Scientists discover new ovulation assessment

Tokyo-

A mare's blood plasma sample can apparently just as accurately confirm when ovulation occurs as can a veterinarian's rectal palpation assessment, new research, reported by The Horse.com, shows.

Plasma hormone concentrations before and after ovulation were studied by a team led by Yasuo Nambo, DVM, Ph.D., of the Japan Racing Association Equine Research Institute. The concentration of inhibin, which inhibits synthesis of follicle-stimulating hormone, and inhibin pro-aC more than doubled within hours after ovulation, researchers say. The increase may be due to absorption of inhibin (from the follicular fluid released by the ruptured follicle) via the abdominal cavity, rather than an increase in the mare';s secretion of inhibin.

Nambo's team inserted 50 mL of equine follicular fluid (eFF) in the abdominal cavity and measured plasma levels of inhibin.

"Levels of inhibin were significantly higher in eFF-treated mares than in control mares," explains Nambo.

Researchers hope the test will develop to give faster results and allow efficient use of artificial insemination with frozen semen.

"We believe that measurement of circulating inhibin is more useful than frequent rectal palpation in making embryo transfer, because it is accurate, convenient, and easy to check a lot of mares by one assay," says Nambo.

He and fellow researchers plan to research methods of endocrine diagnosis for equine reproductive disease.

The study was sponsored by the Japan Racing Association.