The influence of LED lighting on the physiology and behaviour of broiler chickens

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Poultry management can have significant impacts on bird production and welfare. My previous research has focused on a number of management practices, including the use of lighting programs (daylength). This work has now been implemented world-wide to improve bird welfare and productivity. In 2014, Natural Resources Canada legislated a ban on incandescent bulbs, commonly used in poultry barns. Light emitting diode bulbs are a logical replacement, as they are inexpensive to operate. Despite research focusing on poultry responses to LED's increasing in frequency in the last two years, some gaps in our knowledge remain. For example, looking at the impact of graded levels of wavelength on melatonin production, and the impact of melatonin on production and welfare parameters, has received only minimal attention. To address this gap, four specific short-term objectives have been identified, comparing broiler responses under one of 4 light wavelengths (475 nm [blue], 510 nm [green], 570 nm [yellow] and 650 nm [red]). With use of data regression analysis (used in my four published works on daylength), dependant variable response curves will be derived. The objectives include: Objective 1: We will determine if birds prefer one wavelength over another. An undergraduate student will work with me on this section. Objective 2: This work will facilitate understanding of how wavelength impacts productivity characteristics, including time of growth (important for health), mortality and morbidity levels, lameness, bird behaviour, muscle yield, melatonin and growth hormone (IGF-1) production. This section will be led by a Ph.D. student. Objective 3: This work will determine the impact of melatonin production on growth, health and welfare of broilers. By altering blood melatonin levels via feeding exogenous melatonin in this unique study, we (led by Ph.D. student) will establish if melatonin impacts these variables. Objective 4: My previous work with daylength has been adopted world-wide because of the improvements in welfare and productivity that are achieved by varying darkness length each day. If light wavelength alters the amount of light that reaches the brain of the bird, it is possible that an interaction between daylength and wavelength could exist. This work section will be led by the M.Sc. student. In conclusion, this work has the potential to find relationships between production and behaviour response variables in broilers, and link them to potential differences in melatonin production. As a complete package with well-replicated science, the publications resulting from the work will aid producers in their decision of light choices, and provide consumers comfort in understanding their food comes from ethically responsible production systems. The training of three HQP in poultry welfare and management will benefit the Canadian poultry industry in the future.