Traditional Male Assisted Reproductive Technologies

Males are NOT manipulated with hormones

• the best way to help repro tech with males is with sperm cells outside of the body

Females ARE manipulated with hormones

Increasing the Reproductive Potential of the Male

• Purposes of reproduction

  • Nature: looking for the survival of the species

  • Individual Animal: looking for the survival of its own genetics

  • Man: looking to produce a product (food or fiber) for his own purposes

• Assisted Reproductive Technologies or ART

  • diagnostic tool; cull nonproductive and suboptimal producing animals from our herds

  • others maximize the reproductive potential of individual animals to maximize the spread of profitable traits as quickly as possible

  • Maximize the efficiency of our production time

• In humans, performs ARTs to help couples who are having difficulty conceiving

• ARTs are not the cure for reproductive issues

Semen Analysis: a combination of gross and microscopic evaluations of semen components, each of which has a normal value for the species wer are dealing with

• Breeding Soundness Exam (BSE)

• Society for Theriogeneology recommend that all male breeding animals go through the BSE at least once a year to assess their overall soundess and sperm production

  • assessment of semen sample=reasonable chance of establishing pregnancies

    • EX:

      • concentration

      • motility

      • can the male mount

  • Best predictor of fertility is LIVE offspring

• Collection of semen sample varies a lot between species

  • EX: electro-ejaculation, mounting dummy

• Gross assessment: volume, color, consistency

  • Color:

    • ejaculate will be a whitish color=presence of a large number of sperm

    • Clear, yellowish, greenish (infection), or pinkish to reddish tinge=issue with the sample

      • Yellow: contaminated with urine or diseased state

      • Green: infection, confirmed during microscopic or culture exam

      • Pink/Red: contaminated with blood, poor collection technique, disease state, ruptured red blood cells, are toxic to spermatozoa

    • Non-opaque to clear fluid=absence of sperm

  • Consistency: highly species specific. Pigs and horses have gel fraction in their ejaculate

    • the gel is thought to be a cleansing agent to clean bacteria from the urethra after ejaculation

    • Microscopic exam: evaluate sperm concentration, motility, morphology and progressive motility. Manually or with several different electronic devices

      • Neck and Mid-piece defects indicate motility issues

      • Tail defects can be caused by temperature fluctuations (cold shock)

• Semen Analysis does not tell us whether or not the animal is fertile

• An animal with a normal analysis is much more likely to produce offspring

Artificial Insemination: the transfer of semen to the female using an artificial means

• First documented use of AI dates back to late 1700s and was performed in dogs

  • Semen rapidly declines in quality once outside of the body

    • Late 1940s > extenders

    • 1950s > cryoprotectants

• Procedure

  • Collection of semen:

    • allowing the male to mount a female but redirection of the penis into a collection device

    • collection off a dummy

    • electro-ejaculation

    • digital manipulation (very common in canines)

  • Semen preparation: within minutes or risk of loss of all viability. Prepared for fresh extended use, cooled or cryopreservation

  • Perform AI procedure

    • need to know female anatomy. Cervix, rate-limiting factor

      • pass AI rod through cervix: work well in species, which have a larger vaginal fault

• Why use AI instead of natural reproduction?

  • maximize females impregnated

  • don’t need to have a male on site

  • lower production costs

  • purchase superior genetics

  • shift breeding schemes rapidly

Semen Extension and Cryopreservation

• Unprepared sperm cells die relatively quickly outside of the body

  • drastic shift in temperature that causes the release of what are termed shock proteins that lead to cellular apoptosis

  • Large number of rapidly metabolizing cells in a small volume of fluid, so they rapidly change the pH in the fluid leading to cell death

  • Exposure of the cells to light also sets off the shock proteins leading to cell death

• How do we solve the problem

  • extend the semen; the extension fluid has a series of buffers, nutrients, salts, antibiotics, and protein-based cryoprotectants in them

    • Extender

      • buffers: solve the issue with pH caused by cellular metabolism. The salts create osmotic balance

      • Nutrients “feed” the cells. Sugar fructose. Metabolism prefers is over glucose

      • Antibiotics: kill bacteria

      • Freezing Extender has cryoprotectant. Proteins from chicken egg yolk, milk, etc. (albumens)

• Freezing or cryopreservation of cells has become the most common practice for the long-term storage of gametes

• Half the sperm motility will be lost at freezing

  • species that do not freeze well; horses and pigs

    • require us to do very high-tech procedures like intracytoplasmic sperm injection (ICSI) to maximize their sperm’s reproductive potential

      • over time, horses have gotten better at having sperm frozen because of breeding practices

Why should the producer care?

• have been the backbone of progressive facilities for almost 75 years

• the ability to maximize a sire’s potential and spread his genetics to literally thousands of offspring in a single breeding season has changed the landscape of production agriculture

• even in those programs that choose