Semen Processing and Tank Management Flashcards
list two semen organizations
- select sires
2. American breeders service
what type of matings do semen organizations do and why?
planned matings; to get best potential sire
out of 100 planned matings, how many are kept and what does that mean for AI?
only one (the most superior) is kept, this is why AI is superior
how is semen collected?
with an artificial vagina on a steer for bulls to mount
how many times a week is semen collected from dairy sires?
6 times a week
why is the artifical vagina placed on a steer?
to prevent any loss of semen, but mostly bc the bulls are big bois and would crush a female
how many times a week is semen collected from beef sires?
twice a week
list the 5 aspects of semen evaluation
- volume: 8-10mL
- concentration: 8.00x10^6-1.2x10^9/mL
- motility: greater than 40%
- morphology: less than 10% abnormal
- viability
list the 2 aspects of initial semen extension (in a straw)
- viable sperm: 3.0x10^6/mL
2. straw volume: either 0.5cc or 0.25cc
how many straws are obtained from each semen collection?
20-40, depending on amount of viable sperm and straw volume
list the 5 aspects of semen extension (in the straw)
- isotonic media
- buffer
- nutrients
- cryopreservative agent
- antibiotics
describe what the isotonic media does for semen extension, and give an example
maintains osmotic pressure, minimizes H2O movement, sodium citrate is an example
describe the role of a buffer in semen extension
minimizes pH changes (from sperm poop)
describe the role of nutrients in semen extension, and give an example
maintain sperm survival, egg yolk is an example (has everything life needs in theory)
describe the role of a cryopreservative agent in semen etension, and give an example
dulls the shape of crystal formation upon freezing so it doesn’t shred sperm, glycerol and insect blood are examples
describe the role of antibiotics in semen extension
minimize bacteria growth
what was the first method of packaging sperm for freezing?
pellets, which were weird
what is the range of semen an ampoule can hold, what was it made of, and how are they to work with?
ranges from 0.5-5.00cc, made of glass, so very hard to work with
what is the most widely accepted and used method of packaging semen and give the half and full lengths
straws, 0.25cc or 0.50cc
list and describe the 3 basic aspects of semen tank anatomy in terms of insulation
- insulation: some sort of fiber
- vacuum: provides exception insulation
- plastic neck: por conductor of temperature, which aids in insulation, but makes the tank somewhat fragile
what temperature is the liquid nitrogen of the semen tank? give celsius and farenheit
- 196 degrees celsius
- 320 degrees farenheit
list and describe the 2 aspect of holding time of a semen tank
static time: plugged, untouched
working time: opening top, in use
what is the average holding time of a semen tank?
typically 4-8 weeks, depending on the tank
what two measurements do semen tanks vary in?
volume and neck diameter
what 4 important things should be on every straw label?
- animal name
- ID
- freeze code
- CSS (certified semen services) code= ensures quality
list 3 types of semen straws and their quantities
- french medium: 0.5cc
- french mini: 0.25cc
- german straw: 0.25 cc
what does cryopreservation do to sperm and how?
kills more than 5-% of frozen sperm in straw due to ice crystal formation and osmolarity
what influences ice crystal formation?
freeze rates and diameter of straw
describe the 3 osmolarity zones in a semen straw
ice front zone: outer most ring, a hypotonic solution, sperm dead
optimal zone: in middle of straw, isotonic solution, sperm happy
solute zone: center of straw, hypertonic solution, sperm dead again
what is the key to sperm survival?
the higher the surface to volume ratio of the packaging, the faster the thaw rate at a given temperature; the faster the thaw rate, the fewer sperm destroyed by vibrations of ice crystals during the freeze-thaw process
what is the positive aspect of a higher surface to volume ratio?
sperm thaws more rapidly, meaning less time in transition from ice to liquid, resulting in less damage to sperm
what is the downside of a high surface to volume ratio?
sperm are more sensitive to temperature changes in the neck and handling
which quantity straw is better from a thaw perspective?
0.25cc
which quantity straw is widely used in the US?
0.5cc
what is the point of the sheath on the AI syringe?
to protect the animal from the stainless steel syringe
list 2 types of AI syringes
- O-ring
- Spiral
what temperature should the semen thaw bath be (give celsius and farenheit)
35-37 C
100-101 F
how long should semen be in the thaw bath?
30-60 seconds
what is the reason for using straw forceps when grabbing a semen straw?
to prevent hurting other straws not in use
why is it important to get the semen into the cow no later than 10-15 minutes after thawing?
sperm start to die as soon as thawed
why is it important to point the syrunge dorsally when entering the repro tract?
to avoid hitting the urethra or suburethral diverticulum
what is another name for the fornix?
blind pouch
what is the start of the cervix called?
external os
why does the poke and hope method not work for AI?
the fornix will get ya every time
how do you move the syringe through the cervix?
manipulate the CERVIX over the syringe
what are the two possible places for semen deposition?
uterine body or cornual insemination (uterine horns)
list the 5 steps/locations in the major sequence of events following deposition of spermatozoa in the female tract
- immediate transport
- cervix
- uterus
- oviduct
- fertilization
what happens in the first step/location in the major sequence of events following deposition of spermatozoa in the female tract?
in immediate transport:
- retrograde loss of semen
- phagocytosis
- entrance into cervix/uterus
what happens in the 2nd step/location in the major sequence of events following deposition of spermatozoa in the female tract?
in the cervix:
- “priveleged pathways”
- removal of non-motile sperm
- removal of some abnormalities
what happens in the 3rd step/location in the major sequence of events following deposition of spermatozoa in the female tract?
in the uterus:
- capacitation initiated
- phagocytosis
what happens in the 4th step/location in the major sequence of events following deposition of spermatozoa in the female tract?
in the oviduct:
- capacitation completed
- hyperactive motility
what happens in the 5th and final step/location in the major sequence of events following deposition of spermatozoa in the female tract?
fertilization:
- acrosome reaction
- spermatozoon penetrates oocyte
- male and female pronuclei form
what is the bovine retrograde loss of sperm with natural service?
greater than 80%
what is the bovine retrograde loss of sperm with AI?
30-60%
how many sperm are initially released in a natural service? retrograde loss?
10,000,000,000, with 80% loss
how many sperm are initially released in AI? retrograde loss?
less than 30,000,000, with 30-60% loss
when do you breed when using AI?
12 hours after first observation of estrus
why don’t you breed duirng estrus?
to avoid peak mucus production, resulting in less loss of sperm
where DONT you deposit semen in AI?
the vagina
give the percentage of sperm loss when AI deposit in: uterine body, uterine horns, and cervix
uterine body: less than 20%
uterine horns: less than 20%
cervix: greater than 60%
why don’t you just deposit in the uterine body?
many inseminators are not actually that accurate in knowing when they are in the uterine body
what is the advantage of depositing in the uterine horns?
the uterine horns are easier to feel, which eliminates accidentally depositing in the cervix
what is the rule for depositing in the uterine horns?
slide until you meet resistance, deposit half, come back, tilt, deposit other half
