new blood test predict horse foal date - predicts foaling mare time

With the high incidence of foaling death in miniature horses, hundreds of miniatures die unnecessarily because of the birthing problems associated with un-assisted labor. This miniature horse foaling blood test provides miniature horse breeders with an opportunity transport their mare to a vet hospital where a medically-trained staff be present to assist in the delivery.

Use of these blood and milk tests, combined with a commitment to have the miniature horse mare foal in a medical facility, promises to save the lives of thousands of miniature horses and foals.

According to vets, this blood test for horse mares can pinpoint the due date (within 24 hours) when multiple samples are taken during the last two weeks of pregnancy and combined with milk tests. This blood test tracks the relationship between progestogens and total estrogens prior to foaling.

Here is partial text from the betlabs web site (by clicking the "Pregnancy testing" link:

Pregnancy Testing in The Mare

Progesterone assay alone will not confirm the mare is pregnant. Progesterone assays will tell you if the mare is producing enough of this hormone to maintain the pregnancy.

B.E.T. prefers to test for PMSG (pregnant mare serum gonadotropin) also known as Equine Chorionic Gonadotropin, when mares are between 45 and 90 days pregnant. This test has approximately a 5% false negative rate and a 10% false positive rate. PMSG values above 1 I.U. per ml are considered positive; however, normal values are between 10 and 100 I.U. per Ml. Mares which are below 10 I.U. but pregnant may be at risk of losing the pregnancy unless maintained on progestin therapy.

From 90 days to term, total estrogen assays are used to confirm pregnancy and monitor fetal viability. This test includes estrone sulfate and is approximately 99% accurate. Total estrogen assays work best between 100 days and 2 weeks prior to foaling.

Days of pregnancy	Total Estrogens Mean concentrations (pg/Ml)
barren/open 90-100 100-110 110-120 120-130 130-140 140-150 150-320	5-50 75 205 356 469 857 1040 greater than 1000

Approximately 2 weeks before foaling, estrogen levels fall rapidly to approximately 300pg/Ml.

Progestogens rise and total estrogens fall prior to partutition in the mare. The rapid rise in progestogens is thought to be due to corticoid secretion by the fetus. The typical relationship between progestogens and total estrogens prior to foaling is shown below. Not all mares follow this pattern. Alkaloids in the fescue and other plants prevent the dramatic rise in progestogens. The mechanism of this action is unknown.

MEAN CONCENTRATIONS PRIOR TO BIRTH

Days to Parturition	Progestogens (ng/Ml)	Total Estrogens (pg/Ml)
15 10 9 8 7 6 5 4 3 2 1	4.8 8.2 10.1 14.1 21.0 25.0 27.0 29.0 31.0 35.0 36.0	3300 2100 1700 1600 900 850 600 550 400 410 300