As the drought continues, cattle producers are asking how to stretch their pastures. Two major techniques may be pursued, according to Iowa State University Extension and Outreach beef program specialist Denise Schwab. One is to reduce the grazing pressure from the animal side, and the other is to supplement the amount of feed available.
"Animal grazing pressure can be reduced in two ways, reducing cow numbers through selective culling and weaning calves early,” Schwab said. “Consider culling any cows with structural, health, reproductive or attitude problems. Early pregnancy checking with ultrasound may be another tool to help tighten the calving period and cull very late cycling, open cows.”
Research has shown calves can be successfully weaned as young as 90 days or less, but consistently weaned at 100-120 days of age. Some of that success depends on giving one round of vaccinations to the calves prior to weaning, and creep feeding for 10-14 days prior to weaning. Weaning reduces the nutrient requirements of the cow 30-50 percent, allowing for energy intake to go toward cow maintenance rather than milk production. Creep feeding is another tool to reduce the feed requirements on the cow, but feed efficiency of creep feeding is extremely variable. Calves tend to be more efficient after weaning when fed directly.
“The second technique is to supplement the cow while on the pasture,” she said. “There are several considerations for this, including labor and equipment to feed, controlling feed waste, and the cost of the supplemental feed.”
Feed cost really needs to be the major consideration, followed by the issue of how to deliver and control wastes. Many producers will want to feed hay as the supplement, which seems like the logical solution, Schwab said. However, if feeding hay on pasture, producers need to be extremely conscientious about control waste and limiting intake. If allowed full-time access to hay, cows can easily consume far more than is needed. Remember, you want to supplement pasture, not completely replace grazing.
Also, as hay price approaches $150-200 per ton, this probably isn’t the most cost effective option, she said.
“For example, a mature 1,350-pound cow fed completely in dry lot could consume about 38 pounds of hay per day, which would cost $2.78 per cow per day if hay is priced at $150/ton,” she said. “Studies have shown that cows need about 0.5-1.0 percent of the cow’s bodyweight in supplemental feed per day, or 7-13 pounds of hay to substitute for available forage, which would cost $0.50-$1 per cow per day. Another option is to supplement 3-5 pounds of grain or co-product and 5 pounds of hay per day which would cost between $0.65-0.75 per cow per day in addition to the available forage.”
Another possibility is to supplement only the grain/co-product while on pasture at about 5 to 6 pounds per head per day. Depending on the current pasture situation, this may or may not have enough total feed available to meet all the cows’ needs. Doubling the quantity and offering it only every other day is also a supplementation strategy that has been proven to work.
“How do you know which feeds are the most cost effective? You really need to determine the price per pound of energy or protein in the feed to compare multiple feeds,” Schwab said. “A quick way to do that is to use the Iowa Beef Center's spreadsheet 'Feed Energy Index,' which is available as a free download from the IBC website. By simply typing in the various feeds available and their costs, you can get a quick comparison of which feeds provide the lowest cost energy.”
There are multiple strategies that can help stretch pasture in drought situations such as this year. However, they should be individualized to meet the specific needs of each producer and pasture. For more help on stretching pasture, contact an ISU Extension beef program specialist.