The possible arrival of the first widespread killing frost in Western Canada this week has implications for livestock producers looking to maximize feed quality for their animals.
Freezing temperatures can cause nitrates to accumulate in cereal species grown for greenfeed, which can be toxic to cattle (more info here on the SaskAg website.) However, management considerations should not be based solely on nitrate levels, says Murray Feist, ruminant nutrition specialist with Saskatchewan’s Ministry of Agriculture.
“Even though we place some emphasis on nitrates, I think we weigh too heavily on what nitrate accumulation can be,” he says in the interview below. “We still have to capture the best quality forage that we can. Having high nitrate straw is of no benefit to anybody.”
With alfalfa, nitrate levels are less of a concern, but grazing after a frost can cause problems with bloating and lead to increased winterkill, he notes.
Testing is critical for making management decisions following frost, says Feist.
“Feed testing is the best way to get a handle on what you actually have in the stack and what’s going to be given to the animals,” he says. “It’s not a very expensive test, it provides some numbers and gives you something to gauge against.”
Listen to Murray Feist’s conversation with Kelvin Heppner:
If you can’t see the audio above, listen to it on SoundCloud.