rumen acidosis liver abscess polioencephalomalasia, or polio, or pem, or “brainer” nitrate...

Rumen acidosis liver abscess

Polioencephalomalasia, or Polio, or PEM, or “Brainer”

Nitrate poisoning

Nutritional Disorders in Beef Cattle

Feedlot: Acidosis and other “digestive” problems

AcuteLaminitis, founder

Hopelessly off-feed

Sell immediately

Chronic or subacuteA little off feed,

poor performers

Long term effectRumenitis: more problems as

we have longer fed cattle – calf-feds, Holsteins, Japanese

Probably bigger problem in the PNW with barley, wheat and potato feeding

Best symptom is liver abscesses (Fusobacterium necrophorum; Actinomyces pyogenes)

Its all about bunk management !!

Ruminant system of carbohydrate digestion and absorption: Effect of feeding grain

Acidosis symptoms

variable feed intake (symptom and cause)

feces: loose – splattering, less than 1” high, no dimpling/concentric rings

lack of cud chewing

hoof lines, abnormal hoof growth

dairy: milk fat inversion

beef: liver abscesses

Acidosis

• Indicates rumen insult• Grows .25 inch (6 mm) / month

Liver Abscess Classification

O A -

A A +

A+ Liver Abscesses, 1990 to 1999

02468

10121416

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

Ave.

% Abscess

SteersHeifersHolsteins

sbl 00

Total Abscesses by Month, 1990 - 1999Tylan Fed Steers, All Districts

02468

1012141618

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg

% Abscess

90-98 Avg.1999

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EFFECT OF RUMENSIN PLUS TYLAN ON LIVER ABSCESS INCIDENCE

CONTROL RUMENSIN +TYLAN

NO. HEAD 976 1937

% A- 7.7 5.4

% A 8.4a 3.5b

% A+ 20.1a 3.5b

TOTAL 36.2a 12.4b

LAUDERT, 1990, 4 TRIAL SUMMARY ab (P<0.02)

Classically associated with periods of rumen digestive upset

◦ irregular feed intake◦ Consumption of moldy feed◦ Lush highly fermentable forages – rapeseed forage

Classically considered to be thiamine deficiency◦ Usually from presence of thiaminases◦ Administer thiamine – oral or injectible

Polioencephalomalasia, or Polio, or PEM, or “Brainer”

Symptoms:◦ Laminar cortical necrosis (brain damage)◦ Blindness◦ Staggering◦ Down◦ Seizures

◦ Recent understanding: high dietary sulfur is a predisposing factor: rumen bacteria convert sulfur to hydrogen sulfide, enters the blood, interferes with energy metabolism, “starves” the CNS

Polioencephalomalasia, or Polio, or PEM, or “Brainer”

Current issue is with corn byproducts – wet milling involves softening the grain with sulfuric acid◦ Inclusion of high levels of corn gluten feed or corn distillers

grain can increase risk of PEM◦ Low rumen pH increases production and absorption of sulfide◦ No amount of dietary thiamine can completely eliminate the

risk – may reduce the incidence

◦ Formulate diets to have 0.4% Sulfur (or less)

Polioencephalomalasia, or Polio, or PEM, or “Brainer”

Nitrate poisoning Ruminal conversion of nitrates in plants to nitrites (instead

of ammonia to microbial protein), enters blood, binds with hemoglobin to form methemoglobin, reduces oxygen transport to cells.

Formation of methemoglobin is normally reduced (via electron donation) by protective enzyme systems:◦ e.g., NADH methemoglobin reductase (cytochrome-b5

reductase)

Nitrate poisoning, cont Symptoms:

◦Respiratory distress◦Incoordination◦Weakness◦muscle tremors◦Collapse - dead

◦Don’t stress affected cattle!

Nitrate poisoning, cont Common feeds:

◦ Stressed crops (drought, frost, hail)

◦ Cool, overcast climate

◦ Lower portion of stem/stalks of certain plants: pigweed, sorghum, corn, Sudan grass, barley and oats

◦ High N fertilizer

◦ Immature more than mature forages

15 to 45 g of Nitrate per 100 pounds body weight – from feed and water◦1% nitrate in forage DM◦1,500 mg/ml nitrate (ppm) in water

Younger cattle are more susceptible

Category

NO3 NO3-N KNO3

Remarks

1 <0.5 <0.12 <0.81 Generally safe for beef cattle and sheep

2 0.5 - 1.0

0.12 - 0.23

0.81 - 1.63

Caution - some subclinical symptoms may appear in pregnant horses, sheep and

beef cattle

3 1.0 0.23 1.63 High nitrate problems - death losses and abortions can occur in beef cattle and

sheep

4 <1.23 <0.28 <2.00 Maximum safe level for horses. Do not feed high nitrate forages to pregnant

mares.