Farney said there is some learning in both the cattle and the researchers associated with these summer grazing plants.
“The first day exposed nearly all the cows did not even try the okra, but the second day they consumed them before mungbean and safflower,” Farney said. “Another interesting comment about the summers, all grazing occurred when the sorghums were 2 feet tall to minimize prussic acid issues.”
For the sorghums, grazing occurred 35 days after planting. The sunflowers in that time frame were very small and immature (6 to 8 inches tall at the most) while the mungbean and okra had leaves that were over 7 inches in diameter.
“Preference studies become difficult to quantify as cattle do learn and modify grazing behavior especially after that first introduction to new plants,” she said.
When in drought
Farney suggests spending some time to determine the plant species with more drought tolerance.
“I would stay away from really expensive components of mixtures because there is a greater chance of crop failure with no moisture,” she said. “There is some literature that shows that a few different plant species as a cover crop have some environmental lee-way.”
For stocker cattle
Farney leans heavily on the grass component of a stocker cover crops plan.
She limits brassicas to a 1 pound per acre with maximum of 1.5 pounds of brassica seed per acre. Amounts over this can cause the brassicas to outcompete the grass species and reduce grass tonnage. For fall forages, the grass and brassica species offer enough protein to the animal.
“Younger calves have a stronger aversion to the broadleaves and brassicas than cows do and this can potentially hamper gains for a short duration until they begin to consume these plants,” Farney said
“In Kansas, from my research and measuring producers fields, we rarely get any fall growth of legumes,” she said. “This is an expensive component of the mixture and with the combination of low to no-growth and no need for additional protein to meet calf requirements, I do not include legumes in fall covers.”
Farney suggests oats and barley—both spring and winter varieties—to those looking to graze something other than native grass as they offer the earliest, quickest growth. Triticale is intermediate and wheat and rye will have the majority of their growth late winter and early spring. Turnips and radishes have a very rapid growth rate, but once a freeze happens, they don’t generate any more dry matter. Grass species continue to have some growth as the season goes on.
Managing the meat
During and through a drought, the reduced availability of forages hurts stocker producers the most.
“If forage is severely limiting, alternative methods of growing these calves need to be implemented,” Farney said.
She said Dale Blasi at the K-State Stocker unit has been doing interesting research that shows that limit feeding stocker calves can be a viable management strategy.
“These calves gain as well as contemporaries on less feed,” Farney said. “This allows us to stretch our forage and feed base.”
With the option of several high energy feedstuffs, when limit fed and balanced in the ration become an economical option to forage only, especially at elevated prices due to low supply and high demand.
“Substitution is another thing to consider with stockers,” Farney said. “We are essentially wanting to feed more of something else so they eat less grass or hay.”
Corn has commonly been identified as the culprit of reducing free-choice hay and grass consumption, according to Farney. A general rule of thumb for supplementing corn is 0.3 percent of the animal’s body weight or less will not reduce forage consumption. A level above that can reduce it. At 0.75 percent of body weight, for each pound of corn they will consume one pound less forage on a dry matter basis.
“It is still important to make sure to meet protein requirements,” Farney said.