08/27/2024
EARLY CALVING…
There are many reasons why cattle may calve early or even go past their expected due date. After
looking into the many possible contributing factors of early calving, I want to share some valuable
insights that I've gathered. We learn every day in this industry and as we evolve so does the available
information. Some of this may seem basic but sometimes, basics are the best starting points.
On average cattle gestation is around 283 days or for my fellow month trackers 9 months, 1 week, and 6
days. However, did you know this can vary from breed to breed? That’s right, it’s not a one-gestationperiod-fits-all breeds. So how do you accurately predict when calving will occur? Great question, right!
The best answer is… get to know your breed, study your herd, tract your breeding program. This applies
to mixed breeds as well, there will still be a gestation period for them.
For us, we tract when our bull(s) are placed with the ladies and when we pull them. We on average run
our bull(s) for around 60 days. This allows us to narrow down our calving window. We do this proactively
because our state's weather can be quite unpredictable. We prefer not to calve in the dead of winter or
the thick of summer as it is challenging for everyone involved. While we cannot predict if all calves will
arrive early, on time, or late, what we do know is, if our bull(s) went in November 25th and we exposed
our girls for 60 days, we should see calves start dropping the first of September and end our calving in
Mid-November. Anything before the first week of September would be considered early. Now keep in
mind a week or so early is not uncommon, this does not mean the calf is premature, again every breed
gestation period varies.
Another interesting fact is calving gestation can vary based on whether the expecting calf is a heifer or a
bull. Heifer calves tend to arrive earlier, while bull calves tend to have a long gestation period. This is also
why typically your bull calves are larger than your heifer calves. It is thought that bull calves tend to bake
longer due to hormonal factors.
Calf development is influenced by you guessed it “genetics”. Both dam and sire play a pivotal role in calf
size and gestation. Many breeders, including us often attribute specific calf sizes to the bull. For
example, have you ever heard of a heifer bull? This is a bull known to produce smaller calves and tend to
be used on heifers. While the bull does impact the size of the calves, it's important to note that both
parents contribute to this outcome. If both parents possess the genetic makeup for a smaller size and
shorter gestation, the calf will inherit those traits. Conversely, if both parents have different genetic
traits, it becomes uncertain what the calf will inherit.
Some breeders prefer to steer a bull calf that arrives late, as these calves are more likely to produce
calves them self that require longer gestation and will likely produce heavier calves. Depending on your
program, you may think this doesn't affect your program, but consider the impact this could have on
your herd's health. Longer gestation periods and larger calves can take a toll on the reproductive abilities
of your heifers/cows over time.
More to come on calf gestation but for now I will close this post with some calving signs…
• Isolation
• Udders bloom - this can start as early as 6 weeks before calving or bag up overnight of calving
• Mucus Discharge
• Ho**er cooter swollen & lucy goosy
• Soften / Sunken Pelvic Ligaments
• Body Temperature Drop
