“It’s always cheaper to let your cows do the harvesting,” said Laura Paine, grazing broker with Southwest Badger Resource Conservation & Development Council. In the northern U.S., pasture growth provides forages for only six months, and producing or purchasing hay is often a grazier’s largest expense. In a 2010 study, Paine and other researchers found that pasture cost $14 to $40 a ton, while producing hay costs $70 to $90 per ton, and purchased hay is $90 to $140 a ton – and prices have not gone down.
Paine explained the concept of building a “forage chain” to extend the grazing season, as well as stockpiling forages for cooler seasons, at the Midwest Organic & Sustainable Education Service Conference held earlier this year in southwest Wisconsin.
The idea is to set up a calendar for your operation and utilize not only warm-season and cool-season perennials but also consider warm-season and cool-season annuals into a grazing system. The goal is to graze cattle nearly year-round, she said.
The first step is extending the grazing season for existing cool-season pastures. Paine explained that 50 to 60 percent of pasture yield come in April to June, but stockpiling can usually feed cattle in the pasture until December and sometimes provide grazing in March or April depending on the winter.
Taking cattle off of a pasture starting in August gives the forages a chance to rest and grow until the frost. It is then “stored” in the field until needed for winter feed. “The mass and quality is maintained by the cold, dry weather,” Paine said.
Stockpiling takes advantage of the second flush of growth of cool-season grasses, but effective stockpiling requires adequate nitrogen and water. She cited research that showed without nitrogen and irrigation, yields for stockpiled forages are generally one to 1.5 tons per acre.
With nitrogen yield increases to 1.8 to 2.7 tons, and with nitrogen and irrigation yield is two to 2.5 tons. Tall fescue and orchardgrass performed the best. Legumes don’t perform as well as grasses because they tend to lose their leaves, but alfalfa and birdsfoot trefoil performed the best in the studies Paine reviewed.
Non-organic farmers have a variety of cost-effective choices for nitrogen fertilizer. Organic farmers have more limited choices. Paine said when applying organic nitrogen sources, graziers need to apply 12 to 20 tons of dairy or beef manure per acre (based on 3 to 5 pounds of nitrogen per ton, testing is recommended).
Other options include using five tons per acre of dairy compost or 3.5 tons per acre of poultry compost. Fish-based fertilizer (5-0-0) requires 1,200 pounds per acre. She advised these are slow- release nitrogen sources and results may vary.
The only organic nitrogen fertilizer organic graziers can use is Chilean Nitrate, and Paine advised the cost may not be worth the extra yield.
She said it is better to capitalize on “free” nitrogen provided by legumes in the pasture. Paine recommended planting 50 percent legumes. White clover fixes 128 pounds of atmospheric nitrogen an acre, and alfalfa produces 151. Red clover and birdsfoot trefoil also provide an adequate amount to feed grass growth.
She explained the nitrogen gets back into the ecosystem through the manure of the grazing animals. It important to set up pastures in a manner so that manure is evenly distributed rather than allowing the nutrients to be concentrated in areas where animals congregate such as by water, trees, other shade, lanes, etc.
She noted that stockpiled pasture yield can be significantly higher if the forages are allowed to set aside as early as July. But she also cautioned that the quality may decline when the tonnage goes up.
The quality of stockpiled forages in the early winter range from 11 to 19 percent protein and from 59 to 74 percent total digestible nutrients. “That’s pretty decent even for a dairy cow,” Paine said.
Quality will decrease as winter progresses. Protein decreases about 23 percent from October until December and another 24 percent from December to March. “But,” she said, “it absolutely depends on winter weather conditions.”
But she advised, “Like anything in grazing, the management makes a huge difference.”
Paine said the rule of thumb to calculate acreage needs is two acres per animal unit (an animal unit is considered 1,000 pounds of animal) for pasture and hay for 12 months. Assuming 3 percent bodyweight dry matter intake per day, a 1,200-pound cow needs about 36 pounds of dry matter or 1,080 pounds per month. At 1.2 tons per acres, a grazier needs to stockpile 45 acres for a month of grazing for a herd of 100 dairy cows.
Paine offered information on staging spring pasture growth. Stockpiled paddocks grazed in the spring green up first in the spring because they have accumulated root reserves until frost and are protected in the winter by the cover of fall growth.
Stockpiled paddocks that are grazed in the fall will green up more slowly because they have the root reserves but are left exposed over winter. Non-stockpiled paddocks go through winter with few root reserves and no top growth to protect the plants. They green up the slowest. This variation in green up can help graziers manage the flush of growth that occurs in the spring.
Stockpiled pasture can be very high-quality, increasing risk of bloat. It was noted to make sure cows have enough fiber in their diets before they go on pasture to prevent bloat and to avoid grazing for a day or two after frost. The risk is higher in pastures with high legume content.
Paine observed that some graziers renovate pastures regularly and the renovation process provides an opportunity to incorporate annuals into the grazing system. Other producers incorporate pasture into their annual crop rotation.
Annuals are a good tool for filling in the gaps when cool-season pasture growth is slow or to extend the grazing season. When using cool-season annuals to lengthen the grazing season, Paine recommended oats, barley, winter wheat, rye, triticale and annual ryegrass.
Recommended warm-season annuals include corn, sorghum, sudangrass and sorghum-sudan. Recommended cool-season broadleafs include turnips, rape and tillage radish. Cool-season legumes suggested include peas and soybeans. Grazing these annuals can extend the grazing season and reduce the cost of mechanical harvest.
Winter small grains such as winter rye, wheat and triticale are planted in September and are grazed in May and June. They average a yield of three to 3.5 tons per acre, 11 to 13 percent protein and have a relative forage value (RFV) of 85 to 90.
The spring small grains oats, barley and triticale can be planted in April and grazed in June. They yield 2.5 to three tons per acre with 12 to 13 percent protein and RFV of 100 to 120.
Oats, barley, triticale and winter wheat can also be planted in August and grazed in October. They will average one to two tons per acre, 10 to 12 percent protein and have a RVF of 110 to 150.
Ryegrasses (annual, perennial, intermediate and festuloliums) can be planted in spring or fall and are generally grazed 60 days after planting. Ryegrasses yield three to four tons an acre, have 15 to 25 percent protein and a RFV of 110 to 160.
Warm-season annual grasses including sorghum, sudangrass, sorghum-sudan and corn can be planted from May to July, grazed July to September and will yield two to nine tons per acre (higher yields with added nitrogen). Protein will vary from 9 to 14 percent, and RFV will range from 95 to 105.
The cool-season broadleafs turnip, rape and tillage radish can be planted from mid-June to Aug. 1 and grazed September to November. Yield will typically be two to three tons per acre, 16 to 25 percent protein and RFV of 150 to 250.
Peas and soybeans, both cool-season legumes, are both grazed 60 days after planting, with peas typically sown in April and soybeans from May to July. Yield varies from one to four tons per acre with 15 to 20 percent protein and RFV of 120 to 140.
Paine stressed that incorporating these different forage types into a grazing system means monitoring forage quality and adjusting the ration for optimal nutrition.
“With all of these grazing tools available, building a forage chain that extends the grazing season up to nine or 10 months is very doable. Remember, every day we can graze is a day we don’t have to feed,” Paine said. PD
Kelli Boylen is a freelance writer based in Waterville, Iowa.
PHOTO
Laura Paine explains the concept of building a “forage chain” to extend the grazing season at the Midwest Organic & Sustainable Education Service Conference held earlier this year in southwest Wisconsin. Photo courtesy of Kelli Boylen.
