Drought associated poisoning of cattle in South Texas by the high quality forage legume Leucaena leucocephala.

Approximately 80 head of yearling cattle grazing on 680 acres exhibited signs of Leucaena leucocephala toxicosis, which was confirmed in 3 animals by detection of 3-hydroxy-4 (IH)-pyridone, the metabolite of the poisonous principle mimosine, in their urine. The animals had grazed leucaena almost exclusively due to lack of alternative forage resulting from drought conditions. Toxicosis from this otherwise high quality forage would likely not have occurred had animals consumed lower amounts of leucaena and could probably have been prevented, as it has been elsewhere, had the animals been colonized with Synergistes jonesii, a beneficial ruminal bacterium capable of degrading the toxic metabolites.