FORAGE CROPS AND THEIR HARMFULL EFFECTS

1. HARMFULL EFFECTS OF FORAGE
CROPS
AGR 302 AGRONOMY OF FIELD CROPS- II
COURSE TEACHER: Dr. S. ANANDHA KRISHNAVENI
Mr. R. VENKATESH
20140040003

2. VENKATESH R
B.Sc. AGRICULTURE
ANBIL DHARMALINGAM AGRICULTURAL
COLLEGE AND RESEARCH INSTITUTE
TRICHY-9

3. What is forage?1
Quality parameters2
Anti – quality factors3
Classification4
References7
Management6
Anti – nutritional factors5

4. 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.

5. 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?

6. “Forage quality is the extent to which a forage has the
potential to produce a desired animal response.”

7. BIO -CHEMICAL
BIO-PHYSICAL
FOREIGN
MATERIAL

8. 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

10. 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”

11. Bloat producing
proteins
Foam production
Bloat
formation
BLOAT MEANS
ACCUMULATION OF GASES

19. • 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

21. 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.

23. NITRATE POISONING
PRUSSIC ACID POISONING

24. 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.

27. • Split nitrogen applications.
• Harvest forage as silage.
(nitrates are stable in hay)
• Avoid feeding high nitrate forage.
MANAGEMENT

28. • 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.

29. Prussic acid can form in young
sorghum-type plants or in the leaves of
stressed sorghum-type plants.

32. • 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

34. • 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.

36. • 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.

37. 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

38. 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

39. “ANIMAL PERFORMANCE IS
THE ULTIMATE TEST OF
FORAGE QUALITY”.

41. How to access foragequality?

44. Accessing Forage Quality
14.8% CP
28.2% fiber
53.2 % TDN
Low fiber
Easily
digested
5.1 % CP
31.5% fiber 53.7%
TDN
Very low protein
decreased
digestibility
8.8% CP
32.8% Fiber
46.3% TDN
Low energy

45. Thank you…