6. Laying hen behaviour and welfare Flashcards
ancestral roots and behaviour of the modern chicken
- “The” modern chicken is a descendent of Red Jungle Fowl (Galllus gallus), a ground dwelling species from west and central Asia that lives in small, stable, social groups.
- Red jungle fowl nest, forage and spend the majority of daylight hours on the ground, flying up to roost in trees, mainly at at night, in order to avoid predation.
- Domestic fowl (Gallus gallus domesticus) were domesticated over 8000 years ago
how have efficiencies in laying hen efficiency been realized?
confinement housing, nutrition, as well as genetic selection
pros and cons of confinement housing?
Confinement housing (battery cages) improved health, hygiene, efficiency but with significant behavioural costs to the hen
pros and cons of increased egg production from laying hens
- Earlier sexual maturity & greater egg production increases demand for calcium leading to osteoporosis, high risk for bone fractures
is nesting important for laying hens?
- Modern hen has retained ‘urge’ to nest
- Most hens prefer to lay in an enclosed space
- Most hens will perform a variety of ‘costly’ tasks to get to the nest box
-push through heavy doors
−Squeeze through narrow gaps
−Pass by a dominant hen
have most wild behaviours been retained in chickens?
yes
* Changes are quantitative rather than qualitative
* Thresholds may be altered
- Reduced fear, increased sociability, reduced anti- predator response
What Behaviour has Been Changed?
- Broodiness–incubation and care of chicks- has been heavily selected ”out”
- Feeding behaviour has become more efficient
> Laying hens “work less” for food
> But foraging behaviour still seems to be very important - Some abnormal behaviours have developed that we don’t fully understand
> Absence of foraging substrate is a risk for feather pecking….but it is not the whole story
Important Behaviors for Hens
- Nesting
- Perching
- Dust bathing
- Foraging
what is nesting and what is its basis? signs of frustration related to this?
Every time a hen lays an egg, it is preceded by searching, nest building and sitting on the nest
> endocrine basis - stimulated by ovulation
-Hens without a nest box are more active, take longer to settle, and show ‘stereotypic pacing’ during the hour before egg laying
-Hens given nests are more ‘settled’ prior to lay
what is perching? usefulness?
Hens perch in high places to avoid predators
* Hens prefer to rest/roost on perches
* Some data that hens work for access to perch
* It is well established that perching increases the strength of leg bones
what is dust bathing? how often and why does it occur?
-on litter, hens dust bathe every 2-3 days
-evolved for parasite removal, feather condition
-hens ‘sham’ dust bathe on wire floors
-hens dust bathe more quickly and for a longer period of time after going without litter
- ‘Build up’ of motivation
requirements for hen housing systems
-all housing systems to which hens are transitioned must support nesting, perching, and foraging behaviour
>must be transitioned by 2031, or else adhere to space requirements
>muse use enriched or non-cage housing system by 2036
big transition to what type of housing in hen agriculture?
cage free
pros and cons of conventional cages
-Promote good health and hygiene
-But space and behavior are greatly restricted
-And lack of exercise leads to weaker bones
what is a furnished cage? pros and cons?
-Include nest area, perches, scratch mat
-Provide the hygiene and health benefits of conventional cages
-Production comparable to conventional cages
-Perches and more space increase bone strength
- Furnishings intended to support behavior patterns important to hens
