Chris Penrose, OSU Extension Educator ANR, Morgan County
Many of us have harvested hay way past its prime this year, the protein and energy is low, and the fiber is high. There is a way to balance the needs of our ruminants this fall by planting some veggies.
Turnips, rape, kale, rutabagas, and swedes are all examples of some veggies from the brassica family we can plant for livestock for feed this fall with turnips being the most common.
Many studies and producer experiences reinforce that brassicas are a viable option to extend the grazing season, and reduce stored feed costs. They tend to have good protein and energy, and are low in fiber (see how this can make for good feed supplemented with poor quality hay).
Brassicas are most commonly summer seeded to extend the grazing season into early winter. Brassicas are annual crops which are highly productive and digestible and can be grazed 70-150 days after seeding, depending on the species.
Generally, crops which produce roots (the “roots” on turnips are actually soft flesh tubers with a taproot on the bottom) will out-yield those which do not produce edible roots.
Sheep are more efficient at grazing roots than cattle as sheep can chew on most of the root and leave only the bottom part of the root.
Cattle can actually pull the entire plant out of the ground when grazing if the plant is at the right stage of growth (not too mature or immature) because most cultivars have the majority of the roots above ground.
Cattle and sheep can make good use of both the tops and roots when strip grazed. This grazing method greatly reduces the waste from trampling.
Benefits of planting
One of the advantages of brassicas is that they are a high quality, high-yielding, fast-growing crop that can be planted late in the growing season. Both tops and roots can be grazed and are very nutritious.
Brassicas can be seeded in July or August for fall/winter grazing. All members of the brassica family produce forage of exceptionally high (often 85-95%) digestibility. Weight gains by stocker cattle and feeder lambs have been 0.2-0.4 lb./day for lambs and 1.5-2.0 lb./day for stocker cattle.
Top growth generally will survive temperatures between 15-20 degrees Fahrenheit, while bulbs will be about 5 degrees hardier. If temperatures fall below this level, it is best to try to graze prior to temperatures going above freezing. The plants tend to become mushy and undesirable. Planting with oats or cereal rye will allow them to survive even cooler temperatures.
The common purple top garden type turnip, as well as other cultivars, can yield over 10,000 lb./acre of dry matter. The tops average 12-20% crude protein while roots contain 8-12% protein.
Maximum quality of the plants occurs around 75 days (purple top turnips tend to mature earlier than other cultivars) and maximum quality is around 90 days as the roots mature (but the tops start to decline). At maturity, dry matter yields average around 40% in the tops and 60% in the roots.
Turnips are seeded at a rate of 2-3 lb./acre, although I have problems trying to get the seeding rate below 4 lb./acre with a drill. While brassicas have been successfully used for centuries in Europe and other parts of the world for livestock feed, the following precautions should be noted.
Brassicas can give milk an undesirable flavor. They are very high in crude protein and energy, but extremely low in fiber. Their low fiber content results in rumen action similar to when concentrates are fed; thus the need for proper roughage supplementation such as our poor quality hay.
All brassicas contain low levels of glucosinolate compounds. Again, adequate grass forage supplementation seems to prevent them from causing animal health problems.
Nitrate poisoning has been documented from excessive nitrogen fertilization plus reported instances of high accumulation of calcium and potassium that can reduce the availability of magnesium to animals. Utilize feed analyses to check and modify mineral balance of animal diets. Excessive fertilization of both nitrogen and potassium should be avoided.
No-till seeding in sod is recommended with a burndown herbicide prior to planting. They can be no-tilled (without a herbicide) into pastures at lower seeding rates so a mixture of brassicas and grass is available for grazing with the grass cover retained to protect the soil during the winter.
Although success in this method is marginal, it can be improved by a close grazing prior to seeding and delaying the fertilization until after brassica emergence.
They also can be seeded with cereal rye or oats which can protect the soil after brassicas are consumed by animals.
A 6- to 8-inch row spacing for both no-till and conventional tilled seedbeds is suggested. Seed can also be broadcasted and incorporated by cultipacking.
Brassicas should not be seeded more than 1/4-1/2 inch deep (good seed to soil contact is all that is needed). Apply 50 lb./acre of nitrogen at time of seeding or within three days.
These “veggies” offer a means for livestock producers to produce a high quality forage to extend grazing into the late fall-early winter period with only the cost of establishment, a few pounds of seed and very little fertilizer per acre. The rapid growth and yield potential makes the crop an excellent option, especially if our quality and quantity of stored feed will be an issue this year.