Fear and distress Flashcards
bramble report findings and results
-we accept that animals can experience emotions such as rage, fear, apprehension, frustration and pleasure
-turned into the five freedoms
fear
(state) and emotional response to the perception of immediate danger
fearfulness
(trait) characteristic of an individual, susceptibility to fear
who experiences fear
all individuals can experience it but some may be more fearful then others
stress
not all stress is bad
eustress
good stress (going to the gym)
distress
-bad (thunderstorm)
-but manageable levels can increase resilience
anxiety
reaction to a potential threat (anticipation)
frustration
-inability to achieve a desired goal
-can result in anger, annoyance, disappointment
-ie. rodent digging a hole that keeps filling
who was stress first studied by
-Walter cannon, early 1900s
-came up with the flight and fight response
fear and anxiety
=stressor
-primary emotion affecting animal welfare
fear and anxiety responses
-physiological and behavioural reactions-> preparing the animals to respond
-individuals vary in fearfulness: affected by genes and experiences
fear and stress physiology
-the stress response: sympathetic nervous system/neuroendocrine
-two main responses (axes):
-sympathetic-adrenal medullary (SAM)(fight or flight:epi, norepi)
-hypothalamic-pituitary-adrenal (HPA) (CRH-ACTH-glucocorticoids(eg cortisol))
HPA-axis
-stressor (physical/emotional)
-hypothalamus<–>brain stem
CRH
-anterior pituitary
ACTH
-adrenal gland (cortex)
GCs cortisol (glucocorticoids)
-target organs and systems
-neg feedback loop; reduction in CRH and ACTH
-pos feedback loop; increase in CRH and ACTH
SAM-axis
-stressor (physical/emotional)
-brain stem<–>hypothalamus
-spinal cord
sympathetic neurons
-adrenal cortex (medulla)
adrenaline
-target organs and tissues
acute stress main hormone
adrenaline
chronic stress hormones
cortisol
SAM is a rapid neural response what hormones and where do they come form this
-adrenaline from the adrenal medulla
-noradrenaline from the adrenal medulla and sympathetic nervous system
things seen from the sympathetic nervous system
-dilate pupils
-no effect on tear glands
-weak stimulation of salivary flow
-accelerated heart, constricts arterioles
-dilates bronchi
-inhibits stomach mobility and secretion, inhibits pancreas and adrenals
-inhibits intestinal mobility
-relaxes bladder
-stimulates ejaculation
things seen form the parasympathetic nervous system
-constricts pupils
-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 the bladder
-stimulates an erection
function of fear
-fear is a negative emotion that is adaptive: fear responses protect the animal form injury
-function: animals in the wild benefit from fear
-increased awareness/vigilance, protection from/avoidance of predation
behavioural responses to fear include
-aggression
-avoidance/escape
-freezing
-these responses provide energy to cope
fear in a domestic environment
is less adaptive ie. wild chickens fly to trees, barn go to a corner and pile
acute fear in domestic animals (example)
-poultry piling, claw injuries, suffocation
chronic fear in domestic animals
reduced growth, feed conversion
different kinds of things that cause fear in domestic animals
-novelty: changes in environment
-human interaction: lack of regular handling
-domestication: most are calm, some are fearful
-intensive systems: controlled, predictable environment, leads to overreaction
fear (acute and chronic) consequences in domestic animals
-energy wastage, reduced growth
-delayed maturation
-poor reproduction
-handling stress, injury
-injury, pain, weak immunity
-increased death loss/disease susceptibility
measuring fear: novel object test (NOT)
-behavioural test
-assesses fear and exploratory behaviour directed towards “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
-measures time, objective, if animal is not able to move may not work
measuring fear: human approach test (HAT)
-behavioural test
-measures level of feat associated with humans
-handler enters the pen and remains stationary
-less fearful animals are faster to approach and make contact
-measurements? time, objective, movement
measuring fear: novel arena test (NAT)
-open field test
-measures fear and exploratory behaviour in a novel area
-animal enters the pen and is observed over set time period
-rodents’ entry into the centre squared indicates lack of fear
-increased defecation rate?
fear and human contact in dairy cattle
-response reduced with increased contact between stock person and cows
-introverted, confident stockpersons had calmer, more productive cows
-the presence of an aversive handler (who hit or used a prod on cows over a 5-day period) increased the residual milk (milk not collected at milking)
vigilance behaviour (dairy cows)
-evolved for detection and avoidance of predators
-now used as a measure of fear
-time spent ‘vigilant’ (head up/not eating)
-in novel or familiar location
-in presence of dog or unfamiliar person
-in the presence of gentle or aversive handler
-how ever in some cases could be curiosity
measuring fear: tonic immobility in poultry
-‘death feigning or ‘playing possum’
-parasympathetic response
measure of fear: startle/freeze responce
-time to resume activity following startle
-e.g. loud noise
measuring fear: eye white in cattle
measuring the amount of white in the ox’s eyes
measuring fear: elevated plus maze
-exploration of open maze arms
-less stressed in solid walls then transparent
measure of fear: chute test in cattle
measure how hard the cow tries to get out
physiological measures of fear and stress
-respiration rate
-heart rate (BPM); heart rate variability (HRV)
-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
cortisol
-the “stress hormone”
-most commonly used physiological measure of “welfare” but results are inconsistent and herd to interpret
why can using cortisol levels for measures of welfare be hard to interpret
-levels are not consistent: follows diurnal rhythm
-increased in responce to excitement AND stress
-different effects of acute vs chronic stress
-high individual variation associated with temperament
-sampling processes cause stress affecting results
-feedback mechanism
stress and meat quality
affected by pre-slaughter stress and handing
acute stress and meat quality
-increased temperature, lower pH
-lighter colour, increased drip loss
-lead to PSE meat (pale, soft, exudative)
long term stress and meat quality
-fatigue
-depletes energy stores in muscle
-leads to DFD (dark, firm, dry)
what is a common dilemma for alleviation of stress
-do we adapt the environment to suit the animal? ie low-stress housing and management
-or do we change the animal to suit the environment (breeding, selection and culling)
-ideally use multiple approaches:
-environmental enrichment: reduce neophobia
-regular human interaction/positive handling
-selective breeding- cull ‘wild’ or fearful animals
