The term “grass crops” covers any plant in the grass family, grown for food, for livestock feed, or both. For a livestock farmer, the feed side is what matters: grasses are the foundation of grazing, hay, and silage, and choosing the right species for your conditions is one of the more consequential decisions on the farm.
The grass family is enormous, with somewhere between 8,000 and 10,000 species across 650 to 765 genera, making it the fourth largest family of flowering plants. Grasses grow on every continent, including Antarctica, and many adapt to dry or saline conditions that defeat other plants. That adaptability is exactly why grasses underpin livestock feeding worldwide.
Why Grasses Matter So Much in Agriculture
The grass family includes all the major cereals: oats, barley, rice, maize, and wheat, along with minor grains such as millet and rye, and economically vital species like sorghum and sugar cane. But beyond the grains, it is the forage grasses that feed the world’s livestock.
Cereals were among the first plants humans domesticated. Domestication in the Fertile Crescent began roughly 10,000 years ago, marking the shift from hunting and gathering to settled agriculture. Rice was domesticated in the Neolithic, the japonica variety in southern China and the indica variety in the Himalayan region, and maize was domesticated in Mexico around 8,000 to 9,000 years ago.
Today around 4 billion hectares of land globally are covered in grasses, of which roughly 1.4 billion hectares are actively cultivated. Domesticated animals are fed on rangeland, meadow, and pasture, which is how grasslands became ground of central importance to human food production.
The Best Grass Crops for Livestock, and How to Use Them Safely
Some grasses are grown specifically as livestock feed. Three common choices illustrate that species selection is not just about yield, it is also about knowing each grass’s quirks and, in one case, a real safety issue.
Bermuda Grass
Bermuda grass is popular for good reason: dependable, not especially demanding on fertilizer, and high yielding. It is a warm-season grass that supports productive feeding through summer heat, when many cool-season grasses stall, and its yield makes it well suited to dairy operations. For farms in warm climates, it is often the backbone of the grazing system.
Fescue
Fescue is a tall, productive cool-season grass that makes good forage and withstands heavy grazing thanks to its deep roots. It works best as part of a mixed sward rather than a sole feed.
One important caution applies to older fescue varieties: many carry a fungal endophyte that produces alkaloids toxic to cattle, causing fescue toxicosis, with symptoms including reduced weight gain, poor conception, and in severe cases restricted blood flow to the extremities. Modern novel endophyte varieties retain the plant’s hardiness without the toxic alkaloids and are the right choice for new plantings.
Reed Canary Grass
Reed canary grass grows fast and thrives in wet soils where many grasses fail, which makes it valuable for marshy ground that would otherwise be unproductive. But it comes with a genuine safety concern that the traditional varieties carry, and it deserves stating plainly.
Older reed canary grass contains tryptamine alkaloids. These reduce palatability, which is why animals avoid the taller, more mature growth, but more seriously they can cause a nervous disorder known as “phalaris staggers” and, in some cases, sudden death in ruminants. The risk is highest during rapid spring growth, in regrowth after grazing or cutting, and under drought stress.
The solution is well established. Improved low-alkaloid varieties have been bred specifically to remove this problem, and when cut before the seedhead emerges they make excellent hay or haylage, either as a pure stand or as a companion in a legume mixture. If you are establishing reed canary grass, choose a modern low-alkaloid variety. If you have older high-alkaloid stands, manage grazing carefully, avoid grazing stressed or rapidly regrowing swards, and consider it best used cut and conserved rather than grazed hard.
“Grass selection is where a lot of feed problems are quietly prevented or created. The productive-looking grass is not always the safe one. Reed canary grass on wet ground and older fescue varieties both carry alkaloid risks that many farmers never connect to the animal health problems they later see. The answer is not to avoid these grasses, which are genuinely useful, but to choose the improved varieties and manage them knowingly.”
— Sue Su, Marketing Director of Silopak
Matching Grass to Your Conditions
| Grass | Season | Best For | Key Consideration |
|---|---|---|---|
| Bermuda grass | Warm season | Summer production, dairy, warm climates | Dormant in cold weather |
| Fescue | Cool season | Heavy grazing, mixed swards | Use novel endophyte varieties to avoid toxicosis |
| Reed canary grass | Cool season | Wet, marshy ground | Use low-alkaloid varieties; manage grazing to avoid phalaris staggers |
The broader principle is that no single grass is best everywhere. The right choice depends on your climate, your soil, whether the ground is wet or dry, and how you intend to use the grass, grazed, cut for hay, or ensiled. Mixing species, and including legumes for protein and nitrogen fixation, generally produces a more resilient and higher-value sward than a single grass alone.
Turning Grass Into Stored Feed
Grass grows in a flush and then slows, so the surplus of the growing season has to be conserved to cover the lean months. Whether you make hay or silage, the goal is to capture the grass at its nutritional peak, while it is leafy and before it runs to seed, and preserve that quality until it is fed.
For silage, the airtight seal is what preserves the crop. Silopak has manufactured silage film and bale net wrap since 2011 from premium virgin resin, sealing in moisture and excluding the oxygen that would otherwise spoil the fermentation. For a fuller treatment of choosing grazing species, see our guide on the best pasture for cows.
Frequently Asked Questions
Q: Is reed canary grass safe for livestock?
It depends on the variety. Older, traditional reed canary grass contains tryptamine alkaloids that reduce palatability and can cause a nervous disorder called phalaris staggers, and in some cases sudden death, in ruminants. The risk is highest during rapid spring growth, in regrowth, and under drought stress. Modern low-alkaloid varieties have been bred to remove this problem and make excellent hay or haylage when cut before the seedhead emerges. If establishing reed canary grass, choose a low-alkaloid variety; if managing older stands, avoid grazing stressed or rapidly regrowing swards.
Q: Which grass is best for cattle?
There is no single best grass, because the right choice depends on climate, soil, and use. Bermuda grass excels in warm climates and summer production. Fescue withstands heavy grazing and suits cooler regions, provided you use a novel endophyte variety to avoid toxicosis. Reed canary grass is valuable for wet ground, using low-alkaloid varieties. Most productive systems use a mix of species plus legumes rather than a single grass, which gives better resilience, a longer growing season, and higher feed value.
Q: What is fescue toxicosis?
It is a condition caused by alkaloids produced by a fungal endophyte living inside many older fescue varieties. Symptoms in cattle include reduced weight gain, poor conception rates, prolonged gestation, heat intolerance, and in severe cases restricted blood flow to the extremities that can cause loss of hoof or tail tissue. It is one of the more costly forage-related problems in regions where fescue dominates. The fix is to plant modern novel endophyte varieties, which keep the plant’s hardiness without producing the toxic alkaloids.
Q: When should grass be cut for hay or silage?
While the grass is still leafy and before it runs to seed. At that stage the balance of protein, sugar, and digestible fiber is at its best. Once a grass heads out, fiber rises and protein and digestibility fall, so late-cut grass produces bulky feed of much lower value. This timing applies whether you are making hay or silage, and no amount of careful conservation afterwards recovers the feed value lost by cutting too late.
Reviewed by Sue Su, Marketing Director of Silopak, on 15 September 2026. This guide has been revised to correct the timeline of cereal domestication and to add the alkaloid safety warnings for reed canary grass and fescue.
