Acyline to Suppress Stallion Testosterone Levels

Researchers determined that acyline can reduce stallion testosterone concentrations to as low as those of geldings.
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For some breeders, lowering a breeding stallion’s testosterone concentrations in the off-season is, among other uses, an attractive solution for undesirable behaviors. They can do this by administering a substance that suppresses the horse’s hypothalamic-pituitary-gonadal (HPG) axis, which regulates testosterone concentrations.

Gabriel M. Davolli, DVM, MS, a theriogenology resident at Louisiana State University’s School of Veterinary Medicine, studied one gonadotropin-releasing hormone antagonist’s effects on suppressing the HPG axis and presented his results at the 2015 American Association of Equine Practitioners Convention, held Dec. 5-9 in Las Vegas. He conducted his research while completing his master’s degree at the University of Kentucky’s Gluck Equine Research Center, in Lexington.

Gonadotropin-releasing hormones (GnRH) essentially tell the stallion’s reproductive system to produce testosterone. The appropriate antagonist would block this function

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Alexandra Beckstett, a native of Houston, Texas, is a lifelong horse owner who has shown successfully on the national hunter/jumper circuit and dabbled in hunter breeding. After graduating from Duke University, she joined Blood-Horse Publications as assistant editor of its book division, Eclipse Press, before joining The Horse. She was the managing editor of The Horse for nearly 14 years and is now editorial director of EquiManagement and My New Horse, sister publications of The Horse.

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