Mostly space
What is dust's source? Contributing factors? Control? effects?
Sources = feed, litter, feathers and dander
Factors = flight ability, behaviour (dust bathing, foraging)
control = ventilation rate, misting
detrimental effects = carrier of gases, vector of microbes, direct damage to the lung and respiratory tract
What are rods and cones
Rods and cones are photoreceptors found in retina
Rods associated with night vision
Cones associated with day vision
Rod free central retina indicates excellent day vision
What is lux based on and effective for
Based on humans visual ability
Effective for white light colour
What does darkness do to broilers
Darkness exposure reduced early growth but body weight may be equal or superior at older ages
darkness exposure improves feed efficiency
darkness exposure improves bird health
affects carcass yield = decrease in carcass yield, decrease in proportion of breast meat, increase in proportion of leg portions
darkness improves bird welfare - growth, mortality, skeletal health and mobility
increases activity and behavioural expression
What are david Frasers 3 circles of animal welfare
Basic health and functioning - growth production
Natural living - can birds express natural behaviours
Affective states - how do they feel
What are space requirements influenced by
Type of bird and eventual use
Management factor - cage vs floor, feed intake control
Environmental factors - environmental temp and season of the year
Quality of management
linear additivity of concurrent stressors
What are the two sources of light penetration for birds
Eye -> hypothalamus -> pituitary gland -> repro and body function
Skull -> pineal gland -> hypothalamus
What does green and blue light stimulate
Growth early in life
green = leads to increased breast muscle yield
blue = reduced stress and fear responses
how does darkness improve bird health
immune function - sleep is important for regeneration of tissues - specifically rem sleep
reasons for effect - reduced early growth using extended darkness, physiological changes during darkness
Mortality - sudden death syndrome, ascites, leg weakness = all growth associated diseases
better eye health
better diurnal rhythms
What are the 5 domains being adopted
Nutrition
Environment
Health
Behaviour
Mental domain
What are the effects of inadequate space
Decreased performance
Reduced uniformity
Increased mortality
Increased carcass defects
Increased condemnations at processing
Decreased behavioural expression
What does light intensity do? And what does Low vs high intensity change?
Manipulated to influence bird behaviour
positive relation ship between light intensity and bird activity
Low = Reduces cannibalism, reduced mortality, reduce feed wastage, decrease bruising
High = eating and drinking, mating activity
What is the correlation between emotional stress and production
Chickens selected for low fear of humans had higher body weights and laid larger eggs
birds exposed to fearful situations: reduction in growth and increased feather pecking
What is welfare
Giving the animal a good life
What does cortisol do
Measures acute stress primarily but sometimes used for chronic stress
follows a diurnal rhythm
What are the 4 concepts of establishing space requirements
Economical - space required to achieve maximum economic return
Biological - space required to achieve maximum productivity = growth, egg production, health, mortality, body and feather condition
affective state - prevention of suffering due to pain, fear and frustration as well allowing birds to experience positive states
Natural living - Allow birds to perform basic body movements and comfort behaviour as well as unrestricted opportunities for nesting, dustbathing, pecking, and scratching
What does low light intensity increase and reduce - good and bad?
increase Resting and reduce comfort behaviours
Increases breast blisters and footpad lesions due to more resting
Increases eye abnormalities and cause blindness
helps control cannibalism and bullying in turkeys
What are the different behaviours in poultry? (hint 5)
Active - walking, running, standing, resting
Nutritive - feeding and drinking
comfort - preening, dustbathing, leg and wing stretching
exploratory - foraging
abnormal - feather pecking, cannibalism, stereotypies (animals trying to cope with a lack of stimulation)
What 3 areas did ruth harrisons animal machines book highlight
Veal crates, sow gestation crates, and conventional cages
What are input measures vs outcome measures
input = how big is the cages, is the flooring appropriate - Easy to measure
Outcome = are there sores on their feet when they're in cages
What are some general eye facts about poultry
Large eye size
Highly developed sense of vision
extended spectral sensitivity - including UV
Excellent ability to differentiate colour
What should light intensity be at?
Early brooding - broilers at least 20 lux, turkeys 40-60 lux
Later brooding and rearing - no lower than 5 lux
egg production - 5 lux min
natural and AI breeding flocks = >10 lux
What are the three rules to remember about repro and photoperiod
Never increase photoperiod length during brooding and rearing
Minimum of 12 hours of light is required for maximum stimulation
never decrease photoperiod length during egg production
What are the 5 freedoms
Freedom from hunger and thirst
Freedom from discomfort
Freedom from pain, injury and disease
Freedom to express (most) normal behaviours
Freedom from fear and distress
What are the different types of welfare issues
behaviour - fear reactions, lack of stimulus, health can lead to limited behaviour expression