Chapter 14 Semen Collection

    A. Objective of proper semen collection: Maximum use of superior sires

      a. Maximum number of sperm ejaculated for entire life of a sire:

      1) Maximum number of sperm /ejaculate, 2) Shortest possible interval of semen collection, 3) Maintenance of libido, and 4) Good management of sire for his long reproductive life

      b. Highest possible quality: Proper semen collection and sire management

    B. Common characteristics of ejaculate for farm animals: See TABLE 14-1

    14-1 Facilities needed for semen collection

    A. Facilties for safety of collector

    B. Earthen floor to prevent slipping

    C. Means to restrain teaser animals

    D. Easy access for semen collection

    14-2 Methods of semen collection:

    A. Taking semen from vagina with spoon or rubber breeding bag

    B. Massaging vesicular gland and ampullae by way of rectum

    C. ARTIFICIAL VAGINA

    D. ELECTROEJACULATION

    14-2-1 Sexual stimulation prior to collection with the artifical vagina

    A. Sexual stimulation effect: not well defined in boar, ram and stallion

    B. Sexual stimulation in bull:

      a. Reasons for sexual stimulation:
      1) to insure that bull will mount and ejacualte reasonably, and
      2) to insure the collection of maximum number of sperm with highest possible quality per ejaculate: See TABLE 14-2

      b. Method of sexual stimulation: By exposing bulls to teaser for several min. or 2 to 3 false mounting

    C. Increasing sex drive reduced from handling bulls in the same manner for a prolonged period of time:

      a. Introducing a new teaser animal
      b. Moving teaser animal to different area
      c. Presenting 2 teasers
      d. Allowing teaser or another bull to mount the bull to be collected
      e. Bringing new bull into the collection area
      f. Collecting semen from new bull
      g. Avoiding distraction

    D. Factors affecting sexual drive:

      a. Bulls on a high frequency of collection: need more variation in stimulation
      b. Beef bulls: exhibit less sexual drive than dairy bulls

    14-2-2 Artificial vagina: See FIGURE 14-2 and real materials

    A. Components of AV: Different shape and size by species

      a. Rigid rubber casing with an opening at 10 cm from one end
      b. Rough-textured latex inner liner
      c. Rubber band
      d. Rubber funnel
      e. Graduated glass collection tube
      f. Insulated and zippered jacket during cold season

    B. Requirements of AV:

      a. Pressure: By filling water and a little air into the space between casing and inner liner
      b. Temperature: By warm water of 45¡É at collection (temperature of water at filling: 55 to 60 ¡É)
      c. Lubrication: Around front area of liner with sterile and harmless lubricating jelly

    14-2-2-a Collecting from the bull: See FIGUREs 14-3, 14-4 and 14-5

    A. AV should be held parallel to the expected path of bull's penis, after false mounts

    B. Guide penis to the side by grasping sheath and direct it into AV

    C. Bull will thrust and ejaculate simultaneously

    D. Precautions:

      a. Prevent cold shock
      b. Protect collection tube from sunlight
      c. Avoid contamination of semen by urine, water or lubricating jelly
      d. Use a different sterile AV for each ejaculation

    14-2-2-b Collecting from the ram and buck

      Similar to collecting bull semen, using AV of smaller size

    14-2-2-c Collecting from the stallion

      AV: Leather or aluminium casing with a valve to release the pressure as the penis enters and to increase the pressure for 12 to 25 sec. before ejaculation is complete : See FIGURE 14-6 and Ref. Fig.42 of Perry (1968)

    14-2-2-d Collecting from the boar

    A. Semen collection with AV or gloved hand

      B. Pressure of glans penis is very important for ejaculation for 10 to 20 min.: In natural service, the corkscrew shaped glans penis of penis is firmly engaged in the sow's cervix: See FIGURE 14-7.

    14-2-2-e Cleaning, sterilizing and storing the AV

      Inner liner and rubber funnel: should be soaked for 5 min. in 70% ethanol after washing , and then dried under UV light in a dust-free cabinet

    14-2-3 Electroejaculation

    A. Principle: Electrically stimulating nerves to male reproductive system

    B. Uses for bulls:

      a. For crippled, aged or sexually low active dairy bulls
      b. For checking semen quality of beef bulls prior to natural breeding season

    C. Equipment: A bipolar electrode and a variable source of alternating current: voltage: 0 - 30 V, amperage: 0.5 - 1.0 A; alternating + and - rings spaced 4cm apart, running longitudinally along the electrode

    D. Semen quality as compared with AV ejaculates: larger volume, lower in sperm concentration, sometimes semen contamination by urine

    14-2-3-a Electroejaculation of the bull

    A. Restrain the bull in a chute with good footing provided

    B. Remove excess fecal material from rectum

    C. Insert lubricated electrode into rectum

    D. Stimulate electrically for 2 to 5 min: low voltage ¡æ gradual increase (a few volts at a time) up to 15 V or higher, with 4-second rest period between stimulations

    14-2-3-b Electroejaculation of the buck and ram:

    A. Gradually increase voltage from 0 to 8 V

    B. Some rams fail to respond, while others yield low quality semen

    14-2-3-c Electroejaculation of the boar

    A. Not satisfactory for routine collection of semen from boars: good semen quality but considerable discomfort

    B. Require higher V than in bull, perhaps due to insulating effect of body fat