Is Millet a Problem in the Pasture?

Q. I am considering moving my two mares to 10 acres of land that had been planted with millet feed last spring. Because of the lack of moisture, the millet only grew to be about five inches high, then dried out and died. I am going to wait and see what comes up in the 10 acres this spring, but I'm wondering if it would be bad for my horses to graze on if it came up again in the 10 acres?



A. I assume that the millet you are referring to is pearl or horse millet (Pennisetum glaucum) and not red millet that is a Sorghum species. The pearl or white millet is often grown as birdseed and is not likely to be a problem to horses unless there was a heavy seed crop and the horses over-ate the seed. Some species of millet cause problems when grazed as lush pastures because they contain significant levels of oxalates. The oxalates interfere with calcium absorption and horses develop bone malformation and lameness. This has been reported as a problem in Australia, but this has not been the case in the United States.

If the plant is a Sorghum species of millet, hay from some species of Sorghum (e.g., Sudan grass/Johnson grass hybrids) has been associated with nerve degeneration of the hind legs and urinary bladder in horses that are fed the hay for long periods.

In summary, unless the millet comes up as a dominant species and there is not a mixture of grasses available to the horses, I doubt there will be a problem.

About the Author

Anthony Knight, BVSc, MS, Dipl. ACVIM

Anthony P. Knight, BVSc, MS, Dipl. ACVIM, is a professor of large animal medicine in the College of Veterinary Medicine and Biomedical Sciences at Colorado State University. He received his veterinary degree from the University of Nairobi, Kenya, in 1968. After completing a master’s degree at Colorado State University, he joined the faculty in 1974. His current professional interests include livestock heath, foreign animal diseases, emergency management, and plant toxicology. He has written two books on poisonous plants of animals in North America, and maintains a poisonous plants website for use by anyone wanting poisonous plant information.

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