Lecture 9 Flashcards
What is the Brambell Report?
“We accept that animals can experience emotions such as rage, fear, apprehension, frustration and pleasure.”
Freedom for fear and distress by ensuring conditions that avoid mental suffering
What is the definition of fear (state)?
An emotional response to the perception of immediate danger.
What is the definition of fearfulness (trait)?
A characteristic of an individual, susceptibility to fear.
How is fear experienced within different individuals?
-All individuals can experience fear
-Some individuals are more fearful than others
What are the two types of stress and what do they mean?
Eustress: good - motivates us (excitement exercise)
Distress: bad
* some stress is unavoidable
* manageable levels can increase resilience
What is anxiety?
A reaction to a potential threat
What is frustration?
An inability to achieve a desired goal. Can result in anger, annoyance, disappointment
What does fear and anxiety equal?
stressors
* primary emotions affecting animal welfare
* Responses: physiological and behavioural reactions - preparing the animal to respond
* Individuals vary in fearfulness: affected by genes & experience
What controls the stress response?
Sympathetic Nervous System / Neuroendocrine
What are the two main responses (axes) for the stress response?
*Sympathetic - Adrenal- Medullary (SAM)
- Fight or Flight: epinephrine, norepinephrine (happens immediately)
*Hypothalamic- Pituitary- Adrenal (HPA)
- CRH -> ACTH -> Glucocorticoid (eg. cortisol in humans and pigs, corticosterone in poultry and rodents)
What is the Sympathetic Adrenal Medullary (SAM)?
Rapid neural response:
* Adrenaline (from adrenal medulla)
* Noradrenaline (adrenal medulla and sympathetic nerves)
What are different effects of the sympathetic division on our bodies?
-Dilates pupil
-No effect on tear glands
-Weak stimulation of salivary flow
-Accelerates heart, constricts arterioles
-Dilates bronchi
-Inhibits stomach motility and secretion, inhibits pancreas and adrenals
-Inhibits intestinal motility
-Relaxes bladder
What are different effects of the parasympathetic division on our bodies?
-Constricts pupil
-Stimulates tear glands
-Strong stimulation of salivary flow
-Inhibits heart, dilates arterioles
-Constricts bronchi
-Stimulates stomach motility and secretion, stimulates pancreas
-Stimulates intestinal motility
-Contracts bladder
-Stimulates erection
What is fear and what is the function of fear?
- Fear is a negative emotion that is adaptive: fear responses protect the animal from injury.
- Function: animals in the wild benefit from fear. Increased awareness/vigilance, protection from/avoidance of predation
What are 3 behavioural responses to fear?
- Aggression
- Avoidance/escape
- Freezing
Stress response provides energy to cope
What is the difference for fear in domectic environments?
Fear is less adaptive in domestic environments
What are the two types of fear and what are some examples of issues they cause in animals?
- Acute fear: poultry piling, claw injuries, suffocation
- Chronic fear, anxiety: reduced growth, feed conversion reduced reproduction
How do intensive systems negatively effect stress levels in animals?
- Controlled, predictable environment - leads to overreaction
- Tried not to mix pigs or move pigs, however, created an overreaction when something did need to happen
What are some consenquences of fear (acute and chronic) in domestic animals?
- Energy wastage, reduced growth
- Delayed maturation
- Poor reproduction
- Handling stress, injury
- Injury, pain, weak immunity
- Increased death loss/disease susceptibility
What is the Novel Object Test (NOT)
- Behavioural test (best to do with neophobic animals (Fear of new things))
- Assesses fear and exploratory behaviour directed towards a ‘novel object’
- Animals tested singly or in groups
- ‘Novel object’ is introduced into the centre of the pen
- Less fearful animals are faster to approach and make contact
- Measurements: latency of approach (time) and number of contacts or number of individuals that makes contact
What is the Human Approach Test (HAT)?
- Behavioural test
- Measures level of fear associated with humans
- Handler enter the pen and remains stationary
- Less fearful animals are faster to approach and make contact - problems with defensiveness, aggression (attacks) or not caring (won’t approach)
- Measurements (time, objective)
What is the Novel Arena test (NAT)?
- AKA ‘Open Field Test’
- Measure fear and exploratory behaviour in a novel arena
- Animal enters the pen nd is observed over set time period
- Rodents’ entry into the centre squares indicates lack of fear (they like to be near wall)
- Increased defecation rate: increase rate under stress
How did the fear of people assessed in dairy cows affect them?
- Fear responses reduced with increased contact between stockperson and cows
- Introverted, confident stockpersons had calmer, more productive cows
- Presence of averisive handler (who hit or used a prod on cows over a 5-day period) increased the residual milk (milk not collected at milking) - she wasn’t delivering as much milk with aversive handler
What is vigilence behaviour in dairy cows?
- evolved for detection and avoidance of predators
- now used to measure fear
- Time spent ‘vigilant’ (head up/not eating)
- in novel location, in presenceof a dog, with aversive handler
What are other behavioural tests for measuring fear?
Tonic immobility in poultry
* ‘death feigning’ or ‘playing possum’
* parasympathetic response
* flipping chickens over (freeze)
Startle/freeze response
* time to resume activity following startle (e.g. loud noise)
Eye white in cattle
Elevated plus maze
* Exploration of open maze arms
What drug is the elevated plus maze used for?
Used in testing of anxiolytic (anxiety reducing) drugs. e.g. diazepam
What are some physiological measures of fear and stress?
- Respiration rate
- Heart rate (BPM)
- Epinephrine, norepinephrine (SAM)
- ACTH, Cortisol (HPA)
- CPK (CK): creatine kinase in blood - released from muscle following strain or bruising
- Blood lactate: physical exertion, product of anaerobic glycolysis
- Glucose: in blood, glycogen: in muscle or liver
What is cortisol and why can it be hard to interpret?
Most commonly used physiological measure of ‘welfare’.
Results are inconsistent because:
* levels are not constant: follows “diurnal rhythm”
* increases in response to excitement and stress
* different effects of acute vs chronic stress
* high individual variation - associated with temperament
* sampling process causes stress - affecting results
How does cortisol levels change with dehorning?
- dehorning with no anaesthetic caused high cortisol levels
- dehorning with anaesthetic caused same cortisol levels as just handling
How does stress (both long and short term) affect meat quality?
Acute stress:
* increase temperature, lower pH
* lighter colour, increased drip loss
* leads to PSE meat (pale, soft, exudative) in pork
Longer-term stress - fatigue
* depletes energy stores in muscle
* leads to DFD meat (dark, firm, dry) in cattle
How do we alleviate fear and stress?
Use both adapting the environment and changing the animal:
* environmental enrichment: reduce neophobia (fear of unusual things
* regular human interaction: positive handling
* selective breeding: cull “wild” or fearful animals