Investigated Grill Lighting Preferences in Brazilian Research
Vision is crucial for fowl behaviour and welfare. Poultry possess highly specialised visual systems, with the majority of their behaviour being influenced by vision, as stated by Angélica Signor Mendes from the Technological Federal University of Paraná in Brazil, along with co-authors from Purdue University in the US and Brazil's State University of Campinas.
A study published in the Journal of Applied Poultry Research assessed the lighting preferences of grill chickens subjected to various illumination sources and their output performance.
In general, birds subjected to light-emitting diode (LED) lighting exhibited superior performance compared to those raised under compact fluorescent lamps (CFL). Seven-day-old male broilers illuminated by LED lights exhibited superior feed efficiency compared to their counterparts under CFL lighting.
In the initial trial, the researchers assessed avian preference for white and yellow illumination emitted by LED lights. Bird preference was evaluated by films captured during the trial. In a subsequent experiment, they examined the performance of grill chickens subjected to LED and CFL lighting.
Performance was evaluated based on mortality rate, avian body weight, daily weight gain, feed intake, and feed conversion ratio.
The chickens inhabited spaces illuminated by yellow and white LED illumination uniformly and exhibited no behavioural preference for either habitat. Birds consumed more food at 21, 28, and 35 days of age under white LED lighting conditions.
Mendes and co-authors observed that birds subjected to LED lighting had superior production performance compared to those under CFL lighting. Seven-day-old male chicks exhibited superior feed conversion under LED lighting compared to their counterparts of the same age under CFL lighting.
Swiss Research Examines Various Light Spectra for Egg-Laying Hens
Findings from a trial in Switzerland indicated that laying hens exposed to green light exhibited increased exploratory behaviour, while red light resulted in less aggression compared to white light. The research corroborated earlier findings that red light hastens sexual maturation, attributing the effect more to wavelength than to light intensity.
Researchers at Bern University of Applied Sciences indicate that the optimal way for illuminating poultry buildings has been a topic of considerable interest for decades, particularly as new systems emerge. Beat Huber-Eicher and colleagues elucidate in their publication in Poultry Science that poultry producers are progressively employing coloured LEDs to illuminate hen houses, particularly in Germany, Austria, the Netherlands, and England. In Switzerland, it is reported that all new systems are now outfitted with LED technology, typically in green.
LEDs provide monochromatic light across many wavelengths and offer numerous advantages over traditional light sources, including superior energy efficiency, extended lifespan, excellent reliability, and reduced maintenance expenses.
The study investigated the impact of white, red, and green LED illumination on the behaviour and production metrics of laying hens. The light intensity in the three treatments were calibrated to be viewed as equivalent by the chickens.
Twenty-four groups of 25 laying hens were housed in identical compartments measuring 5.0 by 3.3 meters, each furnished with a litter area, elevated perches, feeding and drinking apparatus, and nesting boxes. Initially, they were maintained under white LED lighting during a two-week acclimatisation phase.
Over the subsequent four weeks, eight randomly selected compartments were illuminated with red LED (640nm) and an additional eight with green LED (520nm). Behaviour was observed over the final two weeks of the trial. Furthermore, weight gain, feed intake, beginning of laying, and laying performance were documented.
The findings indicated little impacts of green light on exploratory behaviour, however red light diminished aggressiveness in comparison to white light. The findings corroborated prior studies indicating that red light expedited the sexual maturation of laying hens, with Huber-Eicher and colleagues concluding that this impact was attributable to the precise wavelength rather than the light's intensity. They noted, however, that the potential impact of light intensity should not be disregarded.
