Forage Testing ?

[Triangle Bar]

The cows have a couple of weeks of graze left, so I've been looking for some other pasture possibilities. I found a neighbor who has a couple of pivot circles that were planted to sudan grass, that he is willing to lease. He planted it late and it got maybe 12-18" of growth before he cut it. There was some re-growth but it's all froze down now.

Question
I have zero experience with sudan grass, what should I be concerned with toxicity wise or nutrient wise?

I've read that it can be dangerous for nitrates and prussic acid. Today or tomorrow I'm going to go cut some samples in different areas of the fields and send it in for analysis. Is there anything else that should be tested for?

Thanks for any replies.

 

[Mike]

If it's been 10 days after a frost, it should be OK with the Prussic acid.

Nitrate poisoning depends on how much Nitrogen has been applied recently. I would presume little, if any.

Those should be your only fears. Smart to have it tested.

 

[bverellen]

Nitrate poisoning can occur with drought stressed plants irrigardless of applied nitrogen.

The august 10th 2012 issue of AG JOURNAL had an article about this, stating that Kochia, Lamb's Quarters and forage Sorghams are susceptable and should be tested.

Abnormal concentrations of Nitrates in forage or cut feed can cause abortions or even death.

Unfortunately, the author failed journalism101 by not informing the reader just what levels are dangerous.

Sorry if this just confuses you more, Triangle Bar.

bart. †

 

[bverellen]

Some more information from Colorado Sate University:

http://www.ext.colostate.edu/pubs/livestk/01610.html

From the article:


Toxic Levels of Nitrate

The level of nitrate that causes toxicity in ruminants varies depending on rate of intake, diet, acclimation to nitrate and nutritional status. As a rule, forage containing less than 5,000 ppm NO3 on a dry matter basis is safe. Forage containing 5,000 to 10,000 ppm NO3 is considered potentially toxic when provided as the only feed. Forage containing over 10,000 ppm NO3 is considered dangerous but often can be fed safely after proper dilution with other feeds.


There's alot more to the article, and should be read in it's entirety.

HTH,

bart. †

 

[Triangle Bar]

Thanks Mike & bverellen.

Yeah bart, I've had oat hay, with no nitrogen fertilizer applied, test very high in nitrate. It seems to be more timing dependent with growth stage and drought conditions, when nitrogen is taken up by the plant for growth and then doesn't use it because of lack of water or other weather related factors.

I was kinda more concerned with my lack of experience with sudan grass and unknown (to me) problems.

After walking the ground today, there wasn't much sudan grass there (poor stand). It is mostly alfalfa, volunteer wheat & oats, and weeds. Most likely there's nothing there of concern.

 

[Triangle Bar]

The results are in.

Nitrates 1600 - marginal, limit to 1/2 of daily intake
Prussic Acid 150 - safe

That's a higher nitrate level than I guess I'm comfortable grazing my bred cows on.

That's disappointing there was enough feed to last till the 1st of the year.

 

[BRG]

Soething you could think about doing is go out every morning feed them 1/2 their daily intake. That way you know the first they eat is safe and then they can graze the rest of the day. That way you still get to use it and stretch your hay out some.

 

[Haytrucker]

Yeah, what BRG said. Either time graze the deal and feed some afterward, or better feed some before amd then turn them out til dark.
Any port in a storm.