We’ve talked about making baby calves in The Business of Making Baby Cows:
We have talked about how we take care of our baby calves in All Those Adorable Babies:
But how do we know that a cow is pregnant? They can’t talk obviously, they don’t pee 10 times on a stick and post it to their Facebook page (a little TMI in my opinion) and they don’t show signs of morning sickness. It is our job as farmers to do a little investigating to find out.
On our farm we check for pregnancy the first time at 28-34 days after insemination. We use a simple blood test called Bio-Pryn. It measures protein levels in the blood. Cows have a small vein that runs up the underside of their tail. The tail is simply picked straight up, a hypodermic needle is inserted in to the vein and the blood is collected in a blood collection tube. We draw blood every Monday and send it via the US Postal service to a vet clinic in Pennsylvania. There it is processed with the results popping in to my inbox by 10am on Thursday morning. And who says farmers aren’t tech savvy?
Below is a sample of what the report looks like that is sent to my e-mail. The top has the date, specie and number of samples. The next line has the parameters used to decide if the cow is pregnant (yea!), open (no calf inside, boo!) or needs to have blood drawn at a later date for a re-check (this is normally boo, as it more often than not results in an open cow). This is then followed by a chart that has the sample number, animal ID number, their response level, if they were pregnant, open or a re-check and the last column has the number of days since they were bred on the day the sample was taken.
|Report Date||Assay/Animal||Number of Samples|
|03/06/2014||Cattle – 11 samples||11|
|Open||Low Recheck||Cutoff||High Recheck||Pregnant|
|OD < 0.135||OD = 0.135 to 0.15||0.15||OD = 0.15 to 0.21||OD > 0.21|
|Tube Number||Animal ID||Response in Test, OD||PSPB Range||Days Post Breeding|
|BioPRYN measures the presence of Pregnancy-Specific Protein B (PSPB) in serum and the attached results are provided for your interpretation. If a sample’s OD falls in the Open range, 99.9% of animals are not pregnant in confirmatory testing; alternatively, if the OD falls in the Pregnant range, 93 – 95% of animals are pregnant in confirmatory testing. Visit the website listed on this report for more detailed information about the BioPRYN test.|
|© Biotracking LLC 2004-2009 All rights reserved.|
After a cow comes back pregnant to the first test she is then re-sampled at 60 days post insemination. This checks for miscarriages. Cows can miscarriage, or “slip a calf”, for a variety of reasons. Illness, heat stress, injury, general stress and spontaneously just to name a few. Most miscarriages happen around 35-45 days, hence re-checking at 60 days. After she comes back pregnant to the second test, we consider her verified pregnant and she is done being tested. Some farms re-test before sending their cows on their dry period. We haven’t had much problem with cows going unnoticed losing a calf later in pregnancy so we do not on our farm.
This is not the only way to check for pregnancy. This is just what we do. Here are some others:
Palpation: A cows uterus can be felt via her rectum. A vet, or trained person, can palpate a cows uterus to determine pregnancy. A lot can be discovered this way. If she is indeed pregnant, how far along she is or if there is on calf or multiples. On our farm we will palpate cows if we believe they have slipped their calf later in pregnancy or if she is showing signs of heat when she is supposed to be pregnant. While I’m sure this is not 100% comfortable for the cow, it does not hurt her.
Ultrasound: Just like humans, cows can have an ultrasound done to determine pregnancy. This is normally done by a vet but more and more farmers are becoming comfortable with this technology. Just as in palpation stage of gestation and number of fetuses can also be determined. The neat thing about ultrasound is after 60 days, the sex of the fetus can be found out. No more waiting anxiously, you know what’s coming. The down side is this can also lead to 7 months of depression if a bull is coming from your favorite lady.
Milk Sample: Pregnancy can also be determined thru a milk sample. This is then processed at a DHI (dairy herd improvement) lab. It tests for the same proteins as the Bio-Pryn blood test, but you do not have to go thru the work of drawing blood. Instead it is done from the sample that is already routinely taken when the milk tester is there.
There are many ways a farmer can determine if a cow is pregnant. This is essential so she has a calf and will continue to produce milk. While she may not show us signs of morning sickness we have plenty of ways to see if the next generation of bovines is on the way!