Dear Mark: Grass-Fed vs Grain-Finished, Lamb Feedlots, and What About Grass-Fed Eggs?

Grass Fed finalFor today’s edition of Dear Mark, I’m answering a few questions about grass-feeding several of you raised in last week’s comment section. First, is there a difference between grass-fed and grass-finished?What is the difference between grass-fed and grass-finished? Next, is it true that lamb is by definition grass-fed? Are there actually lamb feedlots, or can we be certain that the lamb we eat lived a fairly decent, grassy life? And finally, what about grass-fed eggs? Does such a thing even exist? After all, when most of us think about happy egg producers, i.e. fowl, are they munching away on their fair share of freshly sprouted greens?

Let’s find out:

Is there a difference between Grass-Fed and Grass-Fed/Grass-Finished?

Until recently, “grass-fed” meant that the meat was USDA-certified 100% grass-fed and finished. But in January, the USDA stopped verifying that meat advertised as grass-fed is actually grass-fed, instead urging producers to come up with their own standards. Until that happens, producers can slap the label on however they like. And sure, most cows do spend the first part of their lives on pasture before moving to the grain feedlot, but the label simply doesn’t tell us anything definitively anymore. Legally. I imagine that most beef with the grass-fed label is indeed grass-fed, at least primarily. But there’s a lot of wiggle room.

If you’re at all in doubt, dig down deep. That’s the beauty of having a smartphone in your pocket when you shop. You can look at the package, get the name of the farm (or ask the butcher or manager for the name), google it, and discover how the farm feeds their animals or get contact info so you can inquire yourself.

Grass-fed means just that: the cow ate some grass during its life. It may have eaten nothing but grass. It may have eaten a little grass and the rest grain. It may have eaten mostly grass and then spent a few weeks or months on grain to fatten up. Most cows are technically “grass-fed,” because most cows start out on pasture before moving to the feedlot.

Grass-finished means the animal ate only grass and other stuff throughout its life: hay, silage (kind of a fermented grass), forbs (herbaceous flowering plants that are not grasses), vegetative grains (grains that look more like grasses, before they become the grains we know), browse (random vegetation that’s neither forb nor grass), and crop residue (one of my favorite beef ranchers gave his cows leftovers from the vegetables he grew).

Grain-finished means the animal was moved onto grains after. It can last for the better part of a year or for just a few weeks. The longer a ruminant spends on grain, the more grass-based benefits are abolished from the meat. You don’t go from grain to grass, typically. Maybe there’s some weirdo out there starting his calves on corn and moving them onto grass for finishing, but I highly doubt it.

Isn’t lamb, by definition, grass-fed? That was my understanding and I’ve never heard anything about sheep feedlots. If you like lamb, it makes it easier to get grass fed meat on your regular grocery store run. Not quite the same as beef, but you can do a lot of tasty meals with lamb even with picky eaters.

That’s a common misconception. I wish it weren’t. I wish lamb were raised exclusively on grass and wild forage. They’re suited for it. They thrive on it. And yes, a large portion of lamb are grass-fed for their entire lives, and lamb is more likely to be grass-fed than beef, but not all of them. It ultimately depends where you get your lamb.

New Zealand lamb: 100% grass-fed. If a drought occurs, they may have to provide hay, but even that is just dried grass so it qualifies.

Australian lamb: The marketing page for Aussie lamb says the country’s animals “graze on natural Australian grasslands throughout their lives” and are only supplemented with grain “if a regional drought occurs.” And it appears to be true, for the most part. But according to the department of agriculture in Victoria, Australia, intensive feedlot feeding of lamb is “steadily increasing” to meet the growing demand for “lambs that meet market specifications.” There are definitely lamb feedlots, as the Australian article discusses the benefits and drawbacks of different types of lamb feedlots.

Icelandic lamb: 100% grass-fed, from what I could gather.

American lamb: Except for those “marketed directly from the pasture,” most American lamb is finished with grain. Feedlots absolutely exist. In my experience, smaller producers of lamb, the guys you’ll see hawking their wares at the farmer’s markets, produce exclusively grass-fed lamb. Just ask to be sure.


What about eggs?

Eggs are a little different. Chickens may nibble on grass. They’ll peck at it. They’ll enjoy the occasional lawn salad, absolutely. But they are omnivores through and through. They need denser sources of protein. So “grass-fed” is a misnomer.

Free-range is like “grass-fed”; it doesn’t mean much. A free-range chicken might get a little patio bereft of plant and wildlife outside the hen house to scratch around in. But it’s eating the same stuff the battery-raised chickens eat: corn and soy.

With access to grasses, weeds, and all the delicious invertebrates that populate such an environment, pasture-raised chickens produce the very best eggs.  They’re eating worms, crickets, ticks, spiders, rolypolies, larvae, ants. If it’s got an exoskeleton, they’re eating it. They may even eat a few vertebrates, like lizards, if they cross paths. This changes the nutrient composition of the eggs. Research shows that pasture-raised eggs are higher in vitamin E, omega-3s, beta-carotene, and vitamin A.

These are meaningful differences. When people were randomized to eat either pasture-raised eggs or conventional eggs, those who ate pastured eggs had blood lipids that were more resistant to oxidative damage. People eating the conventional omega-6 heavy eggs had 40% more oxidized LDL.

Regular old eggs are still a pretty good food. Most of the studies showing the relative innocuousness and even benefit of eating daily eggs aren’t using pastured eggs. They’re using the standard stuff you get at the standard grocery store. Still: just imagine the results if a large study used only pasture-raised eggs from bug-eating, grass-chewing chickens!

The best eggs I’ve ever had came from the Big Island of Hawaii. I bought them off a little old lady posted up in the Captain Cook area with an umbrella, a lawn chair, and a cooler full of eggs from her backyard chickens. A brief chat revealed they ate fallen mangos, avocados, mac nuts, and whatever bugs they could dig up in her backyard. The yolks were enormous and sunset-orange (usually, bigger yolks are more diluted and less rich), the whites were tough and cohesive (took forever for them to slip through my fingers when separating yolks; I bet they’d have made a great meringue). Even store-bought Big Island eggs costing $4 a dozen were better than most mainland pastured eggs going for $8 a dozen. So if you’re ever in the tropics, eat the eggs!

I hope that clears up some of your questions about grass-fed animal products.

Thanks for reading, everyone. Take care!

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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43 thoughts on “Dear Mark: Grass-Fed vs Grain-Finished, Lamb Feedlots, and What About Grass-Fed Eggs?”

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  1. The most appalling thing I recently learned is that farmers can LABEL their meat as “grass-fed” and actually be feeding them CORN…corn is a grass, botanically-speaking. It is a member of the grass family, as is wheat.

    This made my jaw drop–now I don’t know WHAT meat is safe to eat any more! I guess I may have to go vegetarian just to avoid grains and grass-grains. Oh how I wish I lived in or near a country that actually uses GRASS to feed their animals, and not some back-door marketing ploy.

    1. Some people actually prefer corn-fed beef. I don’t know that any of them have gotten sick or dropped dead because it’s “unsafe.” Nutritionally inferior, possibly, but unsafe? Highly doubtful.

      1. Safe, probably. I agree with you there, but if I’m paying grass-fed beef prices, I expect just that.

      2. It’s unsafe in the sense that a corn fed cow has a more acidic stomach, which can nurture the most dangerous strains of e.coli. However, proving that the infection that killed you was related to the feeding habits of the cow would be difficult…

      3. That preference has been suggested to be merely based on habit and what people are used to eating. Grass-fed beef consumers believe that grass-fed beef tastes better. And the acute, immediate safety issue seems to relate to higher e coli incidence as mentioned in another comment as well as higher risk of other antibiotic resistant bacterial strains.

    2. No need to let perfect be the enemy of good. If anything, local producers who sell their meat directly to consumers will be up-front about their animals’ feed.

  2. I get a kick out of the phrase “pasture raised eggs”, or “pastured eggs”. I know it is just (perfectly fine) shorthand for “eggs from pasture raised chickens”, but it always brings to mind whimsical image of little baby eggs frolicking around in the grass in some farmer’s field!

    1. I was thinking the same thing! The term “grass-fed eggs” made me chuckle… How do they get the grass through the shell?

      1. I like to imagine the frolicking little grass-fed eggs out playing with the grass-fed butter as well! 🙂

  3. I went on silage harvest with a custom crew two different years. Every thing we cut and took to the farmstead to make into silage was corn. Everything. That was in Kansas, Missouri, Nebraska, South Dakota, and North Dakota.

    1. Silage is way better feed than some feedlot corn. It includes all the grassy parts of the corn rather than just the seeds, and it’s fermented. The fermentation actually broadens the nutritional profile somewhat, and drops the phytates and lectins, and even breaks down some pesticides.

      1. Fantastic point. And silage can be made out of pretty much any crop, including the same grasses & legumes used for making hay. Some farmers call this haylage, but some refer to it as silage. Either way it’s excellent feed.

  4. re: They may even eat a few vertebrates, like lizards…

    Ours catch and eat juvenile mice when they can. Chickens don’t realize they aren’t still dinosaurs.

    On the “pastured” marketing misdirection, if you can’t visit the farm and check, there’s really no way to know with today’s worthless (or absent) legal definitions.

    The biggest problem with CAFO meat and dairy may well turn out to be the stealth Omega 6, especially the linoleic acid (LA). Even for someone avoiding the industrial seed oils, it’s easy to get enough second hand ?6 to prevent getting your ?6:?3 ratio down where it needs to be (near 1:1). Consequences of excess LA are cardiovascular, general inflammatory, and it may be obesogenic for those not minding their net carbs.

    The second hand antibiotics, growth hormones, pesticides and specific GMO issues may be of lesser importance.

    1. The way I look at it at least those Omega 6 fats are manufactured by the animal. Thats got to be way better than high heat solvent extraction. If I pay attention to everything else I can balance with supplementation and using coconut, olive, avocado, palm,etc for cooking all my veggies in. I hope that works because that is basically how I do it.

      1. re: …at least those Omega 6 fats are manufactured by the animal.

        a. That probably doesn’t matter.
        b. I’m not sure it’s true, but see a:

        If the ?6 18:2 LA is higher in CAFO critters, it’s higher, and the source is not really material. LA is LA.

        I personally suspect that it’s coming in with the feed and just being packed away as-is. I’m willing to be mistaken.

        If you can’t find credible organic pastured, “lean” CAFO may be safer than full-fat CAFO.

        1. The processing makes a difference, at least with me. If I mess up and consume very much soybean oil (or other industrially processed oil) my digestion complains. It doesn’t with the fat that comes attached to the meat whether it’s conventional or grass fed organic, and I buy both. I do make an effort to maintain some sort of balance though.

    2. Keep in mind oxidized omega 6 is the problem. It is true we need to balance our omega 3 omega 6 ratios but eating a handful of almonds or an avocado (both of which are loaded with LA) is a far cry from eating something cooked in vegetable/seed oil. Actually I saw a report showing despite high omega 6 content avocados are actually anti-inflammatory. Now I have no idea how this plays into grain fed cow, but I doubt eating a grain fed steak is equivalent to eating something cooked in corn oil. Even oxidized omega 3s will cause an inflammatory remark, most fish oils in stress the days are not good at all. Find one enriched with vitamin E (prevents oxidation) and is also packaged in a dark bottle.

  5. Anybody know if Canadian and/or Mexican beef is finished in feed lots?

      1. Canadian lamb can be grass only, but it will say so and it will be hideously expensive.

  6. A couple of things about eggs:

    First, when we lived on the Big Island in the early 1990’s those store bought eggs were shipped in from the mainland, they were NOT local eggs. So they cost a lot, they were old and “factory” produced. Maybe that’s changed??? (I hope so).

    Second, we now live in a Northern California county that has historically been a big egg producing county. So we try to go see the farms where our local “pasture raised” eggs come from. And yes, some do let their chickens roam around land with specially trained guard dogs to watch over them. So it is a little bit like what John is picturing ;o) Most of these farms do give the hens a little bit of grain feed to entice them to come into the coops at nighttime, but it’s a very small percentage of their diet and we always try to make sure that it’s organic and free of soy.

    Third, beware of eggs in cartons that proudly proclaim that the laying hens were fed a “vegetarian diet”. It’s code for grain. Chickens, as pointed out, are NOT vegetarians, and if allowed to forage for their own food they DO eat bugs.

    Finally, In places like Minnesota where snow lays on the ground for months, they obviously can’t be “pasturing” their chickens. So what are they getting fed in those places? I think anyone paying extra for “pastured eggs” has to be asking those question. It may not be realistic in winter months to get “pastured eggs” in some places.

    1. Sometimes chickens are fed flax seed. This at least is a source of omega three and somewhat better than factory farm grains. Also chickens will eat shrimp heads, fish guts, and just about anything unappetizing or past the expiration date.

  7. I’m afraid there are several misstatements in your summary of the meaning of grassfed. It’s a confusing issue, and the USDA’s recent action on their grassfed standards has made it more so. But here’s how it works:

    USDA’s Food Safety and Inspection Service did not drop their approval process for label claims. FSIS has to approve any label that appears on a package of meat. In the case of grassfed, they will approve a label reading “grassfed” or “100% grassfed” ONLY if the producer states that the animal was fed nothing but grass/forage from weaning to slaughter. If the animals in question were fed grain, the producer must tell them how much, and then the label will carry that percentage, for example, “50% grassfed, 50% grain.” This is done by producer affidavit — there is no inspection process, and that’s ALWAYS been the case with label approvals. Grass finished has no legal meaning and can mean whatever the producer wants it to mean.

    What changed in January is that the Agricultural Marketing Service, a different arm of USDA, dropped their grassfed standards, which said the animals had to be fed grass from weaning to slaughter and had to have access to pasture during the growing season. Many producers used those standards, but FSIS would still approve a grassfed label even if they weren’t met. You’ll notice that those standards did not address the use of antibiotics or hormones, the issue of feedlot confinement, or the issue of origination of the animals. Much of the legally labeled grassfed meat you see in the grocery store is imported, raised with antibiotics and hormones, and can be kept in confinement most of the year.

    There are organizations that certify grassfed producers, including American Grassfed Association, which is the oldest and only third-party certification program developed by producers with the help of animal scientists, nutritionists, veterinarians, range scientists, and others. The AGA logo on a package of meat means that the animals were fed nothing but grass/forage from weaning to slaughter, lived on pasture their entire lives and were never confined to a feedlot, were never given antibiotics or hormones, and were born and raised on US family farms. Farmers and ranchers are audited by third parties annually. You can find a list of Approved AGA Producers on the website,

    I hope that helps to clarify this immensely confusing issue.

  8. Just been to Albania a few months ago at the hotel breakfast the freshly fried eggs were all bright yellow and the majority were double yokers.

  9. The best eggs I’ve ever had were from a farmer’s market in the south of France. Bright orange yolks and such a creamy taste. The only thing I’ve had comparable here in the States are usually from friends backyards or farms that raise chickens.

    I’ve tried a lot of pastured eggs here in the SF Bay area, and the best eggs that can I’ve found are from Vital Farms. They sell a few different types (organic pastured, non-GMO conventional pastured, and conventional pastured). The middle non-GMO dozen seems to be the best value to me. About $7.50 per dozen with bright orange yolks. They also get very high ratings from Cornucopia.

    1. I tried those Vital eggs six months ago. Very expensive, as you note. I was quite disapointed. The eggs had standard caged yellow color, not orange. And they didn’t taste any different.

      I’ve had great eggs from different sources over the years, and these did not qualify.

      1. Strangely, their organic brand has yellow yolks. Try the non-gmo brand (I think they are called “Backyard Eggs.” Very deep orange in color.

        Though I’ve read from this site and Chris Kresser’s that it’s not all about orange—it’s more about the deepness of the color. Deep yellow is also good; very light or faint yellow is not.

  10. We feed our chickens EVERYTHING. Except for chicken. Bacon fat is a favorite and it’s cute when they get it stuck all over their beak.

  11. I buy my eggs from local farmers. Since I’m in PA, the chickens are given supplemental feed in the winter, but I have been assured it is non GMO. The yolks range in color from gold to deep orange and the eggs are delicious. On the rare occasion that I run out of them and buy “conventional” eggs, my daughter can taste the difference right away even if I don’t tell her.

  12. The best eggs I ever had came from my backyard. The chickens had a fence around their coop but it was moved a couple times a year. The part they weren’t using I used for my garden. Wow! 9 foot tall corn and everything grew fast and had dark green leaves.

  13. How this post (and the comments) made me wish I will be able to taste a pasture egg at least once before I die.

  14. We’re in Italy, so it’s really difficult to get pasture-raised anything – there simply isn’t the land mass, and the relative population is huge. So we do the best we can. We buy organic beef, and we keep our ear to the ground for farmers out in the hills who might keep a cow or two for their own family – they’re usually willing to part with ten kilos. Sometimes we get home-raised rabbit. Eggs come from a friend – he tosses them grain, but they’re out scavenging all day – but we haven’t yet found farmers’ chicken. We’re attending a Paleo meeting in a few weeks to discuss importing pasture raised beef from Austria – very exciting! We basically try to rotate: fish once a day, white meat once a day, red meat /organ meat / game once a day. And we hope that keeps the Omegas under control. And the budget.

  15. I’m always amazed at the level of paranoia that develops over what we eat. Sure, grass-fed animals are possibly more nutritious, but most of us have eaten conventionally-fed meat over the years, probably enjoyed it, and never gave their feed a second thought–until the grass-fed bandwagon rolled into town. On the one hand, it’s good to raise a public ruckus. If we don’t, God knows what we’ll be tricked into eating a decade or two from now. Luckily, there are always ranchers and farmers willing to comply with demand, if you can afford to pay for it, and if you can interpret all the fine print.

    On the other hand, becoming rampantly paranoid about everything we eat and wringing our hands over everything our food animals might have eaten will eventually result in a very unhealthy fear of eating anything at all. Millions of people in this world have no financial choice but to eat conventionally raised food. Should they just throw themselves and their kids under a bus because they can’t afford grass-fed meat? Of course not. Common sense tells us to do the best we can without breaking the bank or losing sleep over it. Mark understands this and often says so in his articles.

    1. +1–every time I run into the grass vs. grain or veggie vs. omnivore arguments I think about how lucky we are that we can CHOOSE how to eat.

      1. While I agree with you Shary that becoming obsessed with where food comes from can be stressful (Mark has covered this topic before, and I often fall victim to this), just because we do have the luxury to choose how to eat doesn’t mean we shouldn’t demand to know where our food comes from to help improve the system.

        Google “how much different countries spend on food” and you’ll see some great articles at the top. We spend less than any other country in the world on food per yearly income. And it’s not because we make more money that many other countries. It’s a system problem in our food system that’s been perpetuated from our desire to produce cheap calories (read: corn and soy, primarily).

        Americans have a cultural perception that food should be cheap, well, because that’s the norm here. It’s starting to change, and part of that will mean spending more money to eat healthy and build a sustainable agricultural system that benefits both us and the environment.

  16. I must admit the whole grass fed and grass finished thing gets confusing from time to time. The hamburger meat I get from my Krogers says “100% grass fed” and “certified organic”. Now it doesn’t say grass fed and finished but assuming the 100 percent remark along with the organic remark I’m assuming the cow never made it to the feedlot, assuming, perhaps I should contact the company through email and get a definitive answer. Since I’m paying 6 bucks for a single pound I better be getting premium.

  17. Know your farmer and look to see how he/she raises their animals.

  18. Dear Mark,

    Regarding confined lamb feeding, how can we stop lambs from digging a lot of holes on the ground? Which nutrient deficiency would cause that?