| dc.description.abstract | As duck production becomes more prevalent on a global scale, modern duck housing systems must maximize duck productivity. The welfare of an animal influences its productivity, and is therefore useful in evaluating which environmental factors, such as artificial lighting, are more favorable in duck production systems. However, limited research has examined the manipulation of photoperiod and light spectrum on Pekin duck welfare and growth. Four experiments were conducted to determine the effects of (i) two photoperiods, (ii) two commercially available LED fixtures, (iii) ultraviolet (UV) light supplementation, and (iv) four experimental monochromatic LED fixtures on Pekin duck growth, stress, and fear responses during a 35 d grow-out period. Ducks reared under a 20L:4D photoperiod had more efficient nutrient metabolism and stronger humoral immune response to Newcastle Disease Virus vaccine due to improved FCR and decreased stress and the effects of stress compared to ducks reared under 16L:8D. Ducks subjected to white/red LED lighting had lower stress susceptibility and fear responses compared to those subjected to white/blue LED lighting, indicating duck welfare may be compromised by blue LED light exposure, even at supplemental levels. Ducks exposed to supplemental UV light had narrower and lighter eyes and lower acute and chronic stress susceptibility compared to ducks not subjected to UV light (control). UV ducks also had a faster latency to first head movement during tonic immobility (TI) and required more attempts to induce TI than in the control ducks. These results indicate supplemental UV lighting can lower stress and fear responses in Pekin ducks and increase duck welfare. Exposing ducks to monochromatic red and blue LED lighting elevated the stress response of ducks and decreased eye weight compared to white and monochromatic green LED light. This indicates blue and red lighting may not be adequate for Pekin duck grow-out, and Pekin ducks may require artificial light sources containing a broad range of wavelengths, as seen with white and green lights. The current findings indicate Pekin duck welfare and performance can be influenced by artificial lighting duration and spectrum and emphasize the importance of choosing correct artificial lighting for Pekin ducks. | |
