Lecture 7 Flashcards
What are the 5 freedoms?
- Freedom from Hunger and Thirst - by ready access to fresh water and a diet to maintain full health and vigour
- Freedom from Discomfort - by providing an appropriate environment
including shelter and a comfortable resting area - Freedom from Pain, Injury or Disease - by prevention or rapid diagnosis and
treatment - Freedom to Express Normal Behaviour - by providing sufficient space, proper facilities and company of the animal’s own kind
- Freedom from Fear and Distress - by ensuring conditions and treatment
which avoid mental suffering
What is freedom from hunger?
“hunger and thirst are the two most basic, primitive and unremitting of all motivating forces” (Webster, 1995)
Failure to eat/drink leads to death
Lack of essential nutrients leads to illness, and death
What does mild deprivation do?
mild deprivation has little effect in fact, feed restriction in rodents is well known to
increase life-span
What does ad lib feeding do?
ad lib feeding of some species can lead to
disease and poor reproductive performance
eg. Sows, broiler chickens, rodents
Increasing awareness of obesity as a problem- in humans, dogs, cats, parrots
Is hunger (or thirst) always indicative of poor welfare?
depends on the severity of the hunger, if the animal’s body condition is decreasing then it is an indication of poor welfare. an animal should always have access to water and should not be thirsty
Is not some degree of hunger necessary to regulate feed intake?
At what point should we consider hunger a welfare problem?
What is hunger?
the state in which an animal is stimulated to eat
What is malnourished?
insufficient quality lack of nutrients, or incorrectly balanced
vitamin A deficiency
What is Under nourished?
insufficient quantity
poor body condition
What is satiety?
feedback systems that inhibit feeding
What is the model of feeding behaviour?
Hunger is the motivation behind feeding behaviour
Appetitive phase: increasing hunger,
foraging behaviour (increased activity and increased aggression)
Consummatory phase: feeding (negative feedback loop)
What does hunger result in?
Hunger results in increased feeding motivation, expressed as:
-Increased activity (hunting/foraging)
-Increased aggression- feed competitor resource guarding
-Redirected oral behaviours:
–Increased drinking (polydipsia)
–Stereotypies, Coprophagia (eating poop), Geophagia (eating dirt)
Has selection of species for high growth increased hunger when limit fed?
Has selection of species for high growth increased hunger when limit fed?
May depend on species and gut storage….
-Pigs: limited gut storage, bouts of absorption
-Ruminants: large storage, continuous absorption
-Chickens: moderate storage, continuous absorption
Reflected in maximum transport times…
Recommended maximum transport times in Canada?
Monogastrics (pigs, equine) - 28 h
Ruminants (cattle, sheep, goats) - 36 h
Poultry - 28 h
Chicks (newly hatched) - 72 h (yolk sac)
Calves - 12 h
- Max transport times in other countries are generally much shorter. WHY?
Have more slaughter plants thus don’t have to travel as far
What Situations cause acute* hunger/thirst?
Feed system breakdown/outage
Transport- feed restriction
–long transports- assembly yards
Marketing- auction or assembly yards
Skip a day feeding- sows, broiler breeders
Forced moulting – laying hens
*Acute: Resulting from an accident (quickly rectified), or deliberate management decision
What Situations result in chronic hunger?
Situations resulting in chronic hunger are more common and problematic:
Long term restriction of feed intake
Poor pasture or range conditions
—Starvation during drought
—Overstocking/overgrazing
Limit feeding of breeding animals
–Sows, broiler breeders
Subordinate animals, when feed is limited
Call SPCA if you see this
Problems related to hunger affect?
1) Behaviour (compensation/coping strategies)
2) Physiology (body condition, coat condition, healing)
3) Illness (morbidity, mortality)
Observational measures: feed intake, rate of eating, time spent feeding.
Operant measures: willingness to work for
food (lever presses, weighted push gate)
How hard will pigs work to obtain food?
Operant conditioning:
—Fixed ratio (10 presses per reward)
—Progressive ratio (increasing number
of presses needed for each reward)
Pigs fed once per day at 1.0, 0.8, 0.6 and 0.4 of ad libitum
Tested at 1, 5 and 22 hr after feeding
Conclusions: On levels similar to that fed
breeding animals (60% of ad lib), pigs reached maximum response rate within 5 hours of feeding
Breeding pigs are hungry approx 19 hours/day
What are Stereotypies?
Animals in confinement exhibit two general types of stereotypies
Oral stereotypies
–associated with hunger or feed quality
Movement stereotypies
–associated with restrictive housing
Can increasing feed volume with fibre
reduce stereotypies?
Dry sows were fed diets varying in volume
and fibre content:
–Restricted fed (2kg conventional diet)
–Restricted plus fibre (2.3kg)
–Ad lib fibre
Measured time spent eating and
performing oral behaviours
Fibre increased feeding time and reduced
oral behaviours/stereotypies in sows
Providing high fibre diets has also been
shown to reduce:
–Cribbing and wood chewing in horses
–Feather pecking in poultry
–Tail biting in pigs
–Tongue rolling in cattle
Chronic Hunger: Starvation
Some extensive production systems experience seasonal weight loss, either annually or during dry years
—Extensive grazing systems
How much weight loss can be tolerated?
At what point is massive culling called for?
Examples:
–Australian outback
–Blizzards
–Hay shortages
What is Thirst or water restriction?
Defined as insufficient water to meet physiological requirements
Problems of water quality and quantity
–Eg High sulfur levels in sloughs
Basic management- but a common problem in both intensive and extensive systems
How do we assess comfort?
Preference tests:
– What do they want?
– How much do they want it?
– Do they really need it?
‘Ask’ the animal…
-Preference tests – animals can ‘vote with
their feet’
-Operant conditioning- learn a task, ‘what
will they work for?’
-Observe their behaviour…
What happened on the hen flooring test?
Hens were offered 2 options at once; time spent on each was recorded
Order of preference:
– hexagonal wire netting (first)
– heavy-gauge wire mesh
– conventional wire mesh
– perforated sheet metal (last)
The one they chose was really bad on their feet and legs and caused problems
Flooring for pigs – do they prefer straw
or concrete?
sometimes straw bedding was preferred
sometimes concrete
this was dependent on the temperature
Real Preferences?
Early preference tests were too simple
Preferences vary with conditions Therefore:
-Consider multiple factors/ perform multiple studies (eg. seasonal differences)
-Consider the previous experience of subjects (prefer what is familiar)
How do we determine the strength of a preference?
Test ‘willingness to pay’
Using Operant test (trained on button/lever), or Physical effort (push gate)
