HARMFULL EFFECTS OF FORAGE CROPS

AGR 302 AGRONOMY OF FIELD CROPS- II

COURSE TEACHER: Dr. S. ANANDHA KRISHNAVENI

Mr. R. VENKATESH20140040003

VENKATESH R

B.Sc. AGRICULTURE

ANBIL DHARMALINGAM AGRICULTURAL

COLLEGE AND RESEARCH INSTITUTE

TRICHY-9

What is forage?1

Quality parameters2

Anti – quality factors3

Classification4

References7

Management6

Anti – nutritional factors5

The term forages means the plants

used for feeding domestic animals.

FODDER CROPS are crops that are cultivated

primarily for animal feed. By extension, natural

grasslands and pastures are included whether they

are cultivated or not.

The capacity of a forage to supply

animal nutrient requirements.

This includes:

• acceptability (palatability),

• chemical composition, and

• nutrient digestibility.

Will the animal consume it and be able to digest it?

Once digested, will the forage provide the needed nutrients for growth

and good health?

“Forage quality is the extent to which a forage has the

potential to produce a desired animal response.”

BIO -CHEMICAL

BIO-PHYSICAL

FOREIGN MATERIAL

Fodder crops

Non - legumeLegume

Cereal

Cow pea

Tree

Desmanthus

Lucerne

Stylo

Grass

Subabul

Glyrcidia

Agathi

Acacia

Fodder Maize

Fodder

Sorghum

Fodder Cumbu

Bajra Napier

hybrid

Guinea grass

Para grass

Scientific name: Medicago sativa

Common name: In Arab known as alfalfa

In Europe called as lucerne

Belongs to Leguminosae

Origin: Introduced from the Mediterranean region

“Queen of forage crops”

Bloat producing proteins

Foam production

Bloat formation

BLOAT MEANS

ACCUMULATION OF GASES

• Remove blockage

• Pass tube into stomach

(free gas bloat only)

• Drench with anti-foaming agent: vegetable

oils, mineral oil.

• Puncture the rumen to relieve gas.

TREATMENT

PREVENTION

• Reduce amount of legume in pasture.

• Feed dry hay before letting animals out to large

amounts of succulent feed.

• Feed antifoaming agent (e.g. poloxalene) or

ionophore (e.g. Bovatec®, Rumensin®).

• Monitor animals for signs of bloat.

NITRATE POISONING

PRUSSIC ACID POISONING

Some plants are more likely to accumulate nitrates

than others.

– Annual forage crops: corn, small grains, Sudan

grass, and sorghum

– Weeds: pigweed, bindweed, and others.

– Vegetables: sugar beets, lettuce, cabbage,

potatoes, and carrots.

• Split nitrogen applications.

• Harvest forage as silage.

(nitrates are stable in hay)

• Avoid feeding high nitrate forage.

MANAGEMENT

• Sorghum family plants contain a secondary

compound called dhurrin, which is enzymatically

converted to toxic prussic acid.

• Leaves contain more toxin than stems.

• Prussic acid interferes with ability of blood to carry

oxygen, causing animals to die from suffocation.

Prussic acid can form in young

sorghum-type plants or in the leaves of

stressed sorghum-type plants.

• Avoid grazing young plants and new growth.

• Avoid grazing drought-stressed plants.

• Make sure hay is properly cured before

baling.

• Feed green chop in timely manner.

MANAGEMENT

• Application of fertilizers to Napier grass

leads to the production of high amount of

Na and  NH4 oxalate in the plant system.

• On consumption, oxalic acid is produced in

the animal system.

Oxalic acid + Ca --------- Ca oxalate (kidney stone)

• 3% threshold level.

• Toxic to non ruminants (10% of diet).

Mimosine ….microbes… 3,4 dihydroxypyridine

• Swollen thyroids.

• Lesser production of thyroxine in thyroid.

• Wilting of forage for 4 to 6 hours in sun

reduces its toxic effect.

• Soaking in water for overnight.

TOXIC CROPS EFFECTS ON THE

ANIMAL

Oestrogen Legumes Infertility

HCN Sorghum Mortality

Nitrate Sorghum Anoxia

Oxalic acid Bajra -Napier hybrid/

Napier grass

Kidney stone

Selenium Lucerne Abnormal growth of

muscles

Mimosine Leucaeana Formation of goiter

http://www.fao.org/docrep/article/agrippa/x9500e04.htm

http://www.uwex.edu/ces/forage/pubs/nitrate.htm

http://

www.fao.org/ag/agp/agpc/doc/publicat/guttshel/x5556e0l.htm

http://www.uwex.edu/ces/forage/pubs/sorghum.htm

“ANIMAL PERFORMANCE IS

THE ULTIMATE TEST OF

FORAGE QUALITY”.

How to access foragequality?

Accessing Forage Quality

14.8% CP28.2% fiber53.2 % TDN Low fiber Easily digested

5.1 % CP 31.5% fiber 53.7% TDNVery low protein decreased digestibility

8.8% CP32.8% Fiber46.3% TDNLow energy

Thank you…