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Milk is a staple in most kitchens, but the kind you choose matters.

With growing interest in grass-fed dairy and its associated benefits, grass-fed milk is becoming a popular choice for some.

Milk from grass-fed cows has higher levels of some key nutrients than regular cow’s milk. There are claims that it may be more environmentally friendly as well.

This article compares grass-fed and conventional cow’s milk to see how they differ in terms of nutrition, health benefits, and environmental sustainability.

According to the United States Department of Agriculture (USDA), grass-fed milk is cow’s milk derived from forage-fed cows. Forage includes: (1)

  • grass
  • legumes
  • brassica, such as cabbage, cauliflower, turnips, kale
  • browse (young shoots and twigs)
  • cereals in their vegetative or pre-grain state

During the growing season, grass-fed cattle must have access to pasture (1).

Whereas conventional cows are typically grain-fed, grass-fed cows consume grass as their main source of food and can’t be fed grains or grain byproducts. This diet can lead to a healthier animal and different milk composition compared to regular dairy products.

Research suggests that cows who eat grass produce milk and cheese with a better flavor and creaminess than grain-fed cows (2).

Although grass-fed milk is marketed as such, the U.S. Grade Standards for dairy are voluntary. This means grass-fed milk does not have an official product label.

However, the American Grassfed Association created its own standards independently (3).

The group advocates for, promotes, and supports American grass-fed and pasture-based farms and ranches, from farm to marketplace.

Summary

Grass-fed milk is cow’s milk produced from cows that have been forage-fed. There is no official product label for grass-fed milk, but organizations like the American Grassfed Association maintain independent standards.

Not always. Organic milk does not necessarily imply that the cows were fed exclusively on grass.

Organic dairy cattle feed on organically grown forage (including grass), hay, or grain feed. They have more living space and access to pasture than regular milking cows (4).

Organic dairy cattle that eat organic grain produce organic milk, but it’s not grass-fed milk.

These cows do not receive hormones or antibiotics because farmers must adhere to all USDA-mandated organic farming protocols (4).

summary

Organic milk is not necessarily grass-fed, as the cows may have been fed a diet of grain.

The calorie and fat content of each variety of milk are comparable. The amounts of carbohydrates, protein, and calcium are identical. This is also true between milks of different fat contents as well.

Grass-fed milk has more sodium and cholesterol, whereas regular milk has extra potassium.

Following is the nutrition information for a cup (240 mL) of each type of milk:

The total fat content is similar per cup for grass-fed and conventional milk. The two are distinguished by their fatty acid composition, which is the most significant difference.

Regular milk and organic milk contain comparable amounts of omega-3 fatty acids, but grass-fed milk has more (7).

Switching cattle from a grain-based diet to one that is mostly based on grass and legume forages can change their fatty acid profile significantly (7).

Specifically, diet can alter the balance of omega-6 to omega-3 fatty acids, which has health implications.

According to a range of sources, humans have evolved on a diet with an omega-6 to omega-3 ratio of around 1.

Western diets are high in omega-6s and low in omega-3s, resulting in an imbalanced ratio of about 15:1. This is partly due to the excessive consumption of highly processed foods and limited consumption of fish, along with added seed and vegetable oils in the Western diet (8).

Following are the reported omega-6 to omega-3 ratios for each type of milk from a 3-year study of 1,163 milk samples:

Other studies support the idea that grass-fed milk contains higher percentages of healthy fatty acids (9).

Summary

Milk from grass-fed and grain-fed cattle is comparable in terms of calories, total fat, protein, and calcium content. However, grass-fed milk contains more of a type of fat called omega-3s.

The higher levels of omega-3s in grass-fed milk, as well as its balanced fatty acid profile, may help prevent diet-related chronic conditions (7, 8).

Omega-3 fatty acids have potent anti-inflammatory effects. They support brain and heart health and have been shown to reduce symptoms of metabolic syndrome (10).

Metabolic syndrome is a cluster of risk factors that increase the chances of developing heart disease, diabetes, and stroke.

A high omega-6 to omega-3 ratio raises the risk of inflammation, heart disease, diabetes, and higher weight (11, 12).

According to one review, omega-3s might support the immune systems and exercise performance of athletes (10).

Athletes who consumed omega-3s improved their recovery time, reduced their chances of illness, and had superior performances in competition. Furthermore, omega-3s benefited mood (10).

When cattle are grass-fed, health-promoting phytonutrients (antioxidants with the potential to heal and protect) are found in their meat and milk.

In fact, cattle that feed on pasture have numerous phytonutrients in amounts comparable to those found in plant foods. Phytochemicals may have anti-inflammatory, anti-cancer, and heart-supporting properties (13).

Summary

The higher levels of omega-3s in grass-fed milk fight inflammation and may prevent chronic conditions like heart disease and diabetes. Research indicates that omega-3s have a beneficial impact on the immune system and exercise performance of athletes as well.

Grass-fed milk has a higher production cost — partly because grass-fed farms have to maintain far more acreage to sustain each cow.

Depending on the brand you choose, grass-fed milk may be three times more expensive than regular milk.

For example, the cost of Horizon Organic’s carton of grass-fed milk is about 68 cents per 8 ounces, compared to 20 cents for the same amount of regular milk (14, 15).

Summary

Grass-fed milk is more expensive than regular milk because of the higher cost of raising cows on a grass diet.

Consumers are increasingly looking for food options that are environmentally and ethically responsible (16).

When compared to conventionally raised cows, grass-fed cows follow a more natural diet and appear to live in better conditions. They can forage freely since they’re not restricted by limited space.

The grass-fed movement is based on a farming practice known as regenerative agriculture. It holds that grazing cattle is essential for a healthy ecosystem and that grass-fed cattle boost grass health and soil fertility — while reducing greenhouse gas emissions (17).

However, a grass-fed diet requires more grassland, which could exacerbate deforestation and biodiversity loss.

According to the Food and Agriculture Organization (FAO), deforestation emits billions of tons of carbon dioxide and other greenhouse gases into the atmosphere. Every year, hundreds of thousands of animal and plant species perish as a result (18).

Hence, the sustainability of grass-fed milk is not straightforward.

One study investigated four grass-fed and grain-fed beef production systems that California cattle ranchers used. The researchers discovered that grass-fed production systems had higher Global Warming Potentials (GWPs) than grain-fed systems — but required less water (19).

Grass-fed cattle take longer put on weight (and ultimately attain lower slaughter weights) than grain-fed cattle. Therefore, it takes longer to farm them.

Also, grass-fed cows produce more methane than grain and corn-fed cattle.

In order to keep up with current demand and production rates, 30% more cattle would be needed to convert all of the beef produced in the United States to grass-fed systems. This conversion would lead to a rise in overall methane emissions of approximately 8% (20).

Summary

While grass feeding may improve pasture health and reduce soil erosion and greenhouse gas emissions, grass-fed cows also produce more methane and use more land, which reduces biodiversity.

Grass-fed milk is derived from cows that are fed on forage. It may or may not also be organic.

Grass-fed and regular milk have a comparable calorie and fat content, with equal amounts of protein, carbs, and calcium.

The main nutrition difference is that grass-fed milk has more omega-3s than regular milk, which may help prevent diet-related chronic conditions like heart disease and diabetes.

However, grass-fed milk is more expensive and requires more land to produce, which has environmental repercussions.

Indeed, grass-fed dairy products have several animal welfare benefits. There is, however, a debate about whether it supports environmental sustainability efforts.