Researchers Identify Pheromone that Activates Female Goats' Reproduction

Citrus-scented ingredient in the goat odor doesn't just attract female goats, but also turns on their reproduction systems, a new study has reported.

According to researchers at The University of Tokyo, a newly identified pheromone causes long-term physiological changes such as ovulation. The chemical works by increasing activity in central reproductive axis in female goats.

The study was done on goats. However, the brain's reproductive center is highly conserved in all mammals, meaning that the research might apply to other livestock and humans.

It was already known that the goat essence triggers the activity of a hormone (called gonadotropin-releasing hormone) linked with reproduction in female goats. Now, researchers have found the exact pheromone in the 'eau de male goat' that causes the physiological changes in female goats.

The term pheromone was coined by Karlson and M. Luscher in 1959. Pheromones are chemicals used by a given species that affects the behavior of the same species.

For the study, researchers attached special hats with gas-absorbing balls to the heads of normal and castrated goats. The hats helped the study team collect the essence of the goaty smell, National Geographic reported.

Chemical analysis of the head scent revealed that there were specific ingredients intact in goats. Researchers found that the chemical 4-ethyloctanal was linked with the increase in activity of a brain region responsible for reproduction in females.

"In 4-ethyloctanal, we identified a novel chemical that had never been demonstrated in nature before. This was our first surprise," Takeuchi said in a news release.

According to the researchers 4-ethyloctanal reacts with oxygen to form 4-ethyloctanoic acid, which is a main ingredient of characteristic goat odor.

"We are tempted to speculate that this is a clever reproductive strategy of the male goat to alter behavior and activity of the reproduction center in the female for mating by a single molecule," Takeuchi added.

Goats aren't the only animals that attract females with biological scents. According to a related study, male elephants display their sexual availability by releasing a pungent mixture of chemicals, Livescience had earlier reported.

Pheromones are designed to work within species. However, there are certain chemicals that can operate inter-species as well such as rabbit maternal pheromone 2-Methylbut-2-enal reduces heart rate of nervous dogs. Also, pig pheromone androstenone calms shy horses.

The study is published in the journal Current Biology.