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