What does “Grass Fed” and “Grain Fed” mean?

posted on

September 6, 2023


  • Grass Fed means that the animal has been fed only grass and mother’s milk from birth to death.  Most Grass Fed cattle are slaughtered at about 2.5 years of age. 
  • Grain Fed means the calf gets born and lives on mother’s milk and grass until it is about 6 months old.  Then it goes to a feedlot in a factory farm and gets fed grains as the major parts of its diet until it is slaughtered at about 1.5 years of age.  

Grain feeding makes the animal grow much faster and get much fatter than Grass feeding. 

There are a lot of questions about Grass Fed vs Grain Fed beef.  Things like: Is grass fed actually better for you than grain fed?  What tastes better, grass or grain fed?  

By the end of this article you will have more information and be much more able to make up your own mind. 

I will give you my opinions on the above questions and then try to give the reasons I came to those conclusions.  I will try and be as fair as possible. 

  • First, the easy question:  Does grass fed taste better than grain fed?  I think so, but there are a lot of people who do not like it because it tastes different.  One thing is for certain, grass fed is not going to taste the same as the hamburger you get at any fast food restaurant.  Most people say that grass fed beef has more flavor than grain fed but in the end, flavor comes down to personal preference. 
  • Is grass fed better for you than grain fed?  I think it is, but maybe not for the reasons you might think. 

Grass fed beef is leaner than grain fed beef. It has become widely thought that lean meats are  better for you than fatty.

It depends whether you need or want fatty or lean beef. It is possible to finish a grass fed animal with plenty of fat on him, but it takes pretty careful feeding and also takes more time than a grain fed animal.  It also requires a different skill set for the farmer.  Knowing when to move cattle from one pasture to another and managing the land is different from knowing when to give the cattle more grain and managing that supply chain. 

When talking about the health benefits of Grass fed beef versus grain fed, there are two main health factors that come up.   

The fats: 

Grass fed beef has a higher ratio of Omega 3 compared to Omega 6 fats than Grain fed beef.  Some studies show that 

Omega 3 fats are definitely good for you.  They may lessen the risk of many diseases and health ailments like: 

  • Cardiovascular disease (CVD) 
  • Abnormal heart rhythm (arrhythmia)
  • Blood Clots. 
  • Some forms of cancer including breast cancer. 
  • Alzheimer’s disease and dementia. 
  • Age Related Macular Degeneration. 
  • Increase HDL (good) cholesterol. 
  • Lower your blood pressure. 

Next questions are: How much Omega 3 fats are needed per day?  How much is in Grass Fed Beef? 

The National Institutes of Health says we should get 1.1-1.6 grams per day.  We will take the average and say you should get 1.4 grams per day. 

How much Omega 3 fats are in Grass Fed beef?  A quarter pound of grass fed ground beef contains about 0.055 grams of Omega 3 fats.  A little math shows that a quarter pound of grass fed beef contains about 4% of the daily need for Omega 3 fats. 

There ARE more Omega 3’s in grass fed than grain fed, so grassfed is better for you in that regard. We should take whatever we can get wherever we can get it. Grass fed beef is not a panacea for all ills but it is a step in the right direction. 

Other health benefits, antioxidants, vitamins, etc: 

An antioxidant is, in very simple terms, a molecule that has an electron it can ‘loan’ to a free radical. It is a molecule that ‘wants’ to have one of its electrons more fully used. 

A free radical is a molecule that is looking for an electron to borrow.  It ‘wants’ to find an extra electron it can more fully use. Free radicals come about naturally by the body converting food to energy, exercise, etc. Basically the body is just living day to day. 

Too many free radicals are not good for the body and cause inflammation, sore muscles, and many other symptoms. There is also data that shows that chronic inflammation can bring about cancers. 

There are studies (here, and here) with lots of technical language that show that grass fed beef compares very favorably with grain fed beef in terms of antioxidants, the vitamins A and E, as well as other health-positive substances. 

I should be sure to note here that beef does not have all the antioxidants in the universe. There are MANY different sources and kinds of antioxidants. It seems to me that there are many different types of human bodies and what works very well for one type of body will not work as well for another. People try a number of different diets that include different portions of meat.  The results are mixed.  What works for you may not work for someone else and vice versa. 

Side-by-Side Comparison: Grass Fed vs. Grain Fed

It is true that ‘we are what we eat’.  By the same token, what WE eat is what IT eats.  An animal that has a simple diet of carbohydrates is not going to have nearly the complexity or variety of compounds in its body as a pasture raised animal that gets a wide variety of forages in its diet. 

The factory farmed cow can be prone to disease and low immune system function. This is one of the reasons that antibiotics are fed to factory farmed animals. 

The pasture raised, grass fed animal will have a much cleaner environment than the factory farmed animal. 

The pasture raised animal will have much less stress than the factory farmed animal.  Stress is a big cause of chronic illness in animals as well as humans. 

Here is a table that gives a side by side comparison between grass and grain fed beef. 

Grass Fed

Grain Fed

Feed: Grass and other forages. Free choice by the animal. 

Nutrients of feed: High in lignin, active chlorophyll, vitamins, minerals 




Nutrients of product: Higher concentration of Omega 3 fats, More vitamins, minerals and antioxidants. Less fat overall but this can vary widely. 

Time from birth to slaughter: 18-30 months. 

Stress level:  Low 

Cleanliness of environment: Usually high but there can be mud and dirt. 

Environmental impact: Overall, under debate. 

Little waste pollution impact. 

Higher Methane output due to longer life span. 

Management intensive grazing has been proven to sequester carbon. 

Added Hormone Use:  Usually not. 



Antibiotics: Usually no, unless an animal gets sick.  Pasture raised animals are much less prone to disease than factory farmed animals. 

Feed: Grains, mostly corn and soy, some hay or silage. 

Nutrients of feed: High in carbohydrates, quickly digestible.  Many vitamins and minerals have evaporated or were never there in the first place. 

Nutrients of product:  More fat overall, less vitamins A, E, antioxidants. 




Time from birth to slaughter: 12-18 months. 

Stress Level: High due to crowding. 

Cleanliness of environment: Lower than a pasture. More fly pressure. 

Environmental impact: 

High waste pollution impact. 

Methane output is less than Grass Fed due to shorter life span. 

High carbon footprint due to current farming techniques used in grain farming. 

Added Hormone use: Yes, to increase growth rates. 

Antibiotics: Yes. Usually done to combat stress related disease and high carbohydrate rumen acidosis. 


What matters more: feed or lifestyle?

The lifestyle of the animal matters more than the feed.  

An animal that is in a factory farm is crowded among his neighbors and continually under stress because of this. Crowding linked with stress means that disease can go through a herd at tremendous rapidity. This is one of the reasons that antibiotics are fed to factory farmed cattle. 

The factory farmed animal’s feed is a much higher carbohydrate blend than grass and this is not what cattle have evolved to eat.  A cow has 4 stomachs because it needs space and time for the low quality foodstuffs of its normal diet to ferment. The fermentation process is what provides the animal with the sugars it needs to operate and grow.  A factory farmed animal gets its feed sort of pre-digested. The flora and fauna in the animal’s gut brings about a high acid state so the animal gets sick with rumen acidosis. Antibiotics are fed to the cattle to knock down their internal biome so there is less acid created. 

Pigs and other non-ruminants have evolved to eat a high grain diet and can much better withstand the higher carbohydrate feedstuffs. 

Factory farming uses processes that do not normally occur in nature. The animals have not evolved for those situations.  Is it any wonder why it causes trouble overall? 

So is grass fed meat better than grain-fed?

In summary: 

  • GrassFed beef is marginally more healthy as food than grain fed.  It provides a better fat profile as well as more antioxidants and vitamins.  It cannot be said that grass fed beef will supply all the Omega 3 fats, antioxidants, vitamins and minerals needed for a healthy diet for all people.  Carnivore dieters will contest that statement.   
  • As far as the health of the animals themselves goes, grass feeding is by far better.  The animal lives a very low stress and healthy life from the moment of birth to the day of slaughter. 
  • Environmentally, grass fed appears to be better than grain fed, though parts of this are still under contention.  Mono cropping to produce grains pulls carbon out of the soil whereas if that land were used as pasture under management intensive grazing, carbon would be going back into the soil and there would be far less emissions from machinery. 

More from the blog

What Does “Grass Fed” or “Organic” Mean?

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What Does “Grass Fed” or “Grass Finished” Mean?

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