Cyanide and Nitrate Poisoing in Cattle

8/7/2019 Cyanide and Nitrate Poisoing in Cattle

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CYANIDE AND NITRATE POISONING IN CATTLE

SEMINARSEMINAR

ONON

Presented by:

Umesh Sontakke



CYANIDE POISIONING



Cyanogenic glycosides:

Cyanide poisoning occur in animal due to cyanogenic glycoside present in

certain plant

Cyanogens are glycosides of sugare & a cyanide containing aglycone.

21 cyanogenic glycosides are known

Distributed in 250 plant Genera & 1000 plant species



Cyanogenic plant mg CN / 100 gm plant tissue

Sorghum 250

wild cheeries 140 -370

Arrow grass 77

Lima beans 10 - 300

Bamboo tips 800

Linseed meal 53

CYANIDE CONTENT IN CYANOGENIC PLANT

(Montogomery 1980; Kingsbury 1964)



cyanogens of importance in animal nutrition

AMYGADALINEThis glycoside found in Rosaceae such as-

1 chokecherries.

2 wild cheries

3 Mountain mohagany

4 Kernels of apricorts, almonds,peaches,apples etc..

DHURRIN

Occure in sorghum species

1 sorghum grain & its forage

2 sudan grass,johanson grass

LINAMARIN

Found in white clover, flax (linseed),cassava, lima beans.

Sorghum varieties have cyanide potential between 400 and 900 ppm on a dryweight basis. (John et al. )



Metabolism

HCN is formed when these glycosides are hydrolyzed by plant enzymes in

following steps

1 cyanogenic glycosides Sugar + aglyconeB-glycosidase

2 Aglycone HCN +aldehyde or ketoneHydozynitrile lyase

Glycosides occur in vacuoles in plantBeta glycosidase enzyme are found in cytosol

Damage to plant from trampling, mastication,frost,drought

Result in enzymes & glycosides coming together

HCN is formed



LINAMARIN

CH3

|Glucose-C-CN

|

CH3

LINAMARIN

HCN+ Glucose +

CH3

|C=O

|

CH3

ACETONE

(Peter R .Cheekk 1985;)

B-glycosidase



HCN

ENTER S INDIVISUAL TISSUE

INHIBIT CYTOCHROME OXIDASE

ATP FORMATION CEASES

ENERGY DEPRIVATION

DEATH



SIGNS OF CYANIDE POISIONG

DYSPNEA

EXCITEMENT

GASPING

STAGGERING

PARALYSIS

CONVULSION

COMA

DEATH



DETOXIFICATION

Cyanide readily detoxify by Liver, kidney, thyroid tissue as they have

³R HODANASE´ (Thiosulfate sulfurtransferase) enzyme

S2o32-

+ CN - SO2-3 + SCN

thiocyanate

Thiocyanate is excreted in urine.

Lethal dose of cyanide =0.5 to 3mg/kg body weight

R HODANASE



TREATMENT

Injection (i/v ) of sodium thiosulfate & sodium

nitrate

Dose: cattle- 3 gm sodium nitrate

15 gm sodium thiosulfate200 ml water

Nitrate methaemoglobin

Methaemoglobin combines with cyanide because of

more affinity than cytochome oxidase



The golden rules for using sorghum crops for fodder are:

Avoid grazing stressed (droughted) plants and in particular, avoid regrowthsuch as crops ratooning as a result of storm rain.

Delay grazing until plants are over 45 cm high for shorter varieties or over 75 cm high for tall varieties. This greatly reduces the risk of cyanidepoisoning. Plants forming flowers or grain are least likely to poison stock.

(John D. Bertram, )



Watch your stock continuously for the first hour and then frequently for the first

few days. Make a point of checking on them at least twice a day

Keep a supply of sodium thiosulphate on hand for emergency treatment of cyanide poisoning.

Supplement stock on sorghum crops with sulphur (10% sulphur in a salt lick).Sulphur is required for detoxifying cyanide in the rumen and liver andsorghums are generally low in sulphur.

For fodder conservation, don't make hay from sorghums that are consideredunsafe to graze. Ensile them. Get hay or silage samples tested for cyanidepotential and nitrate before feeding out.

(John D. Bertram, )



Nitrate poisioning

� Nitrate in itself is not toxic to animals, but at elevated levels it causes

a condition called nitrate poisoning.

� Nitrates are normally found in forages are converted by the digestion

process to nitrite, and in turn the nitrite is converted to ammonia

� If cattle rapidly ingest large quantities of plants that contain high levels of

nitrate, nitrite will accumulate in the rumen.

� Nitrite is ten times (10 X) as toxic to cattle as nitrate.



MEAN NITRATE CONTENT IN SOME COMMON FEEDS

(Kapoor et al.)

FEEDS/FODDERS

NITRATE CONTENT

(% KNO3)

FEEDS/FODDERS

NITRATE CONTENT

(% KNO3)

Maize grain 0.185 Doob grass 0.227

Barley 0.206 Berseem 0.038

Wheat bran 0.119 Lucerne 0.068

Rice bran 0.179 Maize green 0.100

Groundnut

cake

0.237 Mustard

green

Traces

Mustard cake 0.228 Oat green 0.098

Wheat straw 0.090 Bajara green 0.325

Paddy straw 0.22 Cow pea 0.033

Oat silage 0.057 Jowar green 0.044



FATE IN RUMEN

NITRATE & NITRITE IN PLANTS

PLANTS FEED TO ANIMALS

NITRATE S CONVERTS INTO NITRITES

NITRITES OXIDISES Hb Fe3+ to Fe 2+

METHAEMOGLOBINE



The pathways of nitrate metabolism in the rumen

Overall reaction

� NO3-+2H+ H2O+NO2

- --------------------1

� NO2-+6H+ H2O+ NH3 -------------------2

3HCO-2+NO2

-+5H+ 3 CO2+NH+4+2H2O ---------- 3

� 3H2+NO2-+2H+ NH+

4 +2H2O -----------4

� 3HS- + NO2- +5H+ 3S0 + NH+

4 +2H2O



Signs & symptom

ANEMIC ANOXIA

DYSPNOEA

GASPING

RAPID RE

SPIRA

TION

A RAPID FEABLE & WEAK PULSE

MUSULE TREMORE

WEAKNESS

STAGGERING GAIT



TREATMENT

METHYLENE BLUE:

Converts back fe 2 + Hb to fe3+

Pig & horses: 1-2 mg/kg body weight ., i/v

Cattle & sheep : 20mg/kg body weight ., i/v

Repetation of treatment is recommended as necessary at 6-8 hr intervals

(Jones 1988)



INCLUSION OF NITRATE IN DIET

Toxicities from nitrite accumulation in and absorption from the rumenappeared to be the major constraint to replacing urea with nitrate in lowprotein diets

Nitrite accumulation in the rumen only occurs where nitrate is introducedabruptly and in excessive amounts.

The rumen microorganism can readily adapt to nitrate as a source of

fermentable N (Megasphera elsedenii )



Conti«

� Sheep on high energy diets supporting high growth rates were unaffectedby adding 3.4% nitrate to their diets.

� Dairy cows producing 16-19L milk/day were unaffected by inclusion of 2% nitrate in feed (Farra and Satter, 1971)

� Sulphur balance was effected by nitrate inclusion in sheep fed concentratediets.

� Additional Mo in a diet boosted nitrite production from nitrate. Mosuppresses sulphur reducing bacteria and production of hydrogen sulphidein the rumen

Cyanide and Nitrate Poisoing in Cattle

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