Nitrate Toxicity in Ruminant
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Nitrate toxicity can occur in ruminants when they consume feeds containing high levels of nitrates, which are broken down into toxic nitrites in the rumen. Symptoms include weakness, brown mucous membranes, rapid breathing, and death from asphyxiation. Nitrate levels above 0.5% in feed are unsafe, with young animals being most at risk. Methylene blue treatment can convert nitrites back to hemoglobin. Proper forage testing and dilution of high-nitrate feeds can help prevent toxicity.
Nitrate Toxicity in Ruminant
- 1. Nitrate Toxicity In Ruminants Technical Company for Industry and Trade C.E.O Eng. Mohammad AlSaleh technovet@yahoo.com
- 2. OUTLINE -Introduction. -Objective. -Safe levels of nitrates in most feeds for ruminants. -Sources of nitrate. -Action of nitrate toxicity. -Signs and symptoms of nitrate toxicity. -Treatment. -Prevention. -References.
- 3. INTRODUCTION Nitrate poisoning is a rare but important cause of poisoning in ruminants. It can occur as the result of eating crops that contain high levels of nitrate. However, the most common source is inorganic nitrate fertilizer or via water run-off from heavily fertilized fields. Spring is the most common season for nitrate poisoning.
- 4. OBJECTIVE Highlight about Nitrate toxicity.
- 5. SAFE LEVELS OF NITRATES IN MOST FEEDS FOR RUMINANTS Feed containing 0.5% nitrates or less is generally safe for ruminants. Recent research, though has discovered that cows have had no adverse effects if nitrate levels are between 0.5 and 1%. However, subclinical or chronic nitrate toxicity can develop when levels get between 0.5 and 1% so you need to be cautious when feeding out feeds that contain these nitrate levels, especially with animals that have not become acclimatized to nitrates that are above even 0.5%.
- 7. SOURCES OF NITRATE There are several plant species that may accumulate nitrate, including the Brassica plants, green cereal grains (barley, wheat, rye and maize), sorghum and Sudan grasses, corn, beets, rape, docks, sweet clover and nightshades. Application of large amounts of fertilizer or drainage from fertilized fields and contaminated water sources can also serve as a source for nitrate. Drought can also allow accumulation of nitrate in certain plants.
- 8. ACTION OF NITRATE TOXICITY The toxic principle for all animals is nitrite. Nitrate, prior to being reduced to nitrite, is not overtly toxic to non-ruminant species. Nitrite is essentially equally toxic to both ruminant and non-ruminant species. Toxicity in ruminants is primarily seen following the consumption of high amounts of nitrate, which is subsequently reduced to nitrite by rumen microbes. Cattle, sheep and goats are the species that are most commonly affected by nitrate poisoning, with neonatal animals being at greater risk.
- 9. Nitrate poisoning occurs because the nitrate is broken down to nitrite in the rumen. In normal circumstances this nitrite is further broken down to ammonia in the rumen and is then used by the rumen microbes to make protein. However, when large amounts of nitrate are eaten over a short period of time, the nitrite accumulates in the rumen and is absorbed. Once in the bloodstream it reacts with iron in the red blood cells so that they can no longer bind oxygen.
- 12. SIGNS AND SYMPTOMS OF NITRATE TOXICITY symptoms include rapid and weak heart-beat, subnormal body temperature, muscular tremors, weakness and ataxia (as in staggered gait, disorientation, etc.). Brown/bluish-grey mucous membranes, excessive saliva and tear production, rapid breathing, frequent urination, as well as vomiting (more common in monogastric animals), diarrhea or scouring, and an inability to get back up from laying down are also frequent. Death soon follows within a few hours after animals have been fed.
- 13. The main cause of death is via asphyxiation with a lack of oxygen being supplied to bodily tissues. Subacute nitrate toxicity is often corresponding with abortions, reduced weight gain, reduced feed intake, reduced milk production, increased susceptibility to illness and infections, and reproductive problems such as silent heats and reduced fertility. Often signs and symptoms of subclinical or chronic nitrate toxicity go unnoticed or are not related to feed quality.
- 14. Animals can go without showing signs of distress for several days to several weeks while consuming nitrate- containing feedstuffs. By this time they can appear belligerent, uncoordinated, develop diarrhea, eye lesions, and symptoms similar to pneumonia, such as interstitial pulmonary emphysema (fluid accumulating in the lungs). Prolonged exposure to nitrate-containing feeds coupled with cold stress and poor nutrition can lead to downer cow syndrome.
- 15. (A)Brownish mucosa of conjunctiva. (B) Brownish mucosa of vaginal vestibule. (C) Chocolate-colored blood. (D) Cherry-like colored skeletal musculature. (E) Cherry-like colored myocardium. (F) Brownish lung. (G) Glass blade with positive result in diphenylamine test in forage (elephant grass) used to feed the cattle.
- 16. TREATMENT Methylene blue is a specific treatment for nitrate toxicity. It causes a rapid conversion of methemoglobin to hemoglobin. The dose of methylene blue is reported as 4-30 mg/kg IV of a 1% solution to be given as soon as clinical signs are identified.
- 17. PREVENTION Prevention of nitrate poisoning is best achieved by controlling the type and quantity of forage offered to livestock. Avoid forages with potentially toxic levels of nitrate or at least dilute them with feeds low in nitrate. When in doubt, have feeds and forages analyzed for nitrate before grazing or feeding them.
- 18. REFERENCES •Daniel Amaral Gontijo1* Andressa Afonso Borges1 Flademir Wouters2. Nitrate/nitrite poisoning in dairy cattle from the Midwestern Minas Gerais. 2017. •Chanhee Lee and Karen A. Beauchemin. A review of feeding supplementary nitrate to ruminant animals: nitrate toxicity, methane emissions,and production performance. 2014. •Anil Kumar Puniya, Rameshwar Singh, Devki Nandan Kamra. Rumen Microbiology: From Evolution to Revolution. 2015.
- 19. Thanks