The Mare

¨       21-day estrous cycle

¨       Estrus lasts 5-7 days

¨       Time of ovulation: 1-2 days before the end of the heat period

¨       Ovaries

¨       Mare will typically exhibit heat when she has developed a follicle 2.5-3.0 cm in diameter.

¨       Follicles grow at a rate of 0.3-0.5 cm per day.

¨       Generally ovulate when 4.0-5.0 cm in diameter.

¨       Uterus - endometrial folds enlarge and become edematous. Uterus feels thickened, heavier and doughy.

¨       Cervix - soft and broad when fully relaxed. Progressively flattens and sinks to vaginal floor.

¨       Vaginal wall - pink, bright pink to red as estrus progresses. Increasing moistness.

¨       Mares receptive to advances of stallion

¨       Signs supporting receptivity to stallion

¨       Elevated tail raise

¨       Winking

¨       Eversion of vulvar labia

¨       Most consistent sign of sexual receptivity (heat)

¨       Leaning

¨       Squatting

¨       Standing still

¨       Urinating

¨       Diestrus - 14-16 days

¨       Mares reject advances of stallion

¨       Ears back

¨       Kicking

¨       Swishing tail

¨       Moving back & forth

 

Inseminating The Mare

¨       Assemble all equipment

¨       Restrain mare

¨       Wrap tail

¨       Wash and rinse (3 times). Always begin washing at vulva and continue outwards (or expanding) circular pattern.

¨       Dry with paper towel

¨       Draw semen into syringe/pipette

¨       Put on sterile sleeve

¨       Apply sterile lubricant

¨       Introduce hand/pipette into vagina

¨       Place index finger into cervix & guide pipette through cervix

¨       Withdraw finger from cervix and hold cervix closed around pipette

¨       Deposit semen into the uterus by depressing syringe plunger

 

The Stallion

Building the A.V.

¨      Pressure

¨      Neural stimulation

¨      Water bladder

¨      Weight   9-11 lbs.

¨      Temperature

¨      111-122oF (44-50oC)

¨      Maintained for period of time

¨      Lubrication

¨      Type

¨      Quantity

 

Collection

1.      Tease Mare

¨      In heat, allow mounting

¨      Properly restrained (hobbles, tease rail)

2. Stallion

¨      Tease mare

¨      Obtain erection

¨      Handled properly

3. Washing

¨      Warm water 42oC (108oF)

¨      Clean container

¨      Safety

¨      Preputial ring

¨      “Bean” in fossa glandis and urethral sinus

4. Tease

¨      Again

5. Final A.V. Preparation

¨      Adjust pressure

¨      Check temperature and lubrication

6. Mounting

¨      Tease mare or phantom

7. Presentation of A.V.

¨      Deflect penis into A.V.

¨      Proper angle

¨      Resistance

8. Ejaculation

¨      Flagging

¨      Slowly lower A.V.

¨      Remove A.V.

9. Release Water from A.V.

 

Semen Handling & Evaluation

¨      Remove collection bottle

¨      Remove gel filter

¨      Pour semen into warm cylinder

 

Volume

¨      Total volume

¨      Gel-free volume

¨      Sperm rich portion

¨      (15-300 ml)

 

Motility

¨      Percentage of motile cells

¨      Total (0-100%)

¨      Progressive (50-90%)

¨      Warmed slide

¨      Diluted semen (1:20=0.25 ml + 4.75 ml)

¨      Microscope-heated stage

 

Concentration

¨      Estimating number of spermatozoa

¨      Densimeter

¨      Zero-formalin solution

¨      Add semen

¨      Mix

¨      Read sample

¨      Million/ml