ReproScan ultrasound equipment provides solutions for all the challenges that may be found with
dairy cattle reproductive ultrasound. When selecting ultrasound equipment for
dairy cattle reproductive examinations, one needs to consider many factors.
Early Pregnancy Diagnosis
A presumptive diagnosis of pregnancy can be made as early as 26 days. This
diagnosis is based on the presence of clear uterine fluid and a functional
corpus luteum (CL) greater than 20 mm on the same side as the fluid. These
pregnancies must be rechecked as the rate of pregnancy loss at this stage can
be quite high. Very early pregnancy scanning is usually done with a handheld 6.5
MHz linear rectal probe which can be found in our Apexx, Flexx, XT, and BoviScan product lines
(6.5 MHz probe). Pregnancy testing at 30 days and up gets considerably easier to
perform. The heartbeat in the embryo can be used to confirm the viability of the
pregnancy. The 4.0 MHz convex rectal probe can be used for early pregnancy
exams with the “arm in cow” method. The larger field of view makes some
examinations easier but there is a slightly lower resolution with the larger
scanning area. Extension arm ultrasound usually starts at 35 days and up in
moderate sized, seasonally bred dairy cattle.
Examination of Ovarian Structures
Ovarian examinations are usually done with a 6.5 to 7.5 MHz linear rectal probe
such as the Apexx Linear, BoviScan HD, BoviScan Linear or ReproScan Flexx (6.5 MHz probe).
The presence or absence of a functional corpus luteum is often used to
determine which estrus synchronization program will best suit an individual
cow. Some veterinarians prefer a C20 micro convex probe on their BoviScan or
ReproScan Flexx unit. Please contact your ReproScan representative to discuss
which ReproScan or BoviScan unit is right for your dairy practice.
Fetal Aging Pregnancies less than 120 days (17 weeks)
Fetal aging in early pregnancies is done by measuring the fetus with the 1 cm
grid or 2 cm grid. Fetal aging charts are available. Crown rump length and head
diameter are the most commonly used measurements.
Fetal Aging Pregnancies over 120 days (over 17 weeks or 4 months)
Fetal aging dairy cattle in advanced stages of pregnancy is more difficult and
less accurate than earlier in gestation. The 4.0 MHz convex rectal probe with
its larger field of view is better for later term examinations and dry off
checks.
Fetal Gender Determination (Fetal Sexing)
Fetal sexing is usually done by “arm in cow” method from 58 to 80 days with a
6.5 MHz linear rectal probe such as on the Apexx Linear, BoviScan HD, BoviScan Linear or
ReproScan Flexx. Fetal sexing can be done with the 4.0 MHz convex rectal probe
with or without the extension arm. Depending on the size of dairy cattle,
sexing fetuses from 70 to 90 days often works out better when using the 4.0 MHz
convex rectal probe.
Pregnancy Testing in Seasonal Dairies
Seasonal dairy cows are often smaller framed and easier to pregnancy test. The
4.0 MHz ReproScan Apexx Curve, XTC and the BoviScan Curve do an excellent job of pregnancy
testing seasonal dairy cattle. This type of pregnancy testing is similar to
cow-calf pregnancy testing. The ReproArm extension arm is used to increase
speed and reduce fatigue and injuries to the veterinarian. Fetuses are often
aged in 5 day increments from 35 to 100 days.
Seasonal dairying is a large industry in New Zealand and extension arm
ultrasound is used by 100% of veterinarians and technicians that provide
pregnancy testing services to these dairies.