Scientists at Once Innovations Inc. (ONCE), in conjunction with two major U.S. universities, have found that the addition of an ultraviolet A (UV-A) spectrum into animal housing lighting reduces stress levels by a significant margin, representing a breakthrough for poultry animal welfare.

"In our three individual, scientifically conducted trials, we measured two hormonal stress biomarkers and behavioral responses," explained Dr. Aaron Stephan, director of biological research and development at ONCE. "The data show that dynamic levels of UV-A mixed with other specific light spectra result in a substantial reduction of industry-accepted stress indicators. Corticosterone levels decreased by two-thirds, while heterophil:lymphocyte ratios were cut in half when compared to the poultry raised without supplemental UV-A.

"At the same time, the birds exhibited significantly reduced body asymmetry, fear response and wing flapping, as well as a strong preference for UV-enhanced environments. Over the years, we have tried to develop animal-centric lighting that encourages animal behaviors to closely match how they behave in nature. Our studies show that UV-A is an elemental part of a lighting program to achieve the lowest stress and most natural behaviors," Stephan added.

ONCE photobiology research has yielded a better understanding of the importance of UV-A in commercial poultry production. While a popular belief is that adding windows to commercial animal housing enriches the environment and improves animal welfare, the silica glass used in windows blocks beneficial UV-A and causes unnaturally high levels of light in the facilities, the company said. This does not mimic a natural poultry habitat and may, in fact, increase stress and fear levels in chickens.

The ONCE proprietary technology stemming from this research provides an enhanced natural environment that supplements a key light component absent from standard fixtures and from windows.

"Upcoming regulations for poultry animal housing require the installation of windows -- an arbitrary decision that is not supported by scientific evidence," ONCE chief executive officer Zdenko Grajcar stated. "We have engaged several animal welfare organizations in an effort to add UV-A enrichment into the standards and limit the window requirements. Improving animal welfare should result in better overall performance and lower stress. The addition of windows simply does not achieve that."

Founded in 2009, the Minnesota-based company ONCE is a global supplier of research-based animal-centric lighting systems. ONCE leverages photobiology and optogenetics to develop innovative lighting technologies for agricultural animal housing, biosecurity and hatchery markets designed to enhance performance and improve welfare. ONCE agricultural lighting systems are used nationwide in open community chicken, layer and swine housing.