Miniature Ventures
Breeders of beautiful Miniature Horses with Action!
Quality Breeding  ~  Quality Transport

Larry, Maryann & Brianna Cerullo
5643 SW Minson Rd.
Powell Butte, OR 97753
Phone: 541-410-6222   

E-mail: miniv@coinet.com


We've been breeding miniature horses for nearly twenty years.  One of the most difficult things about being a breeder is coming up with an accurate date for a mare to foal.  We used to hand breed every one of our mares and carefully record every breeding date.  As our numbers increased, it became impractical to hand breed all the mares and we started pasture breeding.  Because we are here most every day and outside and with the horses, we have seen  most of the mares get bred by the stallion they were with.  Once you've been breeding for a while, you'll soon learn to see the signs of a mare being in season.  We record on our calendars when we see mares in a heat cycle as well as any breedings that we have witnessed.

The optimum number days for a mare to carry a foal is about 335 days.  At least that's what the textbooks tell us.  However, we've had foals here (extremely premature) at 280 days and at 370!  So much for the text book.  Larry doesn't bother counting days anymore.  He looks at the last breeding date, jumps forward a year and subtracts a month and two weeks (6 weeks total). That gives 323 days.  It's about this time we start worrying about a mare foaling.  At this point, we had long ago brought her closer to the barn but at that 323 days, we start looking for "signs".  Signs are many and are listed in another article but at about this time, we start using "milk test strips" if the mares are producing some liquid.. 

Milk testing is not fool proof.  There is no test we are aware of that is 100% reliable.  Milk Test strips are a "tool" we use to help plan our diligence but we use them along with watching the other signs. The biggest disappointment for many people is that the milk test strips don't guarantee foaling is going to occur at the time the strips indicate, at least not exactly at that time.

When we first started breeding, we went to a foaling clinic at Larry and Joanne Ross' Scott Creek Farm.  It was there we were introduced to milk test strips and learned how to use them.  They have a wonderful article titled, Milk Test Strips to Predict Foaling.  Do they really Work?  I won't duplicate all of what they wrote here although many of our experiences have been similar.

Milk Test strips are available from a variety of sources.  We used to buy them only from a company called Nurenberg Scientific Supply in Portland, OR.  Cost for them was about $40 for 100 test strips. We ran out one year and bought test strips from a vendor at a horse show.  The strips we bought were called Sofchek Milk Test Strips.  There was a label around the bottle that covered the original packaging.  The label had the vendor's name and the instructions for using the strips.  There were fifty strips in the container.  About the same time, we bought a hot tub spa.  With the spa, a package of "Sofchek Water Testing Strips" was delivered.  Hmmm.  I peeled the label off the package of "milk test strips" and the container was identical.  The hot tub dealer charged $9.95 for the container.  The horse vendor charged $19.95.  Since that experience we have used strips purchased locally.

Milk Test Strips are nothing more than pool test strips that test for water hardness among other things.  Water hardness roughly equates to the calcium level in a mare's milk.  As the mare gets close to foaling, the amount of calcium increases in her milk and the test strips do a wonderful job of showing that is happening.  No matter what test strip you use, there is a graph that shows color changes on the strip.  Here's an example: 
milkteststrips.JPG Not all the all the graphs nor colors are going to be the same on different varieties but they are going to act the same. 

Testing the milk is a relatively easy process.

  • Using a small container, collect milk from the mare.
  • Draw EXACTLY 1 cc of liquid from the container
  • And put it into another clean container.
  • Draw EXACTLY 6 cc's of distilled water and put it into container with milk.
  • Agitate or stir water/milk mixture then dip test strip into solution.
  • Depending on the directions on the container, leave strip in solution for a second or two
  • Then wait for up to 15 seconds (depending on the brand of strips) and compare colors to the graph on container.
  • This test can be done, with a bit less accuracy with half the amount of milk and distilled water.  This is useful when you have a maiden mare who isn't producing much milk.

Using water hardness strips you are watching for the test strip color to work its way to the "very hard level", usually on the right.  As you start testing your mare, the color will likely be at the middle or one color below.  We test daily, in the evening, and will watch the colors slowly creep up to a higher level color.  Often, a mare will "plateau" and remain at the mid-level color or the one below the highest one for some time. Don't get discouraged, this is normal. As your mare gets closer to paturation (foaling) the strips will reflect a "jump" in the calcium level as she has milk ready for her foal.  Generally, when the calcium level reaches the highest point, the mare will foal within 24-36 hours. Remember, though, this is only a tool and can't be counted on as your only indicator the mare is ready to foal.

Additionally, we use pH levels to help us figure the approximate date of foaling.  Generally, we buy test strips that include pH level testing and we've found the pH level test to be a little more accurate than just the water hardness/calcium test.  Here's a photo of the type we buy and a shot of the actual test strip on the left:
The water hardness/calcium level is the top row.  The pH is the fourth row down.  This is a one dip test and the measurements for both are easy to see. Unlike the water hardness/calcium test, in the pH test we are looking for the colors to move left, towards yellow.  These strips have readings going down to pH level 6.2.  Other strips bottom out at 6.4.  Any reading below 6.8 on whatever strip you use, is a sign that the mare will generally foal within 24 to 36 hours.  Readings at 6.4 will indicate a foaling usually within 12-24 hours and readings 6.2 or below indicate the foaling will occur sometime within 12 hours or less.

Using a combination of the water hardness/calcium test and the pH test, we have pretty accurately been able to help predict when a foaling will occur.  However, let me repeat, these tests are not 100% accurate and we've had mares totally fool us with the tests, either foaling before the predicted time or long after. THERE IS NO SUBSTITUTE FOR EXTREME VIGILANCE as a  mare gets close to foaling and the combination of signs plus your experience is the best way of predicting your foaling time.  The consistency and color of the milk, the possible presence of "cow pie" manure, the mare's attitude,  the amount of "yawning" a mare does and so many other little signs are all taken together with these strip results and add up to...the mare is going to have her foal when SHE is ready to and not before!

The hardest part of doing these tests is comparing the colors.  Even after all these years Larry will ask Maryann which color is being indicated.  The thing is, when the mare's milk reaches the highest level of calcium or the lowest level of pH, it is readily apparent.

Supplies needed:

  • Test Strips (we buy ours normally at Wal-Mart)
  • Distilled Water
  • Container to hold mare's milk (we use a film cannister or something similar like the cup that comes with cough medicine)
  • Container to mix distilled water and milk
  • 3cc syringe
  • 6cc or larger syringe