Kelp: Friend or Foe

kelp friend or foe featured image

Opinions on kelp for livestock vary about as much as they do on politics and religion. While one person says it’s a savior, others say it’s dangerous. The truth is somewhere in the middle. And as always, keep in mind that conditions vary from farm to farm, so what works great for one farm may not work as well on another farm.

Before we dive into the nutritional analysis of kelp, I need to tell you that it’s tough to find nutritional analyses of kelp. Most bags of kelp have no information on them in terms of what they contain. When I was at a conference in November, a representative from Thorvin Kelp said that’s because they have to meet a minimum level before they can claim to contain a specific nutrient, and most of them do not. When researching for this post, I searched for “livestock kelp” online, hoping to find at least a few for comparison.

Although there is plenty of kelp available to buy, Thorvin was the only one I found that had a complete nutritional analysis. Although Source claims to have “at least 60 elements and their associated micronutrient compounds,” the only ones listed in their guaranteed analysis were protein, fat, fiber, and iodine.

Since Thorvin was the only complete analysis I could find online, that’s what I’ll be using as a reference here, but keep in mind that levels in other brands of kelp may very well be much lower.

As an Amazon Associate, I earn from qualifying purchases.


Although kelp does contain dozens of nutrients, the only one that is in any decent amount is iodine. Kelp was used in a study to raise the iodine level in cows that were iodine deficient. Since the tolerable level of iodine is 100 times greater than the minimum level needed in ruminants, no one really worries about toxicity. However, if you have horses, they are very sensitive to iodine, so you should only give them the measured amount that is available in products specifically labeled for horses.

Thorvin kelp has 780 ppm iodine, whereas Source kelp has 660 ppm, and Sweetlix Meat Maker for goats has 450 ppm. Sweetlix Stocker B1600 Mineral for cattle has 35 ppm. Some cattle minerals have no iodine listed at all, which may explain why cattle ranchers love kelp so much.


Some people think that kelp is a good source of selenium, but it really isn’t. However, I think I found the source of that misinformation. That same study that showed kelp raised the level of iodine concluded that kelp was also a good source of selenium. Unfortunately, if you read the whole study (rather than just the abstract), you see that the group of cattle being fed kelp maintained their adequate selenium status while the control group’s selenium status went down. That’s a pretty flimsy reason to conclude that kelp is a good source of selenium. The kelp did NOT raise the selenium level of the cattle being fed kelp.

Thorvin kelp has 0.5 ppm selenium. Compare that to Sweetlix Meat Maker, which has 50 ppm selenium and the Sweetlix cattle mineral with 24 ppm, and you can see that kelp will do nothing to increase the selenium level of an animal that is actually deficient. Yes, the goat mineral has 100 times more selenium in it than kelp.

Further reading: Goats and selenium deficiency


I’ve also been asked if kelp has so much iron it that it can bind with copper, causing copper deficiency in goats. I did not find anything in my research to understand where this came from, but the numbers do not support this assertion.

Thorvin kelp has 622 ppm iron, whereas up until 2019 Sweetlix Meat Maker had 1.25%, which is 12,500 ppm, so the goat mineral had 20 times more iron in it than kelp, meaning there is no way the level of iron in kelp could be dangerously high. At the time of this edit in October 2019, Sweetlix no longer lists iron in the nutritional analysis of the product, but when I contacted the company they said the level is the same. 


Some also worry that there is so much sulfur in kelp that it will bind with copper, causing copper deficiency, so let’s look at the numbers. The amount of sulfur in Thorvin kelp is 2.8%. So, if you know that goats need about 0.26% sulfur in their diet (according to Nutrient Requirements of Small Ruminants), that sounds like a lot, but how much kelp are they eating? If it was 1/10 of their diet, it would be perfect, but there is no way that it is anywhere close to 10% of their diet, as they only have a few bites a day. I think of how little kelp is in the mineral feeder compared to how much hay is in the hay feeder, and it’s not even 1% of their diet.


Some people worry that the sodium content of kelp will cause their goats to reduce their intake of other minerals, which use salt as a carrier. I find it interesting that people worry about this while not usually checking the salt level of the minerals they have available free choice for their livestock. So, here are some comparisons …

  • Salt — 40% sodium
  • Thorvin kelp — 4% sodium
  • Sweetlix Meat Maker for goats — 15 to 18% salt (6 to  7.2% sodium)
    • prior to 2019 Sweetlix contained 10 to 12% salt (4 to 4.8% sodium)
  • Purina Goat Mineral (new 2019 formulation) — 27.5 – 32.5% (11 to 13% sodium)
    • Prior to 2019 Purina contained 40 to 45% salt (16 to 18% sodium)
  • Cobalt block — 98% salt (39% sodium) 

While livestock will only consume a limited amount of sodium per day, I don’t think the sodium equation is quite as rigid as some nutritionists would have us believe. Many cattle producers have been providing kelp for decades with excellent results. I started providing free-choice Fertrell kelp for my goats more than ten years ago with great results. It doesn’t affect their consumption of other minerals because kelp is simply a salty food. It’s not just salt, and it has a distinct flavor. I personally eat seaweed snacks, including kelp, so I know how it tastes.

Research has shown that goats and sheep are capable of consuming foods that contain specific nutrients in order to correct a deficiency, including this recent study, and they are able to do that based upon taste. If things taste different, they can associate that taste with the nutrient and consume it to correct deficiencies.

Other kelp rumors?

I find the kelp debate fascinating. I think it may be the result of some enthusiastic kelp lovers over-stating its merits, which leads to skeptics worrying that it could be too much of a good thing. Have you heard any other “facts” about kelp? Any other nutrients or elements that kelp is particularly high in? Have you seen any studies about kelp? Share your thoughts in the comment section below. Also, if you find the numbers are different than what I quote, please let me know! As you can see from the edits in 2019, the companies do change their formulations from time to time, and I want to keep this page up to date.

Are your goats getting the nutrients they need?

Test your knowledge of goat nutrition. Take my free quiz and find out how much you know!

We all hate spam, so I don't spam, and I don't sell email addresses. Unsubscribe at any time. Powered by ConvertKit
cows on grass

Are your goats getting the nutrients they need?

Test your knowledge of goat nutrition. Take my free quiz and find out how much you know!

We all hate spam, so I don't spam, and I don't sell email addresses. Unsubscribe at any time. Powered by ConvertKit

25 thoughts on “Kelp: Friend or Foe”

  1. This is fantastic! Thank you for your research on this subject. I do use kelp and I use Thorvin and I make sure that my goats get a dose of it everyday by making dosage balls because they don’t particularly like it. I give a tablespoon per 100 lbs and adjust up or down based on weight. I also include Fir Meadows Kop-Sel in the dosage balls every day based on weight. I offer free choice sweet lix mineral but they don’t seem to eat a substantial amount of it, and I have a redmond salt block out in their shed area which they use occasionally. I have Replamin on hand and if they start looking fish tail or rough coated or discolored hair I will dose them. I have two very light colored pygmy Nigerian wethers who are hard to gauge as far as discolored hair from copper deficiency but one is 10 years this month and the other is 6 years old. I also have a one year Alpine doe and an Oberhasli doe who is all red so I would think I would see orangy on the red doe and some reddish hair on the black parts of the Alpine. She only has black on the hind end. I rely more on hair condition and fish tail and that is why I use the Kop-Sel as an everyday plant base copper selenium supplement as I am in Florida sand land where the soils are deficient in almost everything. We feed perennial peanut hay mixed with coastal bermuda. More peanut for the girls more coastal for the wethers.

    I would love your advice if you think I am missing something here. And I thank you for putting out this newsletter. I have been on it for a good while and I learn a lot from you. !!

    • Thanks for your comment. Have you put kelp in a mineral feeder all by itself so they can have it free choice whenever they want? You are the first person I’ve heard say that their goats don’t like kelp. Most people say their goats eat so much, they can’t afford to have it available all the time, so they only refill the kelp feeder every few days or once a week. The North Ronaldsay sheep are one example of animals that eat it naturally. They live on an island in Scotland and eat an absurd amount of kelp and other seaweed that washes up on the shore.

      There is no reason to have a salt block available for goats, and there is a very good reason to remove it — goats will only eat a certain amount of salt every day, so if they are eating plain salt, that will reduce their consumption of the Sweetlix mineral, which is 10% salt. They can get all the salt they need from the Sweetlix. Please don’t be fooled by Redmond’s marketing. Yes, all salt has lots of different types of trace minerals, but in such tiny quantities that it is not of value as a mineral supplement. Once you remove the salt block, you may find that you need to use the Replamin less often, and their consumption of the Sweetlix will go up. Wethers almost never have problems with mineral deficiencies because they’re not producing anything (no sperm, babies, or milk), and they have a very low stress life.

      Copper deficiency causes loss of pigmentation in hair, so all colors become lighter. Black becomes a rusty red. A cream doe will become snow white. When a red doe becomes copper deficient, their hair fades to a tan. There is a picture of copper-deficient red doe in my copper course and here: Her whole body should be the same bright red as what you see on her face and legs.

      • I do feed Thorvin and yes they really don’t like it on its own other than the overweight wether who will eat anything without much question. That is why I do dosage balls. Of course leave it to me to have complicated goats. But my Ober sure makes some good tasting milk so it worth it. I’ll see how the Alpine does next year

        I only put the Redmond salt block in there because I am buying a American Alpine doe in milk from a 15 year breeder whose Florida goats look fantastic and he uses a large animal vet who also breeds Nigerians and she uses it. I’ve only put it in there a month ago but don’t really see them using it

        • I always say that you should never do something just because someone else does it. Their farm is different, other management aspects are different, and their goats are different. My friend four miles away never had to supplement with copper like I do because she doesn’t have well water with tons of sulfur and iron in it. If it ain’t broke, don’t fix it, and if it is broke, then figure out why and change that one aspect of your care. When I got started I was buying everything that everyone said worked so great for their goats, and I still had all kinds of problems. It wasn’t until I started reading the research and figured out exactly what my goats needed that their health and production improved. So, really the question is not how good your list of supplements look. The question is, do your goats look? You mentioned coat issues sometimes, which sound like copper. What about fertility and birthing?

  2. Thank you for the info! I see you provide kelp free choice. In your studies, have you found that is the best way to provide kelp to your goats? I give our lactating does Thorvin, but only top-dress their grain ration with it. I’ve found it rather difficult to find good info and recommendations in regard to feeding livestock kelp. Thanks again for all your work!

    • Top dressing is fine. It seems that most people provide it free choice in a mineral feeder in the same manner as they provide baking soda or other minerals. All of those things should always be separate so the goats can take as much (or as little) as they want of each one. Kelp goes much faster than minerals or baking soda. In fact, when most people first provide it, the goats gobble it up within a day. Some people say that after a couple of weeks, the goats don’t eat it as fast, which I’ve found to be true. But they still go through it pretty fast. Since the toxicity level for iodine is so high, that’s really not a concern, but most people wind up only refilling the kelp feeder at whatever frequency they can afford. If you have more than a couple of goats, definitely buy it in 50# bags, as it is much cheaper than smaller quantities.

      • I started using high country organics goat mineral. There is a lot of kelp and copper in this loose mineral. Most of my goats really like it and gobble it up. I give the new and improved sweetlix meat maker to the ones that will not eat the powdery kelp diatomaceous earth high copper loose minerals. I also copper bolus every 3 months. I had no idea it took so long for copper toxicity to take place. Now I’m wondering if I am giving too much copper.

        • No one should be giving their goats copper oxide (boluses) unless they are showing symptoms of copper deficiency. I do not recommend minerals with copper levels as high as New Country Organics unless you have been bolusing every three months — and your goal is to stop bolusing. You can learn more about copper and the symptoms of deficiency in my free online video course.

      • Found this very helpful!! We provide onyx lose minerals and I am wanting to try kelp for our hair loss (Bose and copper bonus haven’t worked. Is it okay to provide free range to kelp and minerals both?

        • Hair loss is NOT a symptom of copper or selenium deficiency, so I would not expect either of those supplements to make a difference. Hair loss is usually caused by either external parasites or zinc deficiency. The only thing that kelp has in abundance is iodine, which won’t help with hair loss either. Here is the basic info on zinc deficiency:

          And if you really want to take a deep dive, you can listen to my interview with Dr. VanSaun (or read the transcript)

          I’d also suggest checking the goat(s) for lice, which are usually around the shoulders, but you need to separate the hair and look VERY closely for about 15 seconds to see if anything is crawling through the hair. To get a diagnosis for mites, you would need a skin scraping from your vet.

  3. Great article. I get 50lbs bags of kelp for goats and garden. It is Acadian Seaplants. Harvested from cold clear waters of N. Atlantic. The product comes from Canada. This is the best option available to us although we live in California. And logic tells me I should be getting pacific kelp from a carbon footprint stand point. But all that aside this kelp is certified organic. Would you comment on that?. How can kelp not be organic.? Are there kelp farms? Also have you heard anything about Pacific kelp vs Atlantic kelp. I think they are different species. Thank you for all the helpful info.

    • I have not been able to find info about how kelp can be certified organic. From what I’ve seen, kelp is wild harvested. Everyone who sells N. Atlantic kelp talks about it being less contaminated than Pacific kelp because of the Japanese nuclear disaster a few years ago.

  4. Hi Deborah! After reading the above, it seems that kelp would not be harmful to goats, but if they are already getting a good loose mineral free choice, it makes me wonder if kelp is even all that helpful? Do they even need kelp? I have been giving our goats a little as a top dressing on their feed but recently ran out. I am not sure if I should keep buying it. Thanks!

    • If you have fertility problems and you know the goats are getting plenty of copper and selenium, additional kelp might be helpful. Kelp is mostly high in iodine, which is important for thyroid function, so a deficiency could cause fertility issues.

  5. I’ve offered organic kelp free choice to all my livestock, goats, cows, and chickens for years and they have all performed far better on kelp than the formulated livestock minerals available.
    I too have heard from goat owners concerns about iron in kelp, but though this is utterly silly. You hit on the crucial point of the matter when you said “kelp is a food”! Exactly! And you are always going to have fewer potential issues when you get your vitamins and minerals from a FOOD source instead of some laboratory concoction. I’m sorry, but an animal science degree does not make anybody smarter than mother nature! Even though they seem to think it does. Don’t be fooled, feed producers are out to make a profit and if they think loading their product with this or that substance will make it sell better, they will, even at the expense of long-term health.

  6. My husband and I did a challenge of eating entirely hand-harvested food for all of 2017. We ate mostly from our garden, where I’m still learning to balance the soil minerals. Guess what? I felt a desire to overeat IF I didn’t eat kelp. After a handful of kelp (harvested by a friend) in the soup, my overeating would go away for a few weeks. My guess is that something in the kelp helped balance the minerals in MY diet! I was inspired to brave the wild Pacific in a friend’s kayak to bring in a boatload of kelp fronds to keep me in kelp for the year. The goats and ponies here get their seaweed from a 50# bag!

  7. This article has interesting comparisons. We should be mindful when comparing nutrient contents of man made products to those that are naturally occurring in a food, or in this case, kelp. (Note: I don’t know how the brands listed are made, this is just a thought). It would be like us comparing eating a bowl of berries or eating a salad to taking a vitamin pill. The nutrients are in different forms, may be absorbed by the body differently and may have benefits when eaten from whole foods that we haven’t even discovered yet. Just a thought.

    • Whatever you want to give them is fine. It’s like giving your children spinach. It’s a highly nutritious food, but spinach is not like a children’s multivitamin, and kelp does not take the place of your goats mixed mineral that is available free choice.

  8. I feed Thorvin Kelp to my goats, horses and chickens along with cafeteria style assortment of other vitamins and minerals. My dad was a cattle rancher and feed vitamin & minerals cafeteria style starting in the 50’s until he sold the ranch in the early 70’s. He taught me that the animals know what they need but if we only feed a general multiple vitamin & mineral mix they generally can’t consume enough to correct a deficiency…so it’s basically a waste of money.

    • All mixed minerals are not created equal. It really depends on the specific brand of mineral, as well as the which mineral mix from that company. I am not a brand ambassador for any mineral companies because even the ones with the best minerals also sell some that are a waste of money. The location of the farm and what it has in terms of minerals and antagonists also comes into play, but in many cases, a GOOD mineral can work. They key word there is “good,” because unfortunately a lot of so-called “minerals” don’t really have a lot minerals in them beyond salt. Sadly, I have not actually seen a mineral block for sheep or goats that was not a waste of money because they contain so little minerals. And everything I’ve ever seen that was labeled “all stock” is a waste of money. Here is more info on goat minerals specifically:

  9. Hi!
    I live in the northeast near the shore. If I were to talk to a kelp farmer to get some of his not-quite-market-worthy kelp, how much should I get? What should I do to prep it for our goats and chickens? Lay it out to dry? Hang it up to dry?

    • Hi Emily!
      I would get all that info from the kelp farmer. He should be able to guide you on proper processing and what the actual yield is after it has been dried.


Leave a Comment

Join me online