In a three-year experiment conducted by the Yamagata prefectural government's research team, it was discovered that white stripes created using bleach or white spray on the coats of Japanese Black cattle have a dual purpose. Not only do these stripes give the cattle a striking appearance akin to zebras, but they also serve as a protective barrier against blood-feeding insects such as gadflies and cattle flies, thereby reducing the stress levels in the animals.
Grazing beef cattle offer several advantages to farmers, including cost reduction on feed and labor due to their grass consumption and the utilization of idle farmland. However, these outdoor cattle are susceptible to blood-feeding insects, which can cause pain, itchiness, and potential sickness from disease-carrying bugs, ultimately impacting their reproductive power. The positive effect of stripes on repelling insects was previously observed in Aichi Prefecture, prompting the Yamagata prefectural government to conduct experiments from 2021 to 2023 to confirm this impact on Japanese Black cattle in their region.
By creating 3-4 centimeter-wide stripes on the cattle's coats with bleach or white spray, the researchers noticed an immediate decrease in insect-related movements, suggesting that the stripes were effective in repelling gadflies and cattle flies. Feedback from farmers who participated in the experiment was positive, with one noting the visible reduction in tail-wagging and other insect-avoidance behaviors in the striped cattle. Additionally, concerns about possible negative reactions from conventional-looking cattle towards those with stripes proved unfounded, as the striped animals were not ostracized for their unique appearance.