It’s worth your time to listen to the old timers, says David Graham; they’ve earned their wisdom through hard experience.
Graham learned the value of old timers shortly after he came to the northeastern corner of New Mexico in 1967 as a newly minted county Extension agent.
“Everyone told me if you keep the protein level up in the cows, you’ll cut your problems associated with cattle eating locoweed way down. I’ll be darned, we’re finding out what those old guys knew is probably going to be the best answer we’ve got,” he says.
Graham, now retired from Extension work, consults and runs his own cattle operation northwest of Clayton, NM. He spent his career helping cattlemen manage and control their locoweed problems. Much of the management and control revolved around spraying pastures and deferring grazing in heavily infested pastures in the early spring and late fall.
But research at New Mexico State University’s Clayton Livestock Research Center shows that protein supplementation throughout the entire gestation period can play a major role in preventing cows from succumbing to the devastating effects of eating locoweed.
And those effects can indeed be devastating. According to Manny Encinias, New Mexico Cooperative Extension beef cattle specialist at Clayton, their research shows that heifers that were not supplemented with protein during the first trimester of pregnancy had a greater than 60% pregnancy loss from sloughed or aborted fetuses caused by consuming locoweed. However, heifers that received a commercial 32% protein cube fed at 125% of NRC requirements during the first trimester had a 100% calving rate.
Locoweed is high in protein. It’s also the first plant to turn green in the spring and the last plant to go dormant in the fall. And if cattle are protein deficient, they’ll search out plants to alleviate that situation.
“If you’re calving in March, you may not start supplementing until the first of January. Our native grasses start going dormant in late September and early October,” Encinias says.
Dormant grass in his part of the world will typically run 3½-4% crude protein, which is shy of the protein needs of a gestating cow. “If you’re not supplementing protein and the cow has a protein requirement that isn’t being met, she’s going to actively go out and find something to meet her protein needs so she can take care of herself.”
However, Encinias says, if cattle have adequate protein, they’ll generally avoid locoweed in preference to grass, even dormant grass.
Typically, ranchers throughout the Southern Plains and Southwest will start protein supplementation in the second or third trimester of pregnancy. But pregnancy in the first trimester is very fragile, Encinias says, and that’s where even small amounts of locoweed can cause problems.
But just because you get past the first three months doesn’t mean you can skimp on the range cubes. “Depending on how long cattle are exposed to locoweed, second- and third-trimester abortions are also observed,” he says.
Of the calves born to heifers that had consumed locoweed, most of them battled health problems early in life. “We treated a lot of newborn pneumonia,” Encinias says. Meanwhile, the calves born to supplemented heifers had no health problems. By the time those calves were weaned, fed in a feedyard and harvested, however, the calves from the non-supplemented heifers had caught up with their peers. There were just a lot fewer of them.
In addition to providing adequate protein throughout the gestation period, pasture management is also important. Graham suggests using a ground rig to spray pastures that have light infestations of loco weed. That creates a “loco-free zone” that you can use different ways – for early-spring and late-winter grazing, or as a safe place to put cattle that you observe eating locoweed.
“Even though we know pregnancy can be aborted, we know we can heal cattle, so to speak, if we can remove them from loco-infested pastures,” Encinias says. “They’ll get back to just about where they were (in performance) before they got in a toxic state.”
That requires intensive management, which includes observing cattle every day. But it can pay off, because once you observe the clinical signs of locoism – excitability and blind staggers – the wreck is on, Graham says.
“The first thing it affects is the reproductive system; and it takes very little. Next, it attacks the organs and immune system. The last place it goes is the nervous system.”
That’s why Graham strongly recommends creating a loco-free area. “Then if you find one eating loco, you get them out of there and take them to that loco-free area.”
Or the sale barn, he adds, because once cattle consume loco weed, he says, they can develop a taste for it. So even if they sloughed the fetus and you move them to a clean pasture, it’s possible they’ll repeat the performance the following year.
“And don’t forget the bulls,” Graham says. “I don’t know how many cows have been sold because they came up empty. But sometimes it wasn’t the cow, it was the bull. If they get on some loco, they can get sterile in a hurry.”
Once spring green-up comes around, locoweed concern diminishes until the next fall.
“If you have heavily infested pastures, it’s advisable to wait until the grass greens up,” Encinias says. “When they’re turned out on green pasture, even if there’s heavy infestation, they’ll stay on that green grass.”