Lighting in Poultry Flashcards
what are facts about chicken eyes
- large eye size
- highly developed sense of vision
- extended spectral sensitivity (including UV)
- excellent ability to see different colours
What are rods and cones
- photoreceptors found in retina
what is the difference between rods and cones
- rods are associated with night vision
- cones are associated with day vision
what is the correlation to brightness and chickens
- chickens are biologically designed for bright light
- chickens are more active during the day
- research has shown chickens prefer brighter light
- vision is a chickens major method of sensing its environment
how does light enter a chickens brain
2 pathways
1. through the skull into the pineal gland directly
2. eye- hypothalamus - pituitary gland - reproduction and body function
what type of light doesnt penetrate the skull
- low light intesity
- shorter wavelengths may not penetrate the skull as well (blue and yellow light)
what colour of light penetrates the brain better
longer wavelengths like orange to red
how is white light measured? is it effective
LUX
- based on human ability, effective for white light only
why is light intensity important
- manipulated to influence bird behaviour
- positive relationship between light intensity and bird activity
- common industry applications
what happens during low light intensity
- reduce canabolism
- reduced mortality (sudden death syndrome)
- reduce food wastage
- decrease bruising
- imporve feed efficiency
what happens in high light intensity
- eating and drinking
- mating activity
what factors need to be considered when choosing light intensity in broilers and turkeys
- chickens and turkeys prefer higher light intensity
- research suggest minor effects of light intensity on broiler production traits (growth, feed intake and mortality)
- low intensity increased yield of carcass, leg and wing portions in broilers
what factors should be considered in low light intensity for broilers and turkeys
- increases resting and reduces comfort behaviours
- increases breast blistering and foot pad lesions
- increase eye abnormalities and can cause blindness
- helps control canabolism and bullying in turkeys
what are fixed light conclusions
- early brooding - at least 20 LUX
- later brooder and rearing - no lower then 5 (low light intensity causes a negative welfare effect without any positive production)
- egg production - 5 LUX min
- natural and AI breeding flocks greater then 10
why should you use a dusk till dawn method
- its a gradual change in light intensity
- this allows birds to wake up in a timly matter and not all at once
- prevents crowding at food and water stations
- prevents agression and bruising on carcass
what is CLUX
- chicken version of lux
- based on avian visual capacity
- should be used for coloured lighting
what is the effect of wavelength on growth and muscle yield
- disagreement in literature
- green/blue light stimulate growth early on in life
- some research shows no benefits at all
what does green light stimulate
- stimulates satellite differentiation, leading to an increased breast muscle yeild (in the first three days after hatch)