1. The test is based on the presence of the alpha
hormone (oestrin) in the urine of the pregnant mare.2. A total of 39'7 tests were carried out on 115
equines. Positive results were obtained in 282
tests and. negative results in the remainder.3. The number of mares that were notified as being
pregnant was 37 and positive results were obtained
in 38 cases, one mare proving to be not in foal.
The error in pregnant mares is therefore 2.7 per
cent.4. Twenty -eight non- pregnant mares were examined
and the test was correct in each case.5. A gradual increase in the concentration of the
hormone in the urine throughout the period of
pregnancy was noted. 800 m.u. per litre was found
on the 47th day of pregnancy and towards the end of
the period over 166,000 m.u. per litre.6. The diagnosis of pregnancy was based on a quantitative estimation of the hormone. 1,000 m.u.
per litre was regarded as the minimum amount on which
a positive diagnosis could be made.7. The earliest time at which it was possible to
diagnose pregnancy by this method was at the 65th
day after mating.8. Thirty -five hours after foaling the concentration
of the hormone had fallen to 800 m.u. per litre,
and after sixty -one hours it was less than 300.9. The alpha hormone was found in the urine in a concentration of 300 -800 m.u. per litre during
oestrus and of 160 units during the inter -oestral
and ancestral periods.10. Similar amounts to that found during oestrus
were discovered in the urine of two nymphomaniac
mares.11. Milk from a lactating mare failed to reveal
signs of this hormone.12. The alpha hormone in the urine of mares was
not soluble in ether.13. No sign of anterior pituitary hormones, rho
one and rho two, was noted and therefore it was concluded that it was not possible to diagnose early
pregnancy in the mare by the presence of the rho
one factor in the urine
