Pregnancy Detection Flashcards
Why Detect Pregnancy?
- Palpation of the reproductive tract (trans-rectal or abdominal)
- Imaging of the reproductive tract (radiograph or ultrasound)
- Measurement of hormone concentrations (blood or other fluids)
Bovine Pregnancy Detection
Beef Cattle Herds
a Controlled breeding season - 60-90 days
A herd Assessment:
Goal: get a lot of cows pregnant and a lot of cows pregnant in the first 20 days of breeding
Determine success of proceeding breeding season
Provide diagnostic information
Identify open cows for alternate management
Bovine Pregnancy Detection
Dairy Cattle Herds
Some dairies are seasonal - controlled 60-90 day breeding season similar to beef herds
Most dairies breed year-round
results in steady milk supply
Mostly an individual cow assessment
Determine dry-off date
Determine if cow should continue in breeding pool
assess herd breeding program
Types of Pregnancy Tests - Bovine
- Milk of blood progesterone assay
Milk progesterone values correlate with bood values
Remember the fluctuation of progesterone concentrations over an estrous cycle
Must know breeding date - and test at specific time after that breeding date
If progesterone is found to be low = not pregnant
If progesterone is found to be high = pregnant or in diestrus
Types of Pregnancy Test - Bovine
- PSPB - Pregnancy Specific Protien B
Can be detected as early as 25 days of gestation
Remians in blood for up to 3 months after parturition
How would you interpret a postive test on a cow with a calf-at-side 35 days after the start of the breeding season?
-False positve due to having calved less than 3 months ago
How would you interpret a positive test on a heifer 35 days after the start of the breeding season?
-True positve
Types of Pregnancy Tests - Bovine
- Early Conception Factor
Can be detected as early as 6 days of gestation
Although promoted by advertisements and anecdotal testimonials
Results of studies have shown unacceptable accuracy
Types of Pregnancy Tests - Bovine
- Detection of estrus
Why not just detect estrus and assume that cows not detected in estrus are pregnant?
becuase cows are polyesturs - takes lots of really well trained humans to watch the cows
Types of Pregnancy Tests - Bovine
Ultrasonography
Routinely accurate at 28 days gestation
Can determine sex of fetus between 55-65 days gestation
Very difficult as fetus grows and uterus pulled over pelvis
Types of Pregnancy Tests - Bovine
- Uterine palpation per rectum
Routinely accurate by 35 days gestation
Fast and accurate with experience
Less information than ultrasound
Ovarian structures, fetal sex, fetal viability
Uterine Palpation per Rectum
Landmarks
Pelvis - Bony
Cervix - Hard
Uterus is right in front of cervix - if you get lost - go back to cervix
Uterine Palpation - Age determination
Simpy determining if a female is pregnant or not is not high-quality veterinary practice
The whole reason to do a post-breeding season reproductive examination is to estimate the age of the fetus
and Use that information to evaluate the breeding program and dx. problems
Uterine Palpation - age determination
range in gestation
He is most comfortable determining fetal age from 35-100 days of gestation
For a herd with a desired 60 day calving season - can palpate the herd 95-100 days after the start of the breeding season
Leave bull in pasture until pregnancy check
If poor pregnancy success - leave bull in longer
Determine Age of Gestation:
Fluid Volume
40 days - 75ml
60 days - 300ml
90 days - 1,000ml
120 days - 3,000ml
Determine age of gestation
35 days
slight amount of fluid in uterus
able to “slip” fetal membranes
Determine Age fo Gestation
40 days
Slightly more fluid than 35 days
uterine wall is thinning
Determine Age of Gestation
60 days
Pregnant horn is size of banana
still able to hold entire tract in your hand
Determine Age of Gestation
90 days
can still reach around entire tract - but barely
Routinely “bump” the calf
Routinely feel placentomes
Determine Age of Gestation
120 days
cannot reach around entire tract
Placentomes are promient - nickel - sized
Fremitus in mid-uterine artery on pregnant side
Confusing Structures for Uterine Palpation
Bladder
Back of Rumen
Left Kidney
Gass Bubble in intestine
Pyometra
Lymphoma
Uterine involution (post calving)
Use of Ultrasound
Used in many practices
Much better than palpation for examination of ovaries
Still a “snap-shot”
Cannot determine if sturcture is getting bigger or smaller
Use of Ultrasound
Pregnancy Diagnosis
A little earlier preg diagnosis: 28 days vs. 35 days
Able to assess fetal viability
Able to determine sex
Little slower than palpation
“Wow” factor
Use of Ultrasound
sex determination
Gentital tubercle is in noticeably different position by about 55 days of gestation
Located immediately caudal to umbilicus in male
Much past 70 days - difficult to consistently get right area of fetus on the screen
Use of Ultrasound
Embryo Transfer
Identify recipients of CL
Follow follicular dynamics of donor cow - count CLs at flushing
Equine Pregnancy Detection
Equine Chorionic Gonadotropin (eCG)
At 36-38 days of gestation, fetal chorionic tissue invades the endometrium and forms Endometrial cups- these cups secrete eCG
eCG acts to luteinize the normal follicular waves that are occurring and results in the formation of secondary CLs
eCG levels peak about day 60-80 of gestation
eCG assays will detect a high percentage of pregnancies by day 42
eCG remains elevated if the pregnancy is lost - therefore a non-pregnant mare can have high serum eCG values
Equine Pregnancy Detection
Estrogens
The Cuboni test
Fluorescence of urine due to estrogen
Will accurately detect pregnancy by 100-150 days of gestation (pregnancy is also easily palpated per rectum by this time)
Equine Pregnancy Detection
Estrone Sulfate
Present in serum, urine and even feces of the pregnant mare
Because non-invasive samples can be used - this test is utilized for assessing wild equine reproduciton
After day 44 of gestation, high estrone sulfate is associated with fetal viability
Equine Pregnancy Detection
Early Pregnancy Factor (EPF)
Immunosuppressive protein secreted by the early embryo
Detected as early as 24-72 hours afte rmating and remains elevated through the second trimester of gestaiton
Poor test accuracy (43% sensitive / 52% specific)
Equine Pregnancy Detection
Cervical Tone and Appearance
Progesterone form CLs peak at day 80-90 of gestation
High evels of progesterone cause the cervix and uterus to have exaggerated tone
Equine Pregnancy Detection
Uterine Palpation per rectum and trans rectal ultrasound
Chorionic vesicle is distinctly spherical
Vesicle is palpable form day 18 to day 60-70
Vesicle is visible via ultrasound beginning about day 10 of pregnancy
Equine Pregnancy Detection
Use of Ultrasound for fetal Sexing
Genital tubercle migrates toward the umbilicus in the male and the anus in the female
Fetal sex is determined form day 59-68 of gestation
Canine Pregnancy Detection
Abdominal Palpation
Start at the dorsal abdomen and move your hand downward and squeeze thumb and fingers together gently - slip the uterus between the thumb and fingers
Day 21-31, the pregnancy can be palpated as small, firm, round vesicles
Fetus count not possible
Determining fetal viability is not possible
Palpation may be difficult in large dogs, dogs that tense, and dogs with a log of mammary development
day 31-50 vesicles loose their distinct round shape and are not palpable
after day 50 puppies are palpable
Canine Pregnancy Detection
Trans-abdominal ultrasound
Fetal vesicles are visible by day 18-20 past the LH peak as distinct, round, black sacs
Fetal heartbeat and fetal movement are indication of fetal viability
Ultrasound ismore accurate than palpation
It is difficult to count fetuses
Canine Pregnancy Detection
Radiographs
Fetal skeletons first seen 42-52 days after breeding - 44 to 47 days after LH peak
After day 50 fetal skeletons can be counted
Canine Pregnancy Detection
Relaxin - measured from blood sample
Detected by day 20-30 past LH peak
Commercial kit is avialable
Porcine Pregnancy Detection
Detection of return to estrus
Non-pregnancy sows should return to esturs 17-24 days after breeding
Sows behavior should be evaluated in the presence of a boar
False positive results are common (falsely identify a female as bred when she is not)
Porcine Pregnancy Detection
A-mode ultrasound
use US waves to detect fluid-filled uterus
Output: audible signal or a series of lights
High accuracy at 30-75 days
The number of false-negatives resutls increases after day 75
Porcine Pregnancy Detection
Doppler Ultrasound
Detects movement such as fetal heart and pulsing umbilical / uterine arteries
Output is an audible signal
High accuracy after 30-34 days
Risk of false-postive during proestrus or estrus
Porcine Pregnancy detection
Real time ultrasound
expensive - so not used on small farms
Able to detect pregnancy sooner thatn with A-mode or doppler
The better the reproductive performance of a farm, the less advantages of using real-time US
Ovine Pregnancy Detection
Real-time Ultrasound
Can detect pregnancy as assess fetal numbers as early as day 25 of gestation
Ovine Pregnancy Detection
Pregnancy - specific Protein B
Can be detected as early as day 20 of gestation
