In which anatomical site does artificial insemination most commonly occur in cows?
Intra-uterine horn (frozen is most common)
In which anatomical site does artificial insemination most commonly occur in pigs?
Transcervical (fresh or cooled is most common)
In which anatomical site does artificial insemination most commonly occur in small ruminants?
- Vaginal (fresh)
- Cervical (fresh)
- Uterine (frozen)
In which anatomical site does artificial insemination most commonly occur in dogs?
Vaginal (fresh or cooled is most common)
Where are two types of artificial insemination used in horses?
- Normal AI (intouterine body)
- Low dose insemination (deep-horninsemination (close to utero-tubal junction) or hysteroscopic insemination)
Low dose AI technique is not an effective strategy in studs and mares with which conditions?
Not effective for sub-fertile/infertile studs or mares with reproductive problems
What is the main risk of AI in horses?
PBIE (post-breeding induced endometritis) (inflammatory reaction of the uterus to sperm)
Why is low dose considered a better option than normal AI in a healthy mare?
There is less risk of a uterine inflammatory reaction with a low dose insemination
How do you know when to breed a dog?
Measure progesterone until levels reach a certain point, then perform AI or have a stud dog come
What is the difference between dogs and all other species regarding their ovulation?
Dogs ovulate aprimary oocyte(an immature oocyte that needs to mature during transport in oviduct - this is fine in dogs because their reproductive tract is extremely long)
Should dogs be bred before or after ovulation?
Afterbecause we need time for the primary oocyte to mature before we attempt fertilization or it will fail (all other species are bred before ovulation)
Ex. progesterone levels are around 5 ng/mL at time of ovulation but we wait until they are around 17-24 ng/mL before we breed (which can be 3-4 days after ovulation)
What is the difference between the sperm in the epididymis and in the semen?
The sperm in the epididymus are not mature
What is an advantage of using sperm from an epidydimal sperm collection?
The sperm in the epididymis are immature, so they might handling the cooling or freezing process better
When are two instances you might do an epididymal sperm collection?
In a high value animal you are:
- Castrating(may as well use his sperm with it)
- Euthanizing/sudden death(will work up to 24 hours after death)
Describe the process of epidydimal sperm collection (six steps)
- Collect the epididymis within 24 hours after death or castration
- Rinse with cold sterile saline and transport under chilled conditions (to slow metabolism)
- Dissect the epididymis
- Perform retrograde flush technique (most common technique in horses)
- Perform float up technique (used in dogs)
- Centrifuge solution to remove debris
- Cryopreserve sperm with an appropriate protocol for the respective species
In which two species is epidydimal sperm collection most common in?
Dogs and horses (but can occur in any species)
True or False: There is a large variation in how some males freeze over others
TRUE
What are the two main cryopreservation procedures used forspermfreezing?
- Dry ice (- 79 °C)
- Nitrogen vapor (- 100 °C)
What is the sex-sorted sperm process?
- Stain all DNA with a fluorescent dye
- X chromosome has a higher amount of DNA (it’s bigger than Y) so it stains a bit brighter
- A machine laser detects dye
- flourescence is measured and a +ve or negative charge is applied to each drop
- sorted based on the amount of DNA it has (sorting options are X, Y, or trash based on positive or negative charge)
- Anything it can’t recognize easily is put into trash, so this eliminates any poor quality DNA
- This leads to a 90% purity rate (10% chance of wrong sex)
What are four advantages of the sex-sorted sperm process in cattle?
- Most sustainableproduction system
- Decreases calf wastage
- Gives more opportunities for “beef on dairy” (we want more male beef cattle to cross with dairy cows)
- Breeds genetically superior animals for replacement (as machine trashes any weird looking DNA)
What are four disadvantages of the sex-sorted sperm process in cattle?
Remember TIME and TRASH
Time:
- Takes 3 hours to sort one ejaculate
- Delays AI by 6-18 hours (because semen can’t survive until they undergo capacitation)
Trash:
- 75% of sperm are discarded (damages some cells so has shorter capacitation)
- Reduces pregnancy and calving rates by 20%(versus regular semen)
What is embryo transfer? What are the two types of embryo transfer?
Embryo transfer is the process of collecting embryos from a donor female and transferring them to recipient females for gestation. There are two types, based on how you select the embryos used for transfer:
1. In-vivoderived (IVD)
2. In-vitroproduced (IVP)
What are four advantages of using embryo transfer?
- Can be used for preservation and propagation of endangered species
- Bypasses maternal blocks (anovulation, repeat breeders, or early embryo mortality)
- Increases the number of offspring from valuable females
- Allows production of offspring from infertile or even deceased animals
What is IVD?
A type of embryo transfer in which embryos are collected from a donor female that has beensuper-ovulatedusing FSH (in-vivo derived)
(rescuing follicles that would otherwise die)
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Review45
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Dairy 152
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Dairy 234
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Dairy 368
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Beef Cow Repro42
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Dystocia53
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Repro Tech43
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Bull BSE69
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Male Pathophysiology (ew)97
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Small Ruminants41
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Pig Theriogenology73
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Small Animal 169
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Small Animal 293
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Small Animal 359
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Equine 162
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Equine 243
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Equine Lecture 2 - Pathologies33
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Equine 398
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Equine 4150
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Prolapses46
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