Callaway County
Callaway County
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Jarman's Weekly Agronomy News August 16, 2000 |
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Beware of Baling Toxic Plants along with Hay for Livestock |
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Toxic Plants in Hay Jim Jarman |
The poisonous plants that lurk in Missouri pastures, ditches and fencerows can harm and even kill livestock that eat them along with baled forage. An older University of Missouri Guidesheet, G-4970, "Plants Poisonous to Livestock," has be updated to familiarize farmers with poisonous weeds in Missouri. It lists, describes and illustrates the most common toxic weeds along with symptoms to look for in suspected cases of livestock poisoning. The more complete weed descriptions and poisoning symptoms are an important update. Farmers can more accurately identify the dangerous weeds and identify symptoms in poisoned animals. There are a number of producers who will send in a plant for identification. They're second question usually is, "Is it poisonous to livestock?" Several toxic weed species are common in native or improved Missouri pastures, but the animals tend to avoid them in the field. They often have an aroma or certain characteristics like spines or thorns that make them undesirable to livestock." Danger looms when farmers fail to scout their hayfields for toxic weeds before cutting. In cut hay, the poisonous plants might be mixed in with desirable forage and the animal might not detect it. People who are cutting hay need to pay attention to what they're seeing in the fields. Just this week a sample of pasture weeds came into the Callaway County Extension Center. Fortunately, they were cockleburs past the seedling stage of growth and easily identified. Unfortunately, the field had already been cut and baled. Now the farmer must determine if the hay is too dangerous to feed or not. The cost of a replacement animal can buy a lot of hay. The most common poisonous plants of Missouri include black cherry, black locust, black nightshade, bouncing bet - also known as soapwort - bracken fern, buttercup, common cocklebur, field horsetail, jimsonweed, johnsongrass, milkweed and mustard species, Ohio buckeye, poison hemlock, common pokeweed, snow-on-the-mountain, water hemlock, white snakeroot, wild indigo and wooly croton. Some of the toxic species, like wooly croton and mustard, are relatively harmless unless the animal ingests large amounts. Others contain more concentrated amounts of toxins. In water hemlock, for example, a walnut-sized portion of the root is sufficient to kill a cow. An animal can die from ingesting the common cocklebur in the amount of 0.75 percent of its body weight. A common question coming into the Extension Center has been on johnsongrass. The weather during the past year has been ideal for larger than usual flushes of johnsongrass. It has the possibility of poisoning by nitrate accumulation and prussic acid. Some other grasses used for forage can have toxicity problems such as corn, sorghum-Sudans, and grain sorghum. If there are question with these forages, have them tested for toxins. Several of the poisonous plants are more dangerous at certain growth stages. The seed or young seedling of the cocklebur, for instance, contains more toxins than the mature plant. Different livestock species can also be differently affected. Horses are more vulnerable to poisoning than many other kinds of livestock because they are unable to vomit. If livestock poisoning is suspected call a veterinarian immediately and remove livestock from the grazing area until all poisonous plants have been destroyed, he said. Eradicate the poisonous plants by mowing or applying the recommended herbicide. The source of information in this article is Fred Fishel, director of the MU Integrated Pest Management program (573) 884-6361 A seasonal reminder -- Corn is maturing fast. Since it is not drought stress this year, the timing of harvest may need to be checked now. Generally the corn grain should be dented and the leaves should be green. Watch the moisture content. The ideal moisture level depends somewhat on the type of silo used. Nutrients are lost in the drainage from a silo. Little seepage will occur from horizontal silos or small tower silos when dry matter levels range from 30 to 35 percent. There may be some seepage even when 35 percent dry matter silage is stored in large tower silos (30 feet x 70 feet). Water should be added to forage with over 50 percent dry matter to prevent the formation of tobacco-brown silage. Silage for bunker or pit silos will need to have slightly higher moisture content. Cut corn silage 1/2 to 3/4 inch long, no matter what the maturity and moisture level.
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