Grazing with fall annuals: Small ruminant trial plots

by Tamara Scully

The benefits of extending the grazing season don’t stop with the immediate monetary and labor-saving benefits of not having to harvest, purchase and feed stored forages to the livestock herd. There are also animal health and soil health benefits.

For those wishing to extend their small ruminant grazing season in cold weather climates, Dr. Brady Campbell, small ruminant Extension specialist with Ohio State University, has conducted recent trials on fall feeding of a variety of annuals.

During the recent 2021 Ohio Sheep Day, participants were able to view more than a dozen trial plots of annual forages and see how well the sheep grazed on these alternative forages, which had been planted in early August.

According to Campbell, “improving digestibility and availability of feedstuffs throughout the year is critical to operation success. I think that many of you will be impressed with what these forages have to offer!” (The full summary is at u.osu.edu/sheep/2021/10/05/recap-2021-ohio-sheep-day.)

In a recent OSU “Forage Focus” video presentation, Campbell and Extension Specialist Christine Gelley discussed some of the results of the alternative forage grazing trial plots.

With the opportunity to reseed their fields, and to undertake some research, 15 trial plots were planted in fields which normally are fallow in autumn and winter. These annual forages were planted for use in grazing the ewes at the Small Ruminant Center. These annuals could also be used as a cover crop if grazing is not a part of the farm operation, Campbell said, preventing soil erosion and runoff and adding organic matter to the soil.

All of the forages germinated well. Purple top turnips prefer cold temperatures and are a good choice when saving stockpiled forages for later grazing, Gelley said. They are also an ideal cover crop, can fill gaps in pasture forages and are inexpensive. The turnips were not grazed or analyzed as a bulb, only as leafy green tops.

“If we are talking about small animals, they typically will just eat the tops off and leave that root material under,” which will then regrow, and possibly be regrazed, Gelley said.

Crimson clover is very palatable and has good nutritional value. It does need to be inoculated when planted, and will fix nitrogen for the next crop. Campbell said crimson clover was one of the favored forages of the ewes.

Winifred brassica does not have a tuber, so the energy goes to the leaf material, Campbell said. It is a higher-yielding brassica. Hunter rape is a brassica similar to canola. It has little root growth, similar to Winifred. Daikon radish, with a long root, has a potent quality to it and may not be suitable to dairy sheep production due to off-flavored milk, Gelley said.

Brassica NDF (neutral detergent fiber) values are very low and can cause loose stools, Campbell cautioned. They are rarely planted alone, as digestibility can be increased by adding grasses or small grains to the pasture, which have more fiber value. Alternatively, poor quality hay can be fed in brassica paddocks, he said.

Oats can be used for grazing, cover crops or harvested for grain. Some oats winter kill, but others do not. They retain their nutritional value even after freezing, and can be “highly beneficial,” Gelley said. Proper nitrogen fertilization is needed. The forage trial plots did have rust. This fungus will reduce some of the nutritional value, but it’s not harmful when consumed in a grazing system.

Sorghum-sudangrass is very tall and can be fibrous as it matures. They utilized a thin-stalked variety so the sheep could graze the young forages. As the crop ages, the lignin increases and grazing value and consumption decreases as well. This forage will make good silage and can be a substitute for corn silage. This summer annual does come with some concerns, including prussic acid poisoning after first frost, particularly in ruminants. Nitrates can also accumulate in these plants after drought or over-fertilization, Gelley said. After frost, nitrogen issues can also occur. Do not graze these (or other warm season grasses) until about one week after a killing frost, when the animals can graze the residue safely.

Egyptian wheat, a common crop for bird hunters, is a warm-season grass and is not typically grown for livestock. It appears similar in growth to corn. It is tall-growing and will accumulate fiber as it matures, so it should be grazed young.

Austrian winter pea is typically grown in a mix. Weeds became a problem as the season progressed when grown solo in the forage trial. As a legume, it fixes nitrogen in the soil. It has a good crude protein (CP) value.

“It’s got the little tendrils, so if you are going to plant this, we’d encourage you to plant it along with some taller-growing forages so it has its ability to grow up throughout that canopy,” Campbell said of winter pea, noting that it is a tasty forage for livestock and humans alike.

Triticale, a wheat and rye cross, can be grazed, but it’s also good for wet wrapping as hay, Gelley said.

Buckwheat is enjoyed by pollinators and makes a great cover crop. It is quick to establish, and with a short growth period, maturing in less than 40 days, Campbell said.

“Unfortunately, due to the way we planted all of these forages, they were all at the same day of age in terms of growth,” Campbell said, and the buckwheat was too mature when analyzed. At a younger age, the forage value would be higher.

Soybeans were originally grown as a forage crop in the U.S., Gelley said. Grazing types of soybeans send more energy to the leaves. Grazing prior to oil development is ideal. Soybeans can also be ensiled and stored in bags, although harvesting can be difficult as they tangle in equipment. The fuzzy material on the leaf is pubescence, and animals may need some time to adjust to these leaf hairs.

“As we were looking at these ewes, soybeans were unfortunately one of the last consumed,” Campbell said. However, once that was all they had, they enjoyed it, and consumed it well, he added.

Barley is “rocket fuel,” with a 33.5% CP value, the highest of all the forages tested. It is also grown for grain. Winter rye, like barley, had lower than ideal yields, but was a high-quality forage. It’s best to plant all small grains in autumn, rather than August, for best growth and yields, Gelley said. They need to be grazed or harvested before or during early boot stage.

Sunflowers may be an “unconventional forage,” Campbell said, but the sheep enjoyed grazing them. The variety grown for the trial is good for oil production. The non-blooming flower head, as well as the leaves, were enjoyed by the ewes, and they also ate the stem down to the taproot. Bloom or pre-bloom is the optimum time to graze. It can be used as a silage crop. “We were really pleasantly surprised,” and the nutritional qualities are good, he said.

Filling those forage gaps in your grazing system by turning to some alternative annuals can benefit your livestock, soil and bottom line. For more information on small ruminant forage trials, visit u.osu.edu/sheep/2021/10/19/winter-grazing-annual-forages-improve-lamb-growth-and-health-parameters.

Leave A Comment