Breeding Management and Assisted Reproduction

  1. Artificial Insemination

    1. Dose
      1. 500 million Normal Motile Cells

    2. Semen Extender
      1. Kenney Extenders/Skim Milk
      2. Antibiotics

    3. Protect Semen
      1. Light
      2. Heat/Cold
      3. Air
      4. Blood/Urine

    4. Intrauterine Insemination
      1. 35 mm follicle or greater
      2. Give HCG
      3. Breed before ovulation
      4. Deposit semen in uterus via cervix
      5. Avoid syringes with siliconized rubber (ie most of them)

    5. Multiple Horses
      1. An ejaculate of 10 billion normal cells could breed 20 mares (10/0.5=20)
      2. Check breed restrictions

  2. Chilled Semen

    1. Overnight or Same Day Delivery
      1. Airlines
      2. Fed Ex

    2. Problems
      1. Stallion Collection Schedule
      2. Palpating the mare at MWF or every day
      3. Judging the timing
      4. Shipping Delays
      5. Cost per breeding

    3. Methods
      1. Equitainer
      2. Styrofoam boxes

    4. Breed Restrictions
      1. Not all breeds or stakes programs allow this

  3. Frozen semen

    1. Egg Yolk and Other Extenders
      1. Prevent ice crystal damage to membranes
      2. Store semen in straws in liquid nitrogen
      3. Lasts "forever"
      4. Can breed to a dead stallion

    2. Problems
      1. Variable post thaw motility between stallions
      2. Not all stallion semen freezes well
      3. Usually survives 8 hours or less in mare
      4. Need to breed within 8 hours of ovulation

    3. Breeding Procedure
      1. Read thawing instructions that come with straw
      2. Protocol (there are alternatives)
        1. Ultrasound every day until follicle >35 mm
        2. Give 2500 IU HCG
        3. Ultrasound/palpate every 8 hours for ovulation
        4. If she ovulates, breed her
        5. If no ovulation by 32 hours, breed at 36 hours
        6. Continue to check for ovulation
      3. Very labor intensive
      4. Much more difficult than breeding cows with frozen semen

  4. Embryo Transfer

    1. Advantages
      1. More than one foal per year
      2. Mare can keep showing
      3. Risk of birthing borne by recipient

    2. Outline of procedure
      1. Synchronize donor and recipients (P an E)
      2. Lots of recipients helpful
      3. Flush at 7 days post ovulation
      4. Ideally want unhatched blastocyst (more hardy)
      5. Implant into recipient
        1. Surgically
        2. Transcervically

    3. Success rates
      1. Variable
      2. 50% of flushes to get an embryo
      3. 50% of embryos implant successfully
      4. Therefore one pregnancy for every four flushes

    4. Commercial ET
      1. Large farms with many recipients
        1. Texas
        2. Colorado
      2. Send flushed embryo by courier in equitainer
      3. Cost is about $4000+ per pregnancy

  5. Breeding Management

    1. General
      1. Make sure mare is cycling before you breed her
      2. Accurate and thorough records is essential

    2. Records
      1. Teasing
      2. Palpation/ultrasound records
        1. left ovary/right ovary U C E F
        2. record follicular development and size
        3. record breeding,name of stallion, semen parameters, HCG given?
        4. record day of ovulation (CH detection)
        5. record if fluid in uterus post breeding
        6. record preg check 14 days post ovulation
        7. record preg check at 21, 28, 35. 60, 90 and 120 days
        8. record foaling date
        9. etc

    3. Tease, Tease, Tease
      1. tease mares every day or MWF
      2. Start palpating mares when they come in heat
      3. identify those mares that show heat for only one day
      4. pregnant mares should not return to heat

    4. Injections
      1. PGF - given in diestrus to bring mare into heat
      2. HCG - given in estrus (35mm follicle) to make mare ovulate
      3. Oxytocin - given post breeding to make mares dump out excess uterine fluid