Grazing the dairy

Why Grass Matters

Nutritionally Enhanced Milk

Markedly higher levels of health-promoting fatty acids reported in milk from cows fed a 100% organic grass and legume-based diet.

Beneficial Beef

Recent studies evaluated organic forage fed dairy steers and the effects of growth, meat quality, and profitability.

Grass-fed Steers

Research indicates that steers fed 100% forage diet produce higher omega-3s, and was lower in monounsaturated and saturated fats.

Organic Beef

The effects of cover crop forages on omega-6 and omega-3 fatty acids, and whether or not diet adds value to the organic beef market.

Improved Nutritional Quality

Cows that consume high quality forages may provide consumers with nutritionally improved dairy products.

Contact Info

Dr. Bradley Heins, Associate Professor, Dairy Science

University of Minnesota

West Central Research and Outreach Center, Morris, MN

320-589-1711 ext. 2118

Twitter: @bradheins

Dairy Research at the WCROC


Recently, there is an increase in global demand for grass-fed and finished meat. Consumers are becoming more concerned about the origins of food, and grass-fed beef and organic beef have the potential to provide alternative beef products for consumers. Currently, organic production in the United States is dominated by cash grain crops, with the majority of organic farmers in the United States using off-farm purchases to feed their organic animal herds. However, there is a high consumer preference for “grass-fed” or forage-finished beef in the United States, which is perceived as healthier and as having less impact on the environment compared to grain-finished beef. Because of the growing trend in the organic and forage-finished beef market, cattle producers may capitalize on forage for grazing and organic cattle may represent a potential new resource for organic forage-finished beef in the United States.

Forage-Based Diets on Dairy Farms Produce Nutritionally Enhanced Milk

Consumer demand for milk and meat from grass-fed cattle is growing, driven mostly by perceived health benefits and concerns about animal welfare. In a study over 3 years, we quantified the fatty acid profile in milk from cows fed a 100% forage-based diet and compared it to profiles from milk from cows under conventional and organic management. The 100% grass- and legume-based feeding of lactating dairy cows typically yields milk fat with ratios of omega6/3 close to 1, compared to the 5.8 for milk from cows on conventionally managed farms, and 2.3 for typical organic dairy farms. The differences found in grass-fed milk may help restore a historical balance of fatty acids and potentially reduce the risk of cardiovascular and other metabolic disease.

The results of our new findings from “Enhancing the Fatty Acid Profile of Milk through Forage-Based Rations, with Nutrition Modeling of Dietary Outcomes,” is published in Food Science and Nutrition.

For more information on the research team, study methods, findings, nutrition modeling results, study costs and funding, visit 2018 Grassmilk Paper.

Link to the journal report


Beneficial Beef

Beef may be a contributing source of unhealthy fats in human diets, like some saturated fatty acids and trans fats, which are main health concerns among consumers. However, beef also contains many beneficial fatty acids, such as omega-3 (n-3) (especially docosahexaenoic [C22:6n-3], eicosapentaenoic [C20:5n-3], and α-linolenic [C18:3n-3] acids) and long-chain cis-polyunsaturated fatty acids. These beneficial fatty acids have been studied extensively in human diets and play important roles in cardiovascular, cognitive, and inflammatory functions. Forage-finished beef contains greater n-3 and polyunsaturated fatty acids, and a lower omega-6/3 ratio compared to grain-finished beef. Furthermore, all nine essential amino acids important to the human diet are in beef and a greater concentration of essential AAs are found in forage-finished beef compared to grain-finished beef. Beneficial fatty acids and amino acids in organic and forage-finished beef may influence consumer preference; however, some consumers prefer conventionally raised beef over organic and forage-finished beef due to differences in flavor and palatability sensory attributes.

At the University of Minnesota West Central Research and Outreach Center's organic dairy in Morris, MN, we have recently completed studies where we evaluated the effects of growth, meat quality, and profitability of organic forage fed dairy steers. These projects were funded by a North Central Sustainable Agriculture Research and Education (SARE) graduate student grant and the USDA-NIFA Organic Agriculture Research and Extension Initiative (OREI).


Grass-fed Steers

In the first study (Bjorklund et al. 2014), we found that the fat from the grass-fed steers fed 100% forage was higher in Omega-3 fatty acid, had a lower Omega 6/3 ratio, and was lower in monounsaturated and saturated fat, which may indicate potential health benefits of grass-fed beef. Consumers who rated the beef found no difference in overall liking for the conventional and organic beef. The organic beef had significantly higher flavor liking than the conventional beef. The grass-fed steers had the highest profit per steer ($593 vs. $442) compared to conventional steers because of lower feed costs, mainly pasture. Therefore, a low grain ration may reduce feed costs without sacrificing profit in an organic dairy system, assuming those cattle can be sold at a premium price based on their production system. The grass-fed steers required fewer resources than conventional steers.

Read findings from our 2014 study with grass-fed steers.


Organic Beef

More recently, (Phillips et al. 2017) we evaluated the grass-finished meat and whether or not it would add value to the organic beef market by improving taste and health benefits for consumers. In this study, meat from organic dairy steers finished on winter rye and winter wheat pastures was evaluated and compared for meat quality, fatty acid and amino acid profiles, and consumer acceptability.

For cover crop differences, beef from steers grazing winter wheat had higher flavor, texture, juiciness, and overall liking, and lower toughness and off-flavor compared to beef from steers grazing winter rye.

The omega-6 and omega-3 fatty acid were not different between steers that grazed winter wheat compared to winter rye. From this study, cover crops did not influence omega-6 or 3 FA concentration in the fat of beef. The omega-3 fatty acid concentration was higher in fat from Montbéliarde-sired steers compared to Holstein fat. The omega-6/3 ratio was higher in Holstein back fat compared to Normande-sired and Montbéliarde-sired steers back fat. Although these steers were finished on a forage diet, they received grain during the pre and post weaning stages. This may have influenced the higher omega-6/3 ratio in this study than steers fed a no-grain diet throughout their lifetime.

In this study, the wheat and rye cover crops were ready to graze 3 weeks earlier than other perennial pastures on the farm. This study not only applies to grazing steers, but to grazing dairy cows as well. By grazing cover crops, we were able to start grazing 3 weeks earlier in the grazing season and graze the system 3 times through with about 16 days of rest between grazing periods.

Read findings from our 2017 study with grass-finished organic dairy steers.


Improving Nutritional Quality

Improvements in the nutritional quality of beef may have the potential to improve consumer acceptability of beef and human health. The most important point for reducing inputs and increasing profits in organic dairy systems is to produce high quality forages and maximize dry matter intake on pasture. The integration of livestock in organic cropping systems is a prerequisite for long-term agricultural stability.

Shifting lactating dairy cows to rations containing substantial portions of forage-based feeds and less grain dramatically decreases the amounts of LA in milk, while also elevating levels of ALA, long-chain ω-3 FAs, and CLA. Increased reliance on grazing and forage-based diets requires careful management of soil fertility, pasture composition and forage production, and animal health. Organic dairy producers could improve the profitability of dairying by moving their herds to a 100% grass-fed pasture system versus feeding expensive organic concentrates.