Nitrates

[cowman]

I'm no expert on this but just wanted to let people know high nitrates can be a real problem this year. There is a large outfit in my area that baled up all their crops for greenfeed. When they got it tested it was very high in nitrates and would have killed their cows big time. They are mixing it with other stuff and are able to get the numbers down to an acceptable level. So get those drought-stressed crops checked.

[Quasi]

There is a very little known solution to nitrates in forage crops. If you suspect a nitrate problem and have access to a silage bagger - go for it. The oxygen free fermentation converts nitrates to "If I remember right" - nitrites - an acceptable form. I trust that's the correct chemical terminology. I do know that what ever it does it converts the problem to a benefit.

[chalmers]

In ruminants nitrate is converted to nitrite by bacteria in the rumen, the nitrite is then changed into ammonia, excess is absorbed by the blood and passed in the urine as urea. If ruminants consume high nitrate feed and it can't be immediately converted to nitrite then ammonia and expelled in the urine, the levels of nitrate and nitrite accumulate in the rumen. Nitrate poisoning occurs when the NITRITE level exceeds the capacity of the microbes to convert it to ammonia. It is the NITRITE that combines with the hemoglobin to form methemoglobin which does not allow the transport of oxygen to body tissues. Also nitrates can be converted to nitrites in heated feeds by microbial action. Nitrites in a feed are 10x more toxic than nitrates. Ensiling can reduce nitrate levels but not without a drop in silage quality. Therefore, if good silage is put up and there is a rapid fermentation process, the rapid drop in pH does not promote the rapid degradation of nitrate during the ensiling. This means that checking silage nitrate levels when the pit is being filled, usually provides an accurate indication of what the nitrate level will be later on. The bottem line is that producers should not assume that the ensiling process will make high nitrate feed safe, they should test and blend it off accordingly. Hope this helps, Alberta Agriculture's Agdex 400/60-1 gives the full explaination and is where I got this info from.