Chapter 51 – Toxic plants

Publisher Summary This chapter discusses literature on poisonous plants that impact reproduction and embryo–fetal development in livestock species. Reproductive success is dependent on a large number of carefully orchestrated biological events that must occur in a specifically timed sequence. Locoweeds reduce reproductive performance in livestock. They affect almost every aspect of reproduction in the female. Locoweed ingestion by males is equally detrimental to male reproductive functions as it is to female reproduction. Ponderosa pine needles and snakeweeds cause abortions while lupine plants, poison-hemlock, and Nicotiana glauca cause congenital malformations. Prevention of poisoning and birth defects induced by lupines, poison-hemlock and Nicotiana spp. can be accomplished by using a combination of management techniques. Some of them are coordinating grazing times, changing time of breeding, reducing plant population through herbicide treatment, managing grazing to maximize grass coverage, and intermittent grazing. Veratrum belongs to the Liliaceae family and is a poisonous plant. Clinical signs of poisoning are most likely caused by neurotoxic cevanine alkaloids present in most species of Veratrum. Control of Veratrum is relatively easy with herbicides. Keeping sheep and other livestock species off pastures, containing them during the first trimester of pregnancy is another method. Numerous other plants containing cyanogenic glycosides have been reported to induce contracture skeletal defects in pigs and horses when ingested by pregnant dams. The recognition that poisonous plants may have a major impact on reproductive performance is relatively new and not fully realized.