Toxic plants negatively impact livestock by decreasing reproductive performance (breeding and calving rate), reducing weight gains, and causing animal health issues and death. Assessing and treating animals experiencing toxicity may increase operation costs through either veterinary intervention or death loss.
With prolonged drought conditions throughout many areas of South Dakota, there is an increase of invasive weeds and poisonous plants on rangelands. Identification of poisonous plants is crucial to ensure livestock production is not compromised.
Several woody plant species that are poisonous to livestock are found throughout South Dakota rangelands, including ponderosa pine, chokecherry, greasewood and broom snakeweed.
Several species of poisonous plants are invasive and can easily establish dense stands when there is a disturbance on rangelands. Hemlocks, halogeton and buffalo bur can all be found throughout South Dakota and are toxic to livestock.
Locoweed and crazyweed are found throughout South Dakota rangelands, and both can cause livestock poisoning.The names locoweed and crazyweed are often used interchangeably. However, there are notable differences between the species.
Larkspurs are the second leading cause for all livestock deaths from toxic plant poisoning. Poisonvetches are considered accumulator plants that uptake excessive levels of selenium and cause toxicity problems in cattle.