Main causes of nitrate accumulation in fodder crops are:

1. Use of nitrogenous fertilizers like urea, D.A.P. (diammonium phosphate) on fodder crops in more than recommended doses.
2. Adverse climatic conditions (prolonged foggy conditions, prolonged overcast/cloudy conditions, extreme cold/hot weather, frost, hail) damage fodder crops leading to accumulation of nitrate in fodders. Sudden change in weather can also cause this. In such conditions, nitrate accumulates in fodders in excess.
3. Immature fodders have higher level of nitrate.
4. Apart from fodder crops, excess nitrate can be present in animal’s drinking water.
5. Accidental consumption of nitrogenous fertilizers by animals.
6. Excess application of sewerage water or decaying organic matter to fodder crops.
7. Restriction of water intake increases the risk of toxicity.
8. Pregnant animals are more susceptible to poisoning than non-pregnant ones.

Main symptoms of poisoning are due to deficiency of oxygen in the body, and these are:

1. Rapid respiration is the predominant symptom.
2. Dyspnoea with open mouth breathing or gasping.
3. Cyanosis of the visible mucous membranes.
4. Subnormal body temperature.
5. Frequent urination, and pregnant animals can abort.
6. Muscle tremors, violent struggling, collapse, coma and convulsions.
7. Death usually occurs within a day or within few hours.

To confirm, fodder / feed should be sent to the lab.

The fodder can be got tested at any veterinary polyclinic at district level, or at the Department of Pharmacology and Toxicology at GADVASU Ludhiana.

Following measures should be taken to prevent nitrate toxicity:

1. The suspected fodder should be got tested from laboratory.
2. Nitrogenous fertilizers should be used on fodder crops only in recommended amount. Instead of using them at one time, they can be applied on fodders in 2-3 divided doses.
3. The harvesting of fodders affected by adverse climatic conditions should be delayed till the weather improves. Wait for atleast 1 week after the onset of favourable weather.
4. During cold weather, fodders should be harvested in the late afternoon after exposure to sunlight for considerable time.
5. Cut the affected fodders few inches above the ground level, as the lower stalk contains higher nitrate levels.
6. Consider harvesting and feeding high nitrate forages as silages; this decreases nitrate levels.
7. Gradually introduce cattle to suspect forages over several days.