture. In some private studies conducted with Honda Corp. in Osaka, their feedlots were three 60-story buildings. Not being outside, the cattle were rampant with disease. When fed a 60% comfrey - 40% alfalfa pellet, however, virtually all diseases were eliminated.

Moving toward (but not answering) your drying question, let the cut Leaf come to a 50% sun-cure wilt, and then pick it up with a flail-chop to be taken to a drying facility (i.e. hop kiln, corn dryer, grain bin, etc.). Tobacco dryers and plywood kilns are other alternatives for dryers. Comfrey is easy to grow, but the key to success with this crop lies in proper dehydration and handling.

This aspect is proprietary, and can only be shared under non-disclosure, non-competitive contracts. I spent almost $10,000 and more than 2 years learning how to handle this crop. I used large vacuum [pick-up systems and hop kilns. Grain bins can be used, but must be modified. I am available as an outside consultant whenever this becomes more than questions.

I do plan to write a specific monograph for And, the only real way to get a field started is by rootstock.

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