Artificial insemination Flashcards
2 main reasons for AI
- genetic improvement (more breeding, no geographic issues, sex preselection)
- prevent disease transmission (no direct contact, process semen)
main goal of AI
pregnancy - sufficient fertile sperm at the site of fertilization when the egg arrives
what do you need to be successful at to achieve pregnancy (3)
- semen collection
- semen extension/preservation
- insemination (semen handling, placement, timing)
3 procedures for semen collection
- electroejaculation
- manual stimulation
- artificial vagina
what is electroejaculation
pre-rectum stimulation of pelvic nerves with electrical pulses to stimulate involuntary emission and ejaculation
why is electroejaculation not the preferred method
- welfare concerns
- inferior sample quality
how to do a good job with electroejaculation
- localize stimulus to the desired area (ventral electrodes, finger electrodes)
- use minimum voltage necessary (stepwise increases, rhythmic application)
when is electroejaculation used
- wildlife/zoo collections (when anesthetized)
- one time procedure for breeding soundness exam in intractible/non artificial vagina trained animals (bulls/rams while conscious, deer/cats while anesthetized)
when is manual semen collection done
- tame enough
- ejaculation primarily in response to glans pressure
- boar, dog, rooster
manual collection of boar
- “gloved hand technique”
- boar trained to mount dummy sow –> gloved hand encircles penis, applies pressure to glans penis
- semen collected in wide jar with cheesecloth to separate off gel fraction
- takes 3-20 minutes
manual collection of dog
- mounted on a bitch or more often on the ground +/- bitch present
- penis massaged through prepuce –> prepuce slid behind bulbus glandis, penis encircled with thumb/forefinger –> dog steps over arm so penis is caudal
- semen collected into jar (sperm-rich fraction is second, just collect enough 3rd fraction to get volume)
manual collection of birds
- restrained while the area around the vent is massaged while stroking the back –> erection of phallus (protrudes above floor of cloaca) –> massaged until ejaculation
- semen collected in small cup or aspirated in tube
what is an artificial vagina
- basic design for all
- water jacket provides stimulatory temp (above female temp), pressure
- collection device attached to one end
bull and artificial vagina
- trained to mount a dummy or steer
- pre-collection stimulation sequence (sexual preparation) to maximize sperm collected each time –> “sexual preparation”
what is sexual preparation of bull
- for increasing semen collected
- watch other bulls collect –> false mount –> restraint near stimulus animal –> 2-3 false mounts –> ejaculation