Japanese farmers paint cows to look like zebras to repel blood-sucking flies

Black cows with white stripes are less likely to stomp their feet, wag their tails or shake their heads to ward off flies than their counterparts.

Farmers in Yamagata Prefecture, Japan, painted their cows with zebra-like stripes to repel blood-sucking insects , Interesting Engineering reported on March 18. This experiment is showing results as the painted cows show fewer signs of stress than their counterparts.

Cows painted in zebra-like stripes in Japan. (Photo: PLOS One).

Japanese black cattle are one of four cattle breeds used as a source of high-quality wagyu beef in the country. However, they are suffering from harassment from blood-sucking insects such as buffalo flies and cattle flies. The stress caused by the insects is so great that some farmers say the fertility rate of their herds has decreased.

To fix it, farmers in Yamagata use spray paint or mild detergent to add white stripes to the black-haired cows, making them look like zebras. This effort has been going on for more than 3 years. After seeing the improvement in the condition of their livestock, more farmers adopted this low-cost method.

Local scientists observed painted and unpainted cows in agricultural lands and noted behavioral patterns such as tail wagging, head shaking or foot stomping to repel flies. While unpainted cows performed these behaviors up to 16 times per minute, painted cows performed these acts only 5 times.

Local scientists have not shared details about the exact reason why flies dislike striped surfaces. In 2019, a group of experts from the Aichi Agricultural Research Center in Nagakute city, Aichi province, Japan, conducted research with 6 cows and published the results in the journal PLOS One . Research shows that zebra-striped cows can avoid attacks from blood-sucking flies , but they did not conduct any experiments to determine the specific cause.

Farmers often rely on insecticides to solve the problem. However, insects tend to develop resistance to drugs within about a decade, leading to the need to develop new and more potent drugs. Striping is a cheaper, short-term alternative. This solution can develop from using external marking paint to identify livestock.

Additionally, previous research has shown that striping on cattle leads to light polarization. This makes it difficult to detect movement, preventing the insect from slowing down in time to land on the animal. Therefore, this method is effective in preventing insect bites.