Seeds in Season | October 2025

Fall Grazing Opportunities

contributed article by Justin Fruechte, Ag Product Expert

Renovo Seed, Brookings, S.D.

www.renovoseed.com 

Two of my favorite times of year are getting pairs on pasture in the spring and turning cows on cornstalks in the fall. As cattlemen, the seasons dictate our actions, and these turnouts are like mile markers of the year.

Few things bring more satisfaction than watching cows roll a corn cob in their mouth for the first time - it’s a scene that signals the changing of the seasons. Grazing stalks remains the most popular fall and winter feed strategy, but let’s look at a few other, often overlooked, opportunities that can stretch the grazing season and reduce feed costs.

Fall Pasture Management

Thanks to timely fall rains across much of the Midwest, many forage fields are seeing new flushes of growth. This is both a blessing and a challenge. While cattlemen are experts at managing cows, we sometimes forget that managing the plants those cows consume is just as important.

Fresh fall grass can test nearly as high in protein as spring pasture. Since calves are nearly knocking over their mommas while nursing, this nutritional boost is needed. The downfall to that lush grass is that it is extremely digestible, with little lignin to satisfy a rumen. So, the combination of offering rough hay or an adjacent crop residue to the lush pasture can satisfy that rumen flow.

If you planted a diverse cover crop blend - think turnips, radishes, rapeseed, and cereal grains - you’ve created what is essentially a “TMR” for your herd. These forages can test 18 to 25 percent crude protein, rivaling many high-dollar supplements. First-calf heifers or freshly weaned calves will absolutely thrive here, gaining well before winter sets in.

However, just like the lush fall growing grass, brassicas can be up to 80 percent water. Imagine eating nothing but lettuce all day - you’d feel full, but you wouldn’t get enough calories. That’s exactly what happens to cattle. To balance things out, provide access to corn stalks or unroll a bale of hay nearby. This adds fiber and dry matter, helping animals fully utilize that high-protein growth without digestive upsets.

Considerations for Warm-Season Annuals

Another fall grazing opportunity comes from warm-season annuals like forage sorghum, sorghum-sudangrass, and millets. If these were cut earlier in the summer, they often bounce back with valuable regrowth. But here’s where management is critical.

• Nitrates: Millets are notorious for nitrate accumulation, especially after drought stress. High nitrate levels can interfere with oxygen transport in the blood, essentially starving cattle of oxygen.

• Prussic Acid: Sorghums are the bigger concern here. After a frost, cell walls rupture and release cyanide compounds (prussic acid). A lethal dose can occur in minutes if animals graze too soon.

The good news? Both problems are manageable. Don’t graze until regrowth is at least 24 inches tall, and always wait 10 to 14 days after a frost before turning cattle in. Fun fact: prussic acid is a gas and naturally dissipates over time, which means patience is your best tool. For peace of mind, quick forage tests are available to measure both nitrates and prussic acid levels.

The big picture is that every extra week of grazing can save hundreds of dollars in feed costs. By matching livestock class to the right forage - heifers on high-protein covers, cows on stalks or lower-quality forages - you extend the grazing season while keeping cattle performance on track. The more carefully you manage plants in the fall, the fewer days you’ll spend hauling feed in January.

Photos courtesy Renovo Seed

learn more www.renovoseed.com 

Renovo Seed, Brookings, S.D.

The team of folks at Renovo Seed have roots that run deep in farming, agriculture, and in the overall respect for the landscape. They opened their doors in 1987 and continue to walk alongside farmers, ranchers, and landowners across thousands of acres throughout the Midwest.