Freeze-Damaged Forages Bear Watching

Many agronomists and Extension livestock specialists have said they view raising cattle and calves as a by-product of the real crop, which is grass.  They urge producers to do the same – take care of the grass, and the grass will take care of you.

This season’s first freeze has been late, but when it comes, it will produce important changes in the forage cattle are consuming.  In some cases, changes in plant metabolism and composition can poison livestock, said Bruce Anderson, Nebraska Extension Forage specialist in a publication this week.

Sorghum and sorghum-related plants like cane, sudangrass and shattercane can be highly toxic for a few days after the first frost, Anderson said.  Freezing breaks cell membranes, allowing the chemicals that form prussic acid, or cyanide, to mix.

The fix is simple.  Prussic acid soon turns to gas and evaporates, so waiting three to five days after the first freeze before grazing sorghums reduces the chances of prussic acid poisoning greatly.




Some plants don’t die with the first freeze, but the cold will slow their metabolism.  The stress sometimes permits nitrates to accumulate in plants that continue to grow.

This usually isn’t a problem for grazing animals, but it can be an issue in green chop or hay cut right after a freeze.

When alfalfa experiences temperatures close to 20 degrees, it wilts, and nitrate levels can increase.  Freezing also makes the plants more likely to cause bloat for a few days.




A cold storm sweeping out of Canada is expected to bring wind chills as low as 17 degrees in some parts of the Dakotas today and wind chills around freezing in Des Moines and Chicago on Thursday.

Ambient temperatures today are forecast to be around 30 degrees for much of the western two thirds of North Dakota.  There is even a chance of snow in the 12-hour forecast from the National Weather Service for eastern North Dakota and northeastern South Dakota.

Frost and freeze warnings have been issued for parts of the Central Plains states over the next few days, but such conditions are not expected to be extreme, nor are they early.

Livestock will be stressed by the sudden turn of events, but aside from increased respiratory issues, the direct effects likely will be small.  A few of those that are chronically ill may die, but this happens every year.

The complicating factor for cattle producers and feedlots will be the rain that is forecast for Friday and Saturday in the Southern Plains.  While the moisture is expected to help wheat growth and pasture conditions, it could cause issues with wet cattle.




Cash fed cattle markets in the Plains Tuesday were steady to firm, compared with last week.  Trades at $138 per cwt were reported in Kansas and Texas, steady with the bulk of last week’s trade. No action was reported in dressed markets.

Wholesale beef prices Tuesday were higher, with the USDA choice cutout value at $217.95 per cwt, up $0.89 on the day, and its select cutout at $211.07, up $1.38.

The choice/select spread narrowed to $6.88 from $7.37 on Monday, and there were 76 loads of fabricated product sold into the spot market.

The CME Feeder Cattle Index for the seven days ended Monday was $193.99 per cwt, up $0.31.  This compares with the Oct settlement Tuesday of $192.60, down $1.07.