Effects of Ultraviolet Light Supplementation on Pekin Duck Production, Behavior, and Welfare

Abstract

Ducks, like other domestic poultry species, can visualize the ultraviolet (UV) portion of the light spectrum; however, the importance of UV light radiation in artificially lit duck growout facilities remains unknown. The objective of this study was to determine the effects of UV light supplementation on Pekin duck production parameters, eye development, stress, and fear. Pekin ducks were reared with light-emitting diode (LED) lights supplemented with UV light or just LED lights (control). There were no differences in body weight (p = 0.32), feed conversion ratio (p = 0.38), or gait score (p = 0.89). Differences in eye morphology were observed, with ducks reared under UV light having narrower (12.3 ± 0.06632 mm; p = 0.010) and lighter (1.46 ± 0.01826 g; p = 0.025) eyes than the control (12.5 ± 0.05583 mm; 1.53 ± 0.02386 g). Ducks reared in UV environments had lower acute and chronic stress susceptibility with lower plasma corticosterone (6317 ± 593.79 pg/mL; p = 0.024), heterophil to lymphocyte ratios (0.43 ± 0.02889; p = 0.035), and composite asymmetry (0.58 ± 0.0298; p = 0.002) than control ducks (9242 ± 1120.7 pg/mL; 0.54 ± 0.04212; 0.76 ± 0.03726 mm, respectively). Ultraviolet ducks had a faster latency for the first head movement during tonic immobility (61.28 ± 9.4863 s, p = 0.026) and required more attempts to induce tonic immobility (1.71 ± 0.07333, p = 0.018) than control ducks (100.7 ± 14.846 s and 1.48 ± 0.06478, respectively). There were no differences in inversion testing (p = 0.91). These results indicate that UV lighting can lower stress and fear responses in Pekin ducks and can therefore increase welfare. Additionally, this study emphasizes the importance of choosing correct artificial lighting for all poultry species.

Application of Ultraviolet Light for Poultry Production: A Review of Impacts on Behavior, Physiology, and Production

“…There are even fewer studies that have explored how UV light affects ducks. House et al (2020b) investigated the effect of supplemented UVA light on duck welfare and production parameters, where day-old ducklings were reared under LEDwhite light or LED-white and UVA light for 35 days. The ducks exposed to the UVA wavelengths showed several improvements in welfare parameters and stress measures such as lower fear responses and lower composite asymmetry although no effects on production parameters of body weight or feed conversion ratio were seen (House et al, 2020b).…”

“…House et al (2020b) investigated the effect of supplemented UVA light on duck welfare and production parameters, where day-old ducklings were reared under LEDwhite light or LED-white and UVA light for 35 days. The ducks exposed to the UVA wavelengths showed several improvements in welfare parameters and stress measures such as lower fear responses and lower composite asymmetry although no effects on production parameters of body weight or feed conversion ratio were seen (House et al, 2020b). The morphology of the duck's eyes was also different depending on the light environment they were reared in House et al (2020b) emphasizing the physical impacts that could affect perception of their surroundings.…”

“…The ducks exposed to the UVA wavelengths showed several improvements in welfare parameters and stress measures such as lower fear responses and lower composite asymmetry although no effects on production parameters of body weight or feed conversion ratio were seen (House et al, 2020b). The morphology of the duck's eyes was also different depending on the light environment they were reared in House et al (2020b) emphasizing the physical impacts that could affect perception of their surroundings. The role of UVA light in foraging has been suggested to be less important for ducks that would typically feed underwater compared with species that feed on land (Barber et al, 2006), but its role in signaling for domestic ducks is uncertain.…”

Experimental monochromatic light-emitting diode fixture impacts Pekin duck stress and eye development

“…Tibia bone breaking strength and ash mineral content were analyzed using the left and right tibias of 20 randomly selected birds per treatment (n = 160) respectively on d 35 ( House et al., 2020 ). All ducks were euthanized in airtight chambers using a mixture of CO2 gas and air.…”

“…Individual weights of each eye (g) were recorded. The average eye length, width, weight and the differences in each measurement between the left and right eyes of each sampled duck was calculated as in House et al. (2020) .…”