How to Tell if a Cow or Heifer Is Pregnant
Observe the behaviour of cows and heifers., Pay attention to physical changes of cows and heifers., Fetal responsiveness to physical or observational pregnancy testing., Perform an accurate scientific pregnancy diagnosis to confirm observations.
Step-by-Step Guide
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Step 1: Observe the behaviour of cows and heifers.
The behaviour of cows and heifers after they have conceived is one of the best non-invasive means of determining pregnancy in cattle.
Simply put, pregnant cattle will not (or should not) come into estrus or "heat" for the entire duration of the
9.34-month (285 day) gestation period.
The estrous cycle in cattle occurs, on average, every 21 days.
If a cow or heifer has aborted or absorbed the embryo, she will soon come into estrus and continue regular cycling until she conceives again.
Embryo absorption, early embryonic death, or fetal abortion can happen at any time during a cow's pregnancy and can be caused by anything, from extreme stress to a disease a cow acquired before or during her gestation.
How to Tell when a Cow or Heifer Is in Estrus fully explains the estrus activity shown by such cows.
Thus if a cow unexpectedly starts to behave like she's in estrus during her pregnancy, particularly if she is several months along, chances are she aborted the fetus and is beginning to get back into regular cycling.
Absorption of the embryo occurs within the first two to three weeks after breeding.
False heats may be experienced by females during the first few weeks post-conception, and though they are rare, they can be easily misdiagnosed by the producer as an actual heat period.
Such suspicions can only be confirmed or rejected if follow-up with a proper test (see below) is completed at least a month and a half after breeding.
Observing behaviour also applies to cows' and heifers' male counterparts.
Bulls will not show any interest to any cows that maintain pregnancy.
They only show interest if a cow comes into heat and when she's ready to calve.
This is because, during both periods, estrogen levels increase every time a cow is one to three days away from coming into heat, and when it's time for the calf to be born. (At birth, the fetus sends stress signals to the dam's nervous system which starts a cascade of hormonal events, such which largely includes progesterone levels decreasing and estrogen increasing.) A bull can sense this through performing what's known as the "flehmen response" where he "tests," via drinking, the urine of a female to check for pheromone activity.
The bull tilts his head up high and back as far as he can to allow the fluid to drain into a sensory organ in his nasal passage called the Jacobson organ.
Curling his upper lip up allows the urine to flow into this organ as deep as possible to better test for pheromone activity.
High levels of progesterone in the cow's system, which would be present in the urine, will tell a bull that she is not available for his services.
Besides getting a little bit of a head-butt to the ribs from the cow herself in displaying her disappointment in his flirtatious advances, it also tells him that it's probably best to find another female that would potentially be in more need of his amorous intentions. -
Step 2: Pay attention to physical changes of cows and heifers.
Changes to size and shape of body parts can be noticed in both cows and heifers, primarily with the abdomen (or "barrel"), and the udder.
Unlike humans, cows do not typically show their "baby bump" until they're about half-way through gestation.
Only after then do you begin to see how the cow or heifer is getting larger in the abdominal region.
By mid- to late-third trimester when a cow or heifer is considered "heavily pregnant," she synonymously looks quite like a large, round barrel with a head, a tail, and four legs.
In heifers, the udder begins to fill out more and reach maturity.
Heifers that are "virgin" or not yet conceived will have an under-developed udder that is only resembled by the presence of four small teats tucked up under their belly between their hind legs.
As they progress into their gestation period, the udder gradually becomes more prominent until she gives birth.
A heifer will not have as defined an udder as a mature cow will (nor even a mature dairy cow), but it will be as big an udder as a heifer will need to feed her newborn calf.
Mature cows already have a fully developed udder so there will be no change in the physical structure of the mammary organ as in the bred heifers.
Cows also will not begin to fill up with milk until they are showing signs that calving is imminent.
However, a cow that is pregnant and still has a calf to suckle will continue to produce milk until that calf is weaned.
With dairy cows, when they successfully conceive and become pregnant they will continue to lactate until they are "dried off" or, essentially, forced to stop producing milk by not taking any more milk from them for the next two months until they calve.
The belief that a cow must become pregnant in order to produce milk is purely myth .
Cows only become pregnant to produce a calf, and only produce milk with the intent to feed that calf.
That a cow becomes pregnant and is producing milk is purely coincidental due to the overlap of the length of lactation period (6 to 8 months for beef cattle, 10 months for dairy) and the gestation period (approximately
9.5 months in all female bovines). , The below pregnancy tests, if they can be called that, are inaccurate as best and should only performed on females that are in late pregnancy, i.e., from months 5 to
9.
They should not be counted as reliable tests for determining pregnancy especially with inability to perform such tests at early gestation, and because results confirming pregnancy are less of a guarantee than other more reliable methods mentioned in the next section.
However, they can be done purely out of curiosity and interest in seeing the physical responses of the fetus when one or more of such tests are performed.
Abdominal ballottement (bumping).
This can only be used in females that are five to seven months into their pregnancy.
To feel for the fetus, use the following technique:
1.
Place your hand or fist against the lower right flank region of the abdomen, then
2.
Make a short, vigorous inward-upward thrust and keep your hand in place.
You will feel the hard fetus come back against your hand.
The amniotic fluid will allow the fetus to recede against your bump but fall back in place almost immediately.
The size of the fetus determines the effectiveness of this technique, which means that it can only be done when the cow is over halfway through her gestation period and not one and a half to three months (45 to 90 days) post-breeding.
Because of that it's not an effective technique for early-detection pregnancy nor for large herds that need to be "preg-checked" in a short matter of time.
It's best for small herds and for producers that would want to feel for a fetal calf that is only a few months away from birthing for curiosity's sake.
Formation of uterine seal or mucosal plug in the cervix.
Typically a pregnant cow will form a seal in the cervix to protect the fetus from foreign bodies (bacteria and soil, mostly) entering the uterus.
The plug can only be seen with a speculum and light that is inserted in the vaginal canal.
The mucosal plug can also be felt via rectal palpation.
This method is not always reliable because the plug is not always readily observed because it may form deeper in the cervix than throughout the entire organ.
Fetal heart beat.
This is best performed after the sixth month of gestation, though detection can be unreliable as it is not as certain as with other classes or species of farm animals as in cows.
Use of a stethoscope is recommended even though pressing an ear against the right lower abdominal region and listening will also yield good results.
The fetal heart beat can be distinguished from the dam with its greater frequency and higher and lighter pitch.
This method is not recommended if the cow is not cooperative nor accustomed to human touch.
Do this only on cows or heifers that are accustomed to your touch and you trust each other enough to be able to do this without a stethoscope and without getting kicked.
Like with bumping cows, this can only be done on those cows in the last two-thirds of their pregnancy, and is not ideal if early detection of pregnancy takes higher precedence than mere curiosity and a willingness to wait for a long period of time before being able to determine pregnancy of a cow or heifer.
Fetal movement.
Patience is much needed to observe voluntary fetal movements on the right side of the cow through the abdominal wall because you just need to wait see such movements.
This can only be done when the cow or heifer is in the latter half of pregnancy, and is certainly not ideal for either early detection or if you wish to have results without waiting for either the right time to detect nor to see any results. , Four primary pregnancy tests are available for producers to choose from in order of cost to use:
Rectal palpation, PAG ELISA with blood and milk samples, and ultrasound.
Such pregnancy tests can be utilized based on the type of cattle (dairy or beef, and even purebred versus commercial), and level of record keeping done.
Some tests are better to use than others based on expense and ease of use, and how well breeding records are kept.
For example, PAG ELISA via either milk or blood testing is not recommended if inadequate and imprecise records are habitually kept for either beef or dairy operations.
The second section below describes the methods to use, what is involved with carrying out such methods and whether it may be right for your herd or not. -
Step 3: Fetal responsiveness to physical or observational pregnancy testing.
-
Step 4: Perform an accurate scientific pregnancy diagnosis to confirm observations.
Detailed Guide
The behaviour of cows and heifers after they have conceived is one of the best non-invasive means of determining pregnancy in cattle.
Simply put, pregnant cattle will not (or should not) come into estrus or "heat" for the entire duration of the
9.34-month (285 day) gestation period.
The estrous cycle in cattle occurs, on average, every 21 days.
If a cow or heifer has aborted or absorbed the embryo, she will soon come into estrus and continue regular cycling until she conceives again.
Embryo absorption, early embryonic death, or fetal abortion can happen at any time during a cow's pregnancy and can be caused by anything, from extreme stress to a disease a cow acquired before or during her gestation.
How to Tell when a Cow or Heifer Is in Estrus fully explains the estrus activity shown by such cows.
Thus if a cow unexpectedly starts to behave like she's in estrus during her pregnancy, particularly if she is several months along, chances are she aborted the fetus and is beginning to get back into regular cycling.
Absorption of the embryo occurs within the first two to three weeks after breeding.
False heats may be experienced by females during the first few weeks post-conception, and though they are rare, they can be easily misdiagnosed by the producer as an actual heat period.
Such suspicions can only be confirmed or rejected if follow-up with a proper test (see below) is completed at least a month and a half after breeding.
Observing behaviour also applies to cows' and heifers' male counterparts.
Bulls will not show any interest to any cows that maintain pregnancy.
They only show interest if a cow comes into heat and when she's ready to calve.
This is because, during both periods, estrogen levels increase every time a cow is one to three days away from coming into heat, and when it's time for the calf to be born. (At birth, the fetus sends stress signals to the dam's nervous system which starts a cascade of hormonal events, such which largely includes progesterone levels decreasing and estrogen increasing.) A bull can sense this through performing what's known as the "flehmen response" where he "tests," via drinking, the urine of a female to check for pheromone activity.
The bull tilts his head up high and back as far as he can to allow the fluid to drain into a sensory organ in his nasal passage called the Jacobson organ.
Curling his upper lip up allows the urine to flow into this organ as deep as possible to better test for pheromone activity.
High levels of progesterone in the cow's system, which would be present in the urine, will tell a bull that she is not available for his services.
Besides getting a little bit of a head-butt to the ribs from the cow herself in displaying her disappointment in his flirtatious advances, it also tells him that it's probably best to find another female that would potentially be in more need of his amorous intentions.
Changes to size and shape of body parts can be noticed in both cows and heifers, primarily with the abdomen (or "barrel"), and the udder.
Unlike humans, cows do not typically show their "baby bump" until they're about half-way through gestation.
Only after then do you begin to see how the cow or heifer is getting larger in the abdominal region.
By mid- to late-third trimester when a cow or heifer is considered "heavily pregnant," she synonymously looks quite like a large, round barrel with a head, a tail, and four legs.
In heifers, the udder begins to fill out more and reach maturity.
Heifers that are "virgin" or not yet conceived will have an under-developed udder that is only resembled by the presence of four small teats tucked up under their belly between their hind legs.
As they progress into their gestation period, the udder gradually becomes more prominent until she gives birth.
A heifer will not have as defined an udder as a mature cow will (nor even a mature dairy cow), but it will be as big an udder as a heifer will need to feed her newborn calf.
Mature cows already have a fully developed udder so there will be no change in the physical structure of the mammary organ as in the bred heifers.
Cows also will not begin to fill up with milk until they are showing signs that calving is imminent.
However, a cow that is pregnant and still has a calf to suckle will continue to produce milk until that calf is weaned.
With dairy cows, when they successfully conceive and become pregnant they will continue to lactate until they are "dried off" or, essentially, forced to stop producing milk by not taking any more milk from them for the next two months until they calve.
The belief that a cow must become pregnant in order to produce milk is purely myth .
Cows only become pregnant to produce a calf, and only produce milk with the intent to feed that calf.
That a cow becomes pregnant and is producing milk is purely coincidental due to the overlap of the length of lactation period (6 to 8 months for beef cattle, 10 months for dairy) and the gestation period (approximately
9.5 months in all female bovines). , The below pregnancy tests, if they can be called that, are inaccurate as best and should only performed on females that are in late pregnancy, i.e., from months 5 to
9.
They should not be counted as reliable tests for determining pregnancy especially with inability to perform such tests at early gestation, and because results confirming pregnancy are less of a guarantee than other more reliable methods mentioned in the next section.
However, they can be done purely out of curiosity and interest in seeing the physical responses of the fetus when one or more of such tests are performed.
Abdominal ballottement (bumping).
This can only be used in females that are five to seven months into their pregnancy.
To feel for the fetus, use the following technique:
1.
Place your hand or fist against the lower right flank region of the abdomen, then
2.
Make a short, vigorous inward-upward thrust and keep your hand in place.
You will feel the hard fetus come back against your hand.
The amniotic fluid will allow the fetus to recede against your bump but fall back in place almost immediately.
The size of the fetus determines the effectiveness of this technique, which means that it can only be done when the cow is over halfway through her gestation period and not one and a half to three months (45 to 90 days) post-breeding.
Because of that it's not an effective technique for early-detection pregnancy nor for large herds that need to be "preg-checked" in a short matter of time.
It's best for small herds and for producers that would want to feel for a fetal calf that is only a few months away from birthing for curiosity's sake.
Formation of uterine seal or mucosal plug in the cervix.
Typically a pregnant cow will form a seal in the cervix to protect the fetus from foreign bodies (bacteria and soil, mostly) entering the uterus.
The plug can only be seen with a speculum and light that is inserted in the vaginal canal.
The mucosal plug can also be felt via rectal palpation.
This method is not always reliable because the plug is not always readily observed because it may form deeper in the cervix than throughout the entire organ.
Fetal heart beat.
This is best performed after the sixth month of gestation, though detection can be unreliable as it is not as certain as with other classes or species of farm animals as in cows.
Use of a stethoscope is recommended even though pressing an ear against the right lower abdominal region and listening will also yield good results.
The fetal heart beat can be distinguished from the dam with its greater frequency and higher and lighter pitch.
This method is not recommended if the cow is not cooperative nor accustomed to human touch.
Do this only on cows or heifers that are accustomed to your touch and you trust each other enough to be able to do this without a stethoscope and without getting kicked.
Like with bumping cows, this can only be done on those cows in the last two-thirds of their pregnancy, and is not ideal if early detection of pregnancy takes higher precedence than mere curiosity and a willingness to wait for a long period of time before being able to determine pregnancy of a cow or heifer.
Fetal movement.
Patience is much needed to observe voluntary fetal movements on the right side of the cow through the abdominal wall because you just need to wait see such movements.
This can only be done when the cow or heifer is in the latter half of pregnancy, and is certainly not ideal for either early detection or if you wish to have results without waiting for either the right time to detect nor to see any results. , Four primary pregnancy tests are available for producers to choose from in order of cost to use:
Rectal palpation, PAG ELISA with blood and milk samples, and ultrasound.
Such pregnancy tests can be utilized based on the type of cattle (dairy or beef, and even purebred versus commercial), and level of record keeping done.
Some tests are better to use than others based on expense and ease of use, and how well breeding records are kept.
For example, PAG ELISA via either milk or blood testing is not recommended if inadequate and imprecise records are habitually kept for either beef or dairy operations.
The second section below describes the methods to use, what is involved with carrying out such methods and whether it may be right for your herd or not.
About the Author
Brittany Mendoza
Experienced content creator specializing in home improvement guides and tutorials.
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