Mycotoxins

Lisbeth Espinoza and Matthew E. Smith

Hui-Ling (Sunny) Liao, Ko-Hsuan Chen, Florencia Marcon, Robert (Robbie) Jones, Brittany Justesen, Joseph Walter, Ann Blount, Cheryl Mackowiak, Doug Mayo, and Marcelo Wallau

The beef cattle ranchers in Florida reported some health issues related to cattle grazing on warm-season grass pastures, such as bahiagrass and bermudagrass. The illness was not attributable to nutritional imbalances, or other possible causes. The focus then turned to what the animals were consuming, and forages were implicated. In general, the forages in Florida are just fine, however, sometimes under certain circumstances the fungi that live in our forages may produce “secondary metabolites”. All the forage harbor fungi. Some fungi are good in that they aid our forages to grow better, helping to mine nutrients from the soil or atmosphere. Sometimes they are not so good, like when high levels of ergotized seed occur in the seed heads of bahiagrass.

Hui-Ling Liao, Kaile Zhang, Kaile Zhang, Vijay Verma, Haihua Wang, Brittany Justesen, Justesen,Brittany L., Joseph Walter, Joseph H. Walter, Valerie Mendez Stansly, Ann Blount, Cheryl Mackowiak, Marcelo Wallau, Robert (Robbie) Jones, Ko-Hsuan Chen, Ed Jennings, J. K. Yarborough, Doug Mayo, Ray Bodrey, andAaron Stam

The toxicity of grasses caused by mycotoxins has led to economic losses in the United States due to the health impact on livestock feeding on it. Florida's warm and humid weather is favorable for the growth of mycotoxin-producing fungi on grasses. The JECFA has provided evaluations and risk management for some high-risk mycotoxins; however, more research is needed in Florida to determine the maximum levels of these mycotoxins, how different environmental conditions affect these levels, and the specialized risk management to prevent animals from getting sick. Our Extension agents were able to collect and examine 195 grass samples from 13 ranchers across dry and wet seasons in Florida. In this publication, we summarized the results for our ranchers to learn more about (1) what (dominant) mycotoxins are generally present in Florida’s pastures, (2) what grass species could harbor more of these mycotoxins, and (3) what seasons or locations may favor these dominant mycotoxins.