Forage Crops 16

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Forage Crops 16

• 4310 Forage-related disorders

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Bloat

• Distention of left abdomen due to stable foam in
  rumen
• Cattle need to release gas from rumen by
  eructation (belching). Bloat is a failure to be
  able to belch
• White clover and alfalfa are worst offenders

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White clover and bloat

• White clover spreads by stolens that root at
  nodes. The leaf grows from the stolen which
  means there is not much real stem that is
  consumed by the animal.
• Lack of fibrous stem makes makes white clover
  very nutritious, but also very bloat prone!

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Prevention

• Use non-bloating legumes such as birdsfoot
  trefoil or lespedeza
• Do not turn hungry cattle in to wet alfalfa or
  clover (even dew wet)
• Feed dry hay
• Limit time in pasture during adaptation
• Dilute with grass
• Use blocks or feeds with poloxalene or
  polyoxyethylene (23) Lauryl ether
• Rumensin or Bovatec also prevent
• Cull chronic bloaters

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Bloat Treatment

• Work with vet
• Use stomach tube to administer some kind of
  defoaming agent
• Oil about a pint of vegetable oil or mineral
  oil
• Liquid poloxalene drench
• ¼ cup of mild detergent
• Rumen punch emergency procedure, but sometimes
  necessary to save the animal

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Nitrate Poisoning

• Nitrates are potentially deadly for cattle,
  sheep, goats and horses (horses not as much)
• The vegetative portion of plants may contain high
  levels of nitrates during drought or following a
  period of low sunlight
• Nitrates are converted to nitrites. Nitrites are
  absorbed in blood and attach to hemoglobin
  Makes Brown Blood
• Nitrates are especially high in forages which are
  stressed by frost, drought, insufficient sunlight
  and herbicides

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Nitrate accumulators

• Sorghum sudans
• Sudangrass
• Pearl Millet
• Corn
• Wheat
• Burmudagrass?

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Symptoms

• Abortions
• Lack of oxygen results in blue membranes around
  eyes and mouth
• Labored breathing
• Animals go down
• Fairly quickly die

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Treatment

• Usually found dead, so not much to do
• If observed early, vet can inject methylene blue

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Testing

• Nitrate screen Sulfuric acid plus diphenylamine
• Submit for laboratory analysis to obtain exact
  levels
• 2500 5000 ppm exercise caution watch for
  abortions
• 5000 15,000 ppm Dangerous, restrict feeding
  feed to less susceptible animals
• gt15,000 ppm Highly toxic

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Prussic Acid

• Prussic acid is Hydrocyanic Acid or HCN
• Johnsongrass, Sorghum-sudan, wild cherry
• Not Pearl millet
• Most common after frost
• Can occur in young plant growth following drought

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Prussic acid

• Interferes with oxygen carrying capacity of red
  blood cells
• Symptoms of suffocation, excessive salivation,
  rapid breathing, muscle spasms, death

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Prussic acid

• Prussic acid evaporates from the plant (unlike
  nitrates)
• Therefore, standing plants are safe in 7 10
  days. Hay is usually safe after baling. Silage
  is generally safe after about 3 weeks.
• Tests are available

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Grass Tetany

• Magnesium Deficiency
• Mg needed for nerve function deficiency results
  in nervousness leading to convulsions and death
• Usually happens in cows in first weeks after
  calving usually best ones in herd
• Possible in sheep, goats and mares (rarely)

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Other pre-disposing factors

• High K!
• Low P (Phosphorus low 54 of time in Tenn.)
• High N
• Wheat
• No legumes
• Cool weather
• Early spring grass growth (low in Mg, high in K)
• Can occur in fall

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Control

• Soil test dont add K unless needed add P if
  needed
• Increase salt (NaCl) if grass tetany is recurring
  problem
• Provide supplemental Magnesium

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Acute Bovine Pulmonary Emphysema (ABPE)

• Occurs when moving from dry feed to lush pasture
  or from grass to legume
• Acute respiratory distress
• Linked to L-Tryptophan (which is higher in some
  lush pastures)
• ABPE is possible, but not likely

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Ergot Poisoning

• Linked to parasitic fungus on small grains,
  Ryegrass, Bahiagrass and Dallisgrass
• Reduces blood flow to extremities resulting in
  lameness, tail sloughing
• CNS stimulation or depression, elevated body
  temp, increased respiration
• Drunk cows on dallisgrass very common in
  Tennessee and Alabama

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Bermudagrass staggers

• Ive never seen it or heard of it in Tennessee,
  so I dont plan to worry about it
• Id suggest you do the same