Reproductive Efficiency

Reproductive Efficiency Determining Pregnancy Status Karla Blackstock

Reproductive efficiency has a significant economic impact on any livestock producer, and Boer goat producers are not immune.

Accurate, cost-effective and convenient detection of pregnancy status allows producers to better evaluate conception rates and effectiveness of an AI/ET program. Open females can be rebred quicker to avoid losing time without kids on the ground. Pregnancy testing is an invaluable management tool by shortening kidding intervals as early as 30 days after breeding by confirming pregnancies.

Technology advancements allow producers to detect pregnancies as early as 30-days bred; however, there are other alternatives that may be less invasive and/or offer a better view of the pregnancy.

Blood tests remain the quickest detection method. Urine tests allow producers who do not have the ability to collect blood to test for bred females during the second and third trimester of gestation. And, ultrasound allows producers the ability to identify singles, twins, triplets and even quadruplets.

Willy Tate, co-owner of BioTracking, Inc. said that blood tests are safe and effective at just 30 days post breeding by using proteins found in the blood.

“Whether AI or buck bred, immediately following conception, the doe begins to produce placental protein (PSPB) that can be measured in her bloodstream at definitive levels as early as 30 days post breeding or exposure to a buck.” Tate said. “This protein is only elevated when the animal is producing a placenta and the absence of this protein is a 99.9% indicator that the animal is open. As long as the blood sample is drawn 30 days post breeding or greater.”

Obtaining blood for pregnancy testing does require producers to shave a portion of the doe’s neck to draw at least 2 cc’s of blood. The blood draw can be done on the farm/ranch and shipped to a local BioPRYN lab.

Tate said that the placental protein is fairly stable; therefore, refrigeration during shipment is not necessary. In fact, he said, “BioPRYN has a growing number of Affiliate Labs that offer BioPRYN that can provide local support and quick turnaround.”

The BioTracking website provides step-by-step instructions, including a video as well as shipping instructions for each major carrier (USPS, UPS, FedEX).

However, if you are not interested in drawing blood and are looking for a way to test for pregnancy on the farm/ ranch, EM Lab Genetics has another solution. EM Lab’s P-TEST is a simple test that takes about an hour to complete.

By testing estrone sulfate in bodily fluids (urine) using a simple colorimetric reaction, pregnancy can be monitored in the 2nd and 3rd trimesters after breeding without palpation or ultrasound. The urine test is effective at 50 days post breeding.

According to Dr. Timothy Willams of EmLab Genetics, “Estrone sulfate has been used for pregnancy testing for thousands of years.” “The test is unique in that the hormone being tested is directly related to the fetal health,” Williams said. “As the fetus grows, the hormone increases.”

This allow the test to provide producers with a basic idea of the length to parturition.

A simple color chart is enclosed in each test, allowing producers to quickly identify stages of pregnancy.

Color Time (Minutes) Yellow-Amber 1

Blue

Blue-Green

Green Light Green 10 Result

Not Pregnant Pregnant - Late term Pregnant-Mid term Pregnant - Early term Pregnant - Very early term

However, Williams, said if the fetus is aborted it will take a few weeks for the hormone to return to normal per-pregnancy levels. During this time-frame, the test can give producers a false positive.

“The major advantage of the P-TEST is that you can actually monitor a pregnancy,” Williams said. “If it looks like there is a loss, you can re-run the test at any time.”

The test will not, however, tell you if a doe has lost one out of multiples. Therefore, it is not a way to determine overall health of a doe during late pregnancy stages.

Detailed instructions are included in the P-Test kit, and Williams stressed the importance of collecting fresh, clean urine.

“The composition of the urine drives the test so the quality is important,” he said.

In other words, he said, using a cup to collect the urine rather than sponging urine off the concrete floor is the best method.

In addition, producers are instructed to cool the urine to room temperature.

“If the urine isn’t cooled, you might come up with a false negative because the test will run too quickly,” Williams said. “But on the other hand, cold urine isn’t ideal so we tell people to err on the side of running the test with urine that is a little warm.”

Neither the P-TEST nor the BioTracking blood test can detect multiples or specific physical/anatomical reasons as to why an animal may be open.

In order to detect multiples, producers still rely on ultrasonography. A transabdominal ultrasound is a quick and reliable way to detect pregnancy as early as 25 days, with the fetal heartbeat detectable by day 27.

Skilled ultrasound technicians may be able to differentiate between twins, triplets, and quadruplets using ultrasound at any time during gestation. Fetal sexing may be performed by skilled technicians between days 55 and 70 of gestation and is more accurate in singles versus multiples.

Routine radiography can be used to detect pregnancy with 100% accuracy after day 70 and can detect the number of kids after day 75.

Whether using blood tests, urine tests, ultrasound tests of the old wives’ tale of holding a nail over the doe’s head, it is important for producers to determine the pregnancy status of does in a herd in order to cull for sub-fertile females. By keeping only reproductively sound females, producers can increase overall value and return on the investment.