On average, the gestation period of a mare is 340, but it varies between 320 and 370 days! In addition to the Birth Alarm system, we therefore try to anticipate as best as possible the approach of D-day by observing the mare (udders, vulvas) and especially by analyzing mammary secretions. Indeed, by collecting pre-colostrum every day (a very small quantity is enough), it is possible to determine with fairly good precision (72 hours maximum) whether or not we are approaching parturition. The best predictions are obtained by combining the pH test and the calcium concentration test.
pH test
Equipment: strips that test pH between 6 and 8 with an accuracy of 0.2 to 0.3.
Procedure: dip the strip (or place drops if very few secretions are available) on the paper then read the result directly
Analysis of the result: immediately read the result. If the pH is greater than or equal to 6.4, 99% of mares will not foal within 24 hours, 81% will not foal within 72 hours. If below this threshold, 54% of mares foal within 24 hours and 97% of mares foal within 72 hours.
Calcium concentration test
Equipment: Merckoquant 10025 strips (in pharmacies in boxes of 100), with a CaC03 reading scale between 30 and 210 mg/l + a single-use tube or a very clean container rinsed with distilled water + a syringe + distilled water.
Procedure: collect the secretions (what remains after carrying out the pH test) in the syringe. Depending on what we managed to collect (sometimes the mares hit so we take what we can...), suck up 6 times the dose of milk in distilled water into the same syringe. For example, if we were able to collect 0.6ml of milk, we then suck up 0.6*6 = 3.6ml of water. In total in the syringe we will therefore have 0.6+3.6=4.2ml. Empty this syringe into the clean, dry tube/container. To mix, you can re-aspirate/empty the syringe. When it is mixed, take a little of the mixture with the syringe and place a few drops on each square of the strips.
Analysis of the result: we immediately read the result. If 2 pink squares, 90% of mares do not foal before 4 days. If 4 pink squares, 80% of mares foal within 2 days.
To make it easier, we therefore often carry out the pH test and if we are still far from the threshold of 6.4, we do not carry out the calcium test, which is more tedious to carry out (and requires a greater quantity of secretions). Rinse the syringe and container well with distilled water after use.
The figures presented for secretion tests come from the IFCE (available on the internet). So far this has always worked well for our mares, especially combined with observing the mare's body. As a reminder, 60% of mares foal at night.