ANBI 411.3 Lecture Notes - Lecture 6: Operant Conditioning, Outdoor Water-Use Restriction, Malnutrition
20 Jun 2018
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Lecture 6: Hunger, Thirst and Malnutrition Animal Comfort
The five freedoms:
1. Freedom from hunger and thirst- by ready access to fresh water and a diet to maintain
full health and vigor
2. Freedom from discomfort- by providing an appropriate environment including shelter
and a comfortable resting area
3. Freedom from pain, injury or disease- by prevention or rapid diagnosis and treatment
4. Freedom to express normal behavior- by providing sufficient space, proper facilities and
company of the animal’s own kind
5. Freedom from fear and distress- by ensuring conditions and treatment which avoid
mental suffering
Freedom from hunger
- Hunger and thirst are the two most basic, primitive and unremitting of all motivating
forces
- One of the most basic behaviors
- Failure to eat/drink leads to death
- Lack of essential nutrients leads to illness and death (malnutrition state= chronic
hunger)
mild deprivation has little effect
- In fact, feed restriction in rodents is well known to increase life-span
Ad lib feeding of some species can lead to disease and poor reproductive performance
- Examples: sows, boiler chickens, rodents
- Increasing awareness of obesity as a problem- in humans and dogs
Is hunger (or thirst) always indicative of poor welfare?
- Is not some degree of hunger necessary to regulate feed intake?
- At what point should we consider hunger a welfare problem
Hunger: the state in which an animal is stimulated to eat, is a subjective feeling
Malnourished: insufficient quality- lack of nutrients or incorrectly balanced
Undernourished: insufficient quantity
Satiety: feedback systems that inhibit feeding
Hunger is the motivation behind feeding behavior
There are appetitive and consummatory phases
hunger results in increased feeding motivation, expressed as:
- Increased activity (foraging)
- Increased aggression
- Redirected oral behavior
oIncreased drinking
oStereotypies, coprophagia, geophagia
oExample: bar biting
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find more resources at oneclass.com
Hunger in different species
- Has selecting species for high growth increased hunger when limit fed?
- Is hunger a greater/ or less significant issue with opportunistic feeders?
- Digestive system are different in different species, need to know this because it effects
how they feel hunger
oPigs: limited gut storage, bouts of absorption
oRuminants: large storage, continuous absorption
oChickens: moderate storage, continuous absorption
- Reflected in maximum transport times
Acute hunger and thirst
- Situations causing acute hunger/thirst:
oFeeding system breakdown
oTransport- feed restriction, long transports
oMarketing- auction or assembly
oForced moulting
- Acute: result of accident (quickly rectified), or deliberate management decision
- Re-alimentation during long transports
oIs it more humane to keep animals on truck, or to affload for feed and water?
Chronic hunger
- Situations resulting in chronic hunger are more problematic:
oLong term restriction of feed intake
oPoor pasture or range conditions
Starvation during drought
Overstocking/ overgrazing
oLimit feeding of breeding animals
Sows, broiler breeders
oSubordinate animals, when feed is limited
Measuring hunger:
- Problems related to hunger affect (measures hunger by looking at these things):
1. Behavior (compensate/coping)
2. Physiology (body score, coat condition, healing)
3. Illness (morbidity, mortality)
- Observational measures: feed intake, rate of eating, time spent feeding, body condition
- Operant measures: willingness to work for food (lever presses, weighted push gate)
Stereotypies
- Several species exhibit two general types of stereotypies
oOral stereotypies; often associated with hunger or feed quality
oMovement stereotypies: often associated with restrictive housing
- Can increased feed volume with fiber reduce stereotypies?
oLots of research shows that if you increase fiber content the animals will
decrease sterotypies activity
find more resources at oneclass.com
find more resources at oneclass.com
