Sorry!
Dhia Hussain Jassim Al Delemi sir!
Your research papers suggested could not depict the actual answer to my question related to cuboni's test.
Cuboni's test is used to detect estrogen levels in urine in pregnant mares that are at least 100 d pregnant, but results are close to 100% accurate if measured by day 150. The estrogen that is detected originates from the foetal gonads and not from the dam. I don't know which kind of estrogen is the one that is exactly measured, but I hope this helps you somewhat.
Thank you Nicole Arana Valencia name!
Thanksfor your positive reply
Dear Mehrajuddin.
I agree with Nicole. More about the types of estroges that can be measured in urine can be found in Current Therapy in Large Animal Reproduction (Youngquist et Threlfall, 2007):
Estrogen is produced by the conceptus as early as day 12, but concentrations of estrogens in maternal blood are not detectable until after 35 days. Estrogens may be bound to sulfates (conjugated) in the serum or plasma or be free (unconjugated). The concentrations of conjugated estrogens are 100 times greater than unconjugated estrogens.
Equilin and Equilenin are ring-B saturated estrogens unique to the mare and present in the urine after 4 months of gestation. Estrogens have been measured in feces and urine. Although serum concentrations of estrone sulfate increase a few weeks after conception, a dramatic increase occurs after 60 days of gestation that can be detected to diagnose pregnancy. After 150 days of gestation, the conceptus produces sizable amounts of estrone sulfate, which are excreted in the mare’s urine.
Estrone sulfate concentrations not only indicate that the mare is pregnant, but provide information on the well-being of the conceptus. Concentrations of estrogens decrease rapidly if fetal death occurs. Biologic tests have been replaced with chemical assays for estrogens. Radioimmunoassay combined with column chromatography separation was developed to measure low concentrations of estrogens early in pregnancy. Estrogens can be measured in a blood, urine, fecal, or milk sample. Simpler chemical tests are available that can easily measure the high concentrations of conjugated estrogens in urine, including the Cuboni test.
Hope this helps!
Regards,
Jiri
Estrogen hormone is detected in Cuboni test for pregnancy diagnosis in mare and camel.
Source of this Estrogen hormone is the foetal gonads that’s why this test can be carried out in second half of the gestation because in first half,there is no much development of Foetal gonads .