“You are what you eat” applies to cows, too.

What a cow eats can significantly affect the nutrient composition of its beef. This is particularly evident when it comes to fatty acid composition.

Grass-fed beef usually contains less total fat than grain-fed beef, which means that gram for gram, grass-fed beef contains fewer calories.

However, the composition of fatty acids is also different:

• Monounsaturated fat. Grass-fed beef contains much less monounsaturated fat than grain-fed beef.
• Omega-6 polyunsaturated fats. Grass- and grain-fed beef contain very similar amounts of omega-6 fatty acids.
• Omega-3s. This is where grass-fed makes a major difference, containing up to five times as much omega-3.
• Conjugated linoleic acid (CLA). Grass-fed beef contains about twice as much CLA as grain-fed beef. This fatty acid is associated with a few health benefits.

In short, there are some significant differences in the composition and amount of fat in grass- and grain-fed beef.

Both grain- and grass-fed beef are highly concentrated sources of nutrients.

Beef is loaded with vitamin B12, B3, and B6. It’s also rich in highly bioavailable iron, selenium, and zinc. In fact, meat contains almost every nutrient that you need to survive.

It also contains high quality protein and various lesser-known nutrients, such as creatine and carnosine, which are very important for your muscles and brain.

But even though the difference isn’t great, grass-fed beef generally contains higher amounts of certain nutrients.

Compared with grain-fed beef, grass-fed is much higher in the following vitamins:

• Vitamin A. Grass-fed beef contains carotenoid precursors to vitamin A, such as beta carotene.
• Vitamin E. This antioxidant sits in your cell membranes and protects them from oxidation.

Grass-fed beef also tends to be richer in other antioxidants.