When it comes to forages and taking forage samples, nutritional values are not the only data points that livestock owners should be aware of. Compounds like nitrates and aflatoxins can be detrimental to livestock health, and can even result in mortality.
What are Nitrates?
Nitrates are chemical compounds composed of nitrogen and oxygen, and can be found in soil, water, and are necessary for plant growth. Although they are necessary for the plant to grow, the phrase “you can have too much of a good thing” applies to nitrates when it comes to livestock forage. Excessive concentration of nitrates in forage plants can occur during cool, wet, conditions when temperatures are around 55 degrees fahrenheit, but drought conditions can also cause concentrations to reach dangerous levels, especially if fertilizers were applied. Fresh forage, such as perennial pastures and annuals, can also be sampled, which is beneficial to monitor levels during drought conditions.
Symptoms of excessive nitrate consumption involve:- Reduced milk production
- Abortion
- Staggering and tremors
- Death
What are Aflatoxins?
Aflatoxins are a type of mycotoxin that are produced by a fungus called Aspergillus flavus. When consumed by susceptible animals, they can cause hemorrhages, reduced feed intake, bloody diarrhea, and even death in some instances. These toxins can also present danger to humans if they are consumed, which is why there are different tolerances for dairy cattle. Safe levels for actively lactating dairy cattle are less than 20 parts per billion (ppb), while safe levels for calves (< a year old) and yearlings are less than 100 ppb.
Testing forages and feed can prevent accidental intake of either excessive nitrates or aflatoxins. The North Carolina Department of Agriculture & Consumer Services provides forage and feed testing for $10 per sample and it provides nitrate and aflatoxin levels along with the nutritional values, so you know exactly what you are feeding. If you have a question about forage testing, or need a hay sample taken, contact Alex Kissinger at akissin@ncsu.edu or (919) 245-2051.
