Be aware of nitrate toxicity

Farm Forum

This year’s weather patterns provide drought concerns throughout the region in South Dakota. As such, it is more than appropriate for producers to think about the risk of nitrates in feed supplies and how it will affect their livestock operations. It is well known that certain plants are nitrate accumulators and can contain toxic levels of nitrate when consumed by cattle and sheep; some examples are:

1. Small grains

2. Corn

3. Sudangrass

4. Sorghum

5. Millet

6. Bromegrass

7. Orchardgrass

8. Tall Fescue

9. Sweet-clover

10. Alfalfa

Nitrates reduce animal performance, and if concentrated enough will lead to death of some animals. Performing a Nitrate Quick Test will help producers to determine whether or not they might have problems with nitrates. If a test indicates they are in risk it may be prudent to further proceed with laboratory analysis. The Quick Test can be accomplished to establish the levels of nitrates present, or not present, in the plant.

Proper sampling is critical to have the best accuracy results. It is important to know that where livestock are allowed access to forage for a limited amount of time, testing the upper portions of the plant is recommended. If livestock is in a rotational system, sampling should focus more on the lower third of the forage where higher concentrations would be expected.

When dealing with nitrates never forget to:

• Consider field variation before cutting

• Take multiple samples within your field (at least 15 samples)

• Always cut at ground level

• When collected, samples should be placed in a paper bag. Deliver your samples to a lab the same day, or if you need to ship them use ice packs to prevent mold build-up (Be sure to ask your shipping company about their preferences in shipping material).

• Consider nitrates in water as well since high levels can turn deadly for livestock.

Most of the preliminary testing can be done at any SDSU Regional Extension Center using a “Nitrate Quick Test Kit.” However, this test will only recognize the presence or absence of nitrates in plants. To see and understand the actual levels of nitrates, samples should be send to a private laboratory (