Lecture 13 - Physiology of Distress in Animals Flashcards
Anthropocentric vs anthropomorphic
Anthropocentric = man has dominion
Anthropomorphic = man has no dominion
Green benefits of increasing animal welfare
Increased efficiency, reduces CO2 footprint
How many kg CO2 are formed for 1kg beef
25kg
What are the three stress models
Environmental, psychological, biological
What is the environmental stress model
Event based (life is a stressor)
Non parametric scale of measurement (e.g. social readjustment rating scale, job loss=20)
What is the psychological stress model
Perception based
Perceived stress scale
“Rank pain from 1-10”
What is the biological stress model
Hypothalmic-pituitary-adrenal
Alarm->resistance->fatigue
What did Dr Hans Selye do
Classical stress theory (rat adrenals)
Describe HPA briefly
Stressor activates hypothalamus which activates pituitary which activates adrenals
What is the steady state stress model
Alarm -> resistance -> fatigue
Four lobes of brain?
Frontal, parietal, occipital, temporal
Is fear psychological or measurable?
Both? Now can measure through MRI
What is the site in the brain for fear
Amygdala
Are pain and fear seperate?
Can be
But can also have one without the other
Four types of fear
Innate (spider)
Novelty (cave)
Experience
Observed in others
What are the affective states for measuring distress
Cortisol, behaviour, aversion, preference, normal/abnormal, HR
How do we measure cortisol level?
Salivary (horse) or fecal
Orthodontic dental sink (tooth cap absorbing cortisol)
Three non-invasive measurements of stress
Salivary cortisol, behavioural observations, infrared thermography
Are physical or psychological stressors more stressful?
Psychological
Treatment that most increased plasma corticoid?
Transport (1 week)
What happens when observing under IRT an animal in distress
Drop in temperature of inner eye
How does IRT indicate best show jumpers in competition
Lower eye temperature before/during competition = better performance
Can also indicate when horse is ready to compete again
How does change in temperature work (acute vs chronic stress)
Acute will lead to drop in temperature, once hypothalamus registers stressor it increases temperature to produce energy to counter it
Chronic stress leads to HPA fatigue which leads to decrease in temperature
Why does the temperature reaction to chronic stress cause problem?
Decrease in temperature, so people might not think animal is stressed (e.g. over long transport)
IRT difference between efficient and non-efficient pig
Non-efficient is bright red, losing lots of energy
How do infrared and salivary cortisol change over transport
Both (cortisol and temperature) increase
Effect of long term transport on temp
Decrease because energy is all expended during transport (HPA fatigue)
Anion gap measurement over 8h transport?
Large negative ion gap
Is IRT good for early disease detection
Most efficient out of any
How do you increase accuracy of the measurement
Combine two non-invasive measurements (e.g. IRT and Behaviour fidget)
Why should we early detect?
Lower treatment cost, better treatment efficacy, reduced risk of antibiotic restistance, improved animal performance/welfare/food safety
What physiological impacts for transportations tress have
Protein degradation, dehydration, ion imbalance
Benefits of nutritional therapy?
Decreases stress (decreased cortisol, better carcass yield, lower infrared temperature)
How does environment lighting affect stress?
Natural lighting = lower basal cortisol, lower response to transport, better lean yield
How does environmental enrichment improve welfare
Decreases aggression
How do we keep stress levels down in bison before death
Use of mobile abattoir = more tender meat, less bruising
Why do we care about AW
Sentient species, pragmatic, economic, diet, environmental
Good news about AW science?
Science/precision farming used to improve welfare
