There is no single best grass for all cows, only the best grass for a given climate and terrain.
Some popular grasses to feed cows include Bermudagrass, which is often chosen for its hardiness, Rye Grass, which is energy dense but requires good soil to grow, and Fescue, which is a good option for high altitudes or pastures with poor quality soil.
In this article, we’ll look at some of the different grasses that cows can eat and explain their benefits, learn what types of grass cows should avoid, and find out if any grass is nutritious enough to sustain a cow without any additional dietary supplements.
What Types of Grass can Cows Eat?
Cows can eat almost any grass. Cows have a complex and powerful digestive system (called a rumen) which allows them to extract energy and nutrients from hard-to-digest plant material like grass, tree bark, and other foliage.
Although cows can get by on almost anything, there are a few specific grass species that farmers have selected over the years to seed their pastures. Each species has differing energy densities and care requirements, and each is suited to different soil types and climates.
Let’s take a look at some popular species of grass and their advantages:
Bermudagrass is a warm-season grass that is packed with protein for cows. Farmers often choose bermudagrass because its roots are extremely deep (up to 24 inches) which means the grass can survive the extreme heat of the summer as well as the extreme cold of the winter without dying off.
Bermudagrass is fast-growing, and ideal for making hay to last the cows through the winter. According to the University of Georgia, Bermudagrass can create up to 7 tons of hay per acre.
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Ryegrass is energy dense compared to other grass species, so it’s desirable for grazing.
Ryegrass is the most commonly used grass for cattle grazing in Australia, due to its high energy and protein content.
Ryegrass is the grass of choice in warmer, more arid climates because ryegrass can adapt to these conditions better than other grasses.
The downside to using ryegrass for farmers is that ryegrass needs more care than other species. If ryegrass pastures are overgrazed the grass will not return the next year.
Fescue is less nutrient and energy dense than other grasses, but it has the benefit of being resistant to drought, can withstand extreme temperatures, survives animals trodding on it, and can be planted in poor quality soil.
Fescue is often planted alongside other grasses to create a more diverse and hard-wearing mix of grasses for foraging.
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Alfalfa is not a grass, but a legume. It’s one of the most popular crops for grazing animals in the US, both for foraging and for haying, because it’s more nutrient and energy dense than any grass species, and it can be cut, dried, and stored as hay for winter.
Alfalfa thrives in the warm weather, even at the height of summer when most grass species experience a drop in growth rate.
According to the University of Kentucky College of Agriculture, it’s common for farmers to let their animals graze on alfalfa, then when the alfalfa starts to thin, to overseed it with ryegrass or fescue to shore up the soil and create a more diverse pasture for their cows.
What Types of Grass Should Cows Not Eat?
Although there are some toxic cover crops including Hairy Vetch and Lupin, the biggest risk to cattle is eating too much young, fresh grass.
When a cow eats too much new grass, or fast-growing legumes like clover, it can overload cows’ digestive systems, creating froth in their rumens and lead to bloat and vomiting, a potentially fatal condition for ruminants like cows.
Farmers can mitigate this risk by rotating their cattle around multiple fields.
Read More: Can Cows Eat Clover?
Can Cows Survive on Grass Alone?
Cows can survive on only grass, because they have a unique digestive system that allows them to extract nutrients and energy from hard-to-digest foliage.
Cows have complex stomachs called rumens that break down grass by a process of multiple digestions called rumination.
Although cows could survive on nothing but grass, in many climates the grass doesn’t grow enough in winter to sustain a cattle herd, so the farmer has to supplement his cows’ diets with hay, silage, grains, or cereals.
Common supplements include hay, oats, corn, and soy.
Read More: Can Cows Eat Corn?
Can Cows Eat Lawn Clippings?
Cows can eat fresh lawn clippings, but only within 8 hours of harvesting, otherwise the grass starts to decompose and can be dangerous for cows to eat.
Once the grass starts to ferment, it should not be fed to cows, because there is a high risk of rot or mold, which can cause bloat in cattle.
If you are in any doubt, make sure to ask the farmer who owns the cows. Never feed a cow that doesn’t belong to you, since you can’t tell by looking at them which ones are sick and may be on a carefully controlled diet.
Cows can eat just about any grass. They have strong digestive systems called rumens that are specifically designed to digest grass and other foliage, extracting as much nutrition and energy as possible from hard-to-digest food sources.
Farmers usually pick the grass that best suits their environment, and there isn’t a single best grass for all cows.
Farmers need to decide whether they need a hard-wearing grass like bermudagrass, an energy-rich grass like ryegrass, or a grass that can grow in poor soil like fescue.
Farmers may also plant cover crops, grain, and legumes, some of which can be dried and used as high-energy hay to help the cows live through the winter. It’s common for farmers to plant Alfalfa for this purpose.
Stuart is the editor of Fauna Facts. He edits our writers’ work as well as contributing his own content. Stuart is passionate about sustainable farming and animal welfare and has written extensively on cows and geese for the site.