A team of scientists at Texas A&M’s School of Veterinary Medicine & Biomedical Sciences have found evidence that phenylbutazone or “bute”, a common non-steroidal anti-inflammatory drug, may prevent a mare’s egg cells, or oocytes, from turning into viable embryos, a vital step in equine assisted reproduction such as IVF (in-vitro fertilization) and oocyte transfer.
The study was published in the veterinary journal Theriogenology. One of the researchers who took part in the study, Luisa Ramirez-Agamez, from the VMBS’ Department of Large Animal Clinical Sciences, explained to AG Daily, “In horses, in-vitro fertilization is more intricate than in humans. Mare oocytes need about 30 hours to mature in the lab after collection before fertilization. Then, the eggs must be injected with sperm to induce fertilization, a method known as Intracytoplasmic Sperm Injection (ISI).”
According to the study, mares who were given bute for 10 consecutive days showed a decrease in viable eggs.
“We found that phenylbutazone, or bute, can negatively impact both the maturation of mare oocytes and the development of fertilized eggs into viable embryos,” Ramirez-Agamez added. “Eggs affected by bute cannot be utilized in assisted reproduction.”
