A review of the most economically important poisonous plants to the livestock industry on temperate grasslands of China

Abstract

The majority of the literature on poisonous plant species in China is published in Chinese and not available to the majority of interested researchers and grassland managers in other countries. Therefore, a review of the Chinese literature was conducted to summarize the occurrence of poisonous plant species on temperate grasslands in China. We reviewed the literature to obtain general information on poisonous species but focus on locoweeds (Astragalus and Oxytropis spp.), drunken horse grass [Achnatherum inebrians (Hance) Keng ex Tzvelev] and langdu (Stellera chamaejasme L.) for information on their toxins, distribution and ecology, control methods and alternate uses. Of the almost 1300 poisonous species found on grasslands in China, these species are responsible for an estimated 80% of all livestock losses. This includes loss of performance as well as mortality. The locoweeds are a complex made up of Oxytropis and Astragalus species. The toxic principle in this complex, as well as in drunken horse grass, is the result of an endophyte fungus whereas in langdu it is produced by the plant. All these species are native to the grasslands, which suggest they have been a problem ever since herding began. Over that period of at least several millennia, herders would have learned and adapted to the presence of poisonous species. Strategies were developed and therapies employed to allow the animals to cope before and after poisoning. Nevertheless, grazing management could still be refined that would allow the use of the toxic legumes, while preventing poisonous symptoms, as has been tested elsewhere.