Equine - Breeding Management Flashcards
How often is transrectal palpation and ultrasonography perfermed as a mare cones into estrus and develops a dominant follicle?
every other day to every day
What additional diagnostics can be done to assess estrus behavior in a mare?
teasing and vaginal speculum (to examine for cervical relaxation)
What history do you need to gather for breeding management?
age and reproductive status, method of insemination, breeding history, and any other significant history
A thorough physical examination needs to be done for breeding management including examining what?
perineal confirmation and mammary glands
How quick after foaling will mares come into estrus and what is that called?
foal heat - 6-10 days following foaling
What is the criteria to be bred on a foal heat?
there needed to be a normal foaling, normal uterine involution (no to minimal fluid), and only if ovulation occurs after day 10 post foaling
If the criteria is not met to breed at foal heat, when can they be bred?
the next natural cycle or short cycle with prostaglandin
What is good perineal confirmation?
it is 2/3 below the pelvic brim, there is vertical orientation, and good lip apposition
If a mare doesn’t have good perineal confirmation, what can be done?
A temporary or permanent Caslick’s following breeding and/or pregnancy confirmation
What tests can be done to evaluate perineal confirmation?
Windsuck test and a Caslick’s index
How do you perform a ‘Windsuck’ test?
Part the vulvar lips and note for rapid aspiration of air - a mare shouldn’t aspirate air
How is the Caslick’s Index calculated?
the length of the vulva (cm) x the angle of the vulva (deg)
What is a normal Caslick’s Index result?
less than 100
What are the different reproductive diagnositc modalities?
transrectal palpation, transrectal ultrasonography, vaginal speculum examination, and hormonal profiling
What does transrectal palpation assess?
cervical tone, follicular size, and follicular character
What does transrectal ultrasonography assess?
follicular dynamics, presence or absence of uterine edema, and any abnormalities
What does vaginal speculum examination assess?
the equine cervix
When would hormonal profiling be performed?
in mares with abnormal cycles
What injury is a risk of any palpation and/or ultrasound procedure in horses?
rectal tear and/or irritation
What can be used to mitigate risks of a rectal tear and/or irritation?
restraint, sedation, lube, and technique/patience
If any blood is noticed on your sleeve during or after palpation/ultrasound, what should be done?
It should be immediately evaluated by bare arm palpation to determine the source within the rectum and potential severity or grade
What is a grade 1 cervical score?
The cervix is 1-finger width, in diestrus and ideal pregnancy score
What is a grade 2 cervical score?
The cervix is 2-finger width, in diestrus or early estrus, non-ideal pregnancy
What is a grade 3 cervical score?
The cervix is 3-finger widths, in estrus
What are the key points in a rectal palpation?
Tract should not be reflected, palpate the entire reproductive tract, confirmation of ovaries, and palpate all of the palpable structures
What structure is not palpable in the mare?
CLs
What is the general path to identifying things in a transrectal ultrasound?
ID the urinary bladder and uterine body. Follow the uterine body to the bifurcation to the uterine horn and then to the ovary. Repeat on the other side
What should be evaluated during transrectal ultrasound?
Evaluate the ovarian structures, uterine edema, uterine fluid, other abnormalities, and the presence/absence of pregnancy
What is grade 0 uterine edema?
no edema
What is grade 1 uterine edema?
mild edema - beginning of wagon wheel on ultrasound
What is grade 2 uterine edema?
moderate edema; folds are equivalent
What is grade 3 uterine edema?
heavy edema
What is grade 4 uterine edema?
pathologic edema, frequently found surrouding fluid
What is uterine fluid graded based on?
volume - measure the diameter and location
When are artifical lightening programs used?
to bring mares into heat prior than when they would cycle naturally
How long does it take for a mare to respond to artifical lighting programs?
6-8 weeks (60 day average)
When would artifical lighting typically begin?
Mid December to guarantee cyclicity in February or March of the next season
What duration of light is needed for manipulation of the estrous cycle?
16 hours
How is a 16 hour duration achieved in the winter?
light is added at the end of the day (after sunset) - it must not be a constant light
Aside from adding lights around the entirety of the stall, what else can be used as an artifical light?
Equilume masks which shine light frequency into the retina via the mask
What hormone can shorten diestrus?
progesterone
What exogenous prostaglandins can be used for estrous cycle management?
Dinoprost (Lutalyse) or Cloprostenol (Estrumate)
What is the standard protocol for exogenous prostaglandin and why?
Administer 5 to 6 days following ovulation because you must have a mature CL to respond to prostaglandin
What drugs can induce ovulation?
human chronic gonadotropin and deslorelin acetate (GnRH)
When does ovulation occur after giving HCG?
ovulation occurs in approximately 36 hours (24-48 hr range)
What follicle size should there be if you plan on giving HCG?
greater than 35mm
Why should you limit the use of HCG to 1-2/season?
because there is a potential for antibody formation
When does ovulation occur after using Deslorelin acetate?
In approximately 44 hours (40-48hr range)
What are the ‘requirements’ to using Deslorelin acetate?
greater than 35mm follicle and signs of estrus
What are the different breeding methods that could be used?
pasture breeding, hand breeding, and artificial insemination
What are the different types of artificial insemination (locations)?
intrauterine (fresh, cooled, or frozen semen) and deep horn (frozen semen)
What is live cover breeding?
In hand or pasture breeding where ejaculate is deposited directly within the uterus
For what group of horses is live cover required?
for thoroughbreds to be registered with the Jockey Club
What is the window for breeding with fresh or shipped cooled semen?
breed within 48 hours of expected ovulation
How long are fresh or shipped cool semen typically viable?
on average of 48 hours depending on stallion fertility
What are the requirements for semen for AI?
Minimum of 500 million progressively motile sperm - >60-70% motility and >70% normal morphology
What is the average pregnancy rate for AI with fresh or shipped/cool semen?
60-80%
What is the window for breeding with frozen semen?
the goal is to deposit semen within 12 hours prior to ovulation to 6 hours following ovulation
How long do frozen sperm typically live? The oocyte?
frozen sperm - 12 hours; oocyte - 6-8 hours post ovulation
What is the single dose protocol for frozen semen?
Check for ovulation every 6 hours and breed post confirmed ovulation
What is the strictly time AI protocol?
- Administer hCG
2. Breed at 24 hours and 40 hours post administration - hoping ovulation occurs during the buffer
What are the downfalls to a strictly timed AI protocol?
Potentially allows for elimination of multiple checks and less exact monitoring and timing of the oocyte
What is ISUs recommendation for progressively motile sperm numbers in frozen semen?
minimum of 400 million progressively motile sperm
What is the average pregnancy rate when using frozen semen?
approximately 35%
What happens in a post breeding examination?
confirm ovulation and examine for and manage any post breeding intrauterine fluid
What can be used to get rid of any post breeding intrauterine fluid?
Oxytocin-ecbolic agent to cause uterine contractions and clearance or Prostaglandin +/- intrauterine lavage
When would temporary Caslick’s with stainless steel staples be placed?
until pregnancy examination, embryo flush, etc.
When would a permanent Caslick’s be placed?
following pregancy confirmation
