Chapter 14: Artificial Insemination

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Chapter 14 Artificial Insemination

• Chapter overview
• Chapter 14 presents the development and
  utilization of artificial insemination (AI)
• history and development of AI
• impact on the animal breeding industry
• anatomy and physiology related to AI

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Artificial Insemination

• Introduction of semen collected from the male
  into the female reproductive tract by a method
  other than natural mating

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Why Artificial Insemination?

• Greatest value genetic improvement
• Allow the best animals to be mated regardless of
  distance separating them
• Increase availability of superior genetics
  (semen) at an affordable price

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History of AI

• Arab use for horses 1322
• Spallanzani priest in Modena, Italy (also
  "freezing observations")
• Reptiles 1777
• Dogs 1780
• Hunter, first human AI, in England 1785
• Millais, in USA, used in dogs - 1884
• Ivanoff, in Russia 1899 pioneer in birds,
  horses, cattle, sheep

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History of AI (continued)

• World's Fair in New York 1939, successful AI of
  Jersey cow at fair, bull was on exhibition at San
  Francisco Fair
• First American AI cooperative - 1938, New
  Jersey
• Freezing (British) 1949, lab accident led to
  discovery of glycerol for freezing
• Frozen boar semen (Minnesota) 1970

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Are their limitations to AI?

• AI can quickly disseminate undesirable genetic
  traits if appropriate testing is not completed
• Special training and equipment is required to
  collect animals, handle semen, and inseminate

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Reproductive Cycle Timetable
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Reproductive Cycle Type
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Collection for AI

• False mounts increase output
• Natural service versus female in heat or mounting
  dummy
• Vaginal collection centuries old
• Artificial vagina Russian development in 1930
  common use for cattle, sheep, horses
• Mechanical manipulation used with injured sires
  or sires unwilling to mount
• Electroejaculation used with injured sires or
  sires unwilling to mount

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Evaluation of Semen

• Semen is evaluated for characteristics indicating
  viable sperm, to include
• General appearance of semen sample
• Enumeration of sperm by indirect method such as
  colorimetry
• Motility (movement) and dead-alive ratio of sperm
  by microscopic observation
• Morphology (form) of sperm by microscopic
  observation

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Extension of Semen

• Extenders are added to increase volume to allow
  desired number of services (up to 500 per natural
  collection for some bulls)
• Egg yolk (first used in 1930s)
• Gelatin (Danish system)
• Sterilized milk (predominates in US)
• Fruit or vegetable juices (limited use)
• Blood plasma or serum (research use only)

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Other Additions to Semen

• Antibiotics - most extenders have additions to
  control bacteria
• Colors - often added to identify breed of animal
  or organization selling the product
• Glycerol - to prevent ice crystals from forming
  in sperm

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Fresh Versus Frozen Use

• Fresh semen was utilized before freezing
  techniques were well established
• Fresh semen is currently the primary source for
  AI in swine
• Frozen semen can be stored indefinitely in liquid
  nitrogen at -320o F (-196o C)
• Frozen semen is the primary source for AI in beef
  and dairy cattle

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Forms of Frozen Semen Storage

• Ampule - glass vial containing 0.5 to 1.0 ml (cc)
  of diluted semen extensively used until
  development of the straw
• Straw - plastic straw with 0.25 to 0.5 ml (cc)
  diluted semen 95 percent of bovine market
• Pellet - aspirin-like frozen tablets limited
  use

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Use of AI

• Beef - significant use may be limited by
  management methods
• Dairy - extensive use highest dollar volume in
  industry
• Sheep - virtually no commercial use
• Hogs - fresh semen use increasing rapidly

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Use of AI

• Horses - very extensive use of fresh AI in
  several breeds some AI with frozen semen
  limited by registry organizations
• Dogs - significant increase in use of shipped,
  fresh semen some frozen
• Cats - limited due to need for electroejaculation
  collection

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Use of AI

• Poultry - extensive use in breeder turkeys
• Bees - extensive use to maintain superior strains
  of bees for honey production in apiaries
• Humans - utilized to overcome infertility