The oat crop for one of these herds had not been irrigated. It had grown well for a while with the spring rains, but then became stressed due to water deficiency and was harvested and fed to the cows. The potential for drought in many areas of the state may put many more herds at risk says Clell Bagley, USU Extension veterinarian. Oats absorb nitrogen from the soil and convert it into a nitrate form in the plant. Oat hay which is growing well and allowed to dry well before baling is usually okay.
Drought conditions stress the oat plants and it becomes much more toxic.
If producers planted oats and then do not have enough irrigation water to finish the crop, they may decide to harvest it for oat hay and set their herd, or a herd they sell it to, up for a problem, Bagley says. The problem is worse if land was previously fertilized heavily - with nitrogen for a previous year's corn crop, with heavy application of manure or if producers are growing crops in an old dry lot area where animals were confined. Other drought stressed plants can also become toxic to ruminants, he says. For instance, sorghum, sudan hybrids, even drought stressed corn. Weeds such as Kochia, Redroot Pigweed and Lambsquarter can also become toxic.