ANIMAL WELFARE (Aggressive Behaviour) Flashcards
Aggression:
-a physical act by one individual with the actual or potential result of harming, limiting or depriving the ‘fitness’ of another
Agonistic behaviours:
-broader term
-includes all forms of behaviours associated with conflict between animals
>including both aggression and submission
Ex. threats, displays, retreats, immobilization
Aggressiveness:
-personality trait shaped by genotype and early experience
-modulated according to psychological, physical and physiological characteristics
*costly behaviour: important for animals to learn or give up soon (aware when the cost would be too much for the reward)
Psychological characteristics:
-win-loss ratio
Physical characteristics:
-presence of horns, antlers, etc.
Physiological characteristics;
-hormonal status
-health status
Animals that are more successful with aggressive behaviour:
-will be more likely to continue to do the behaviour
types of aggressive behaviours
- Offensive
- Defensive
- Predatory
- Organic origin
- Mock fighting
offensive
-territorial
-sex related
-instrumental aggression
defensive
-fear-induced
-maternal
Offensive behaviour:
-individual trying to gain access to a specific resource
Territorial behaviour:
-occurs in an area in which the animal has established itself
-40-60% of cases
Sex related behaviour:
-stimulated by the proximity of 2 males not familiar with each other
-elicited by the same stimuli that elicit sexual responses
Instrumental aggression behaviour:
-learned response (reinforced)
Ex. fight between dogs: shown behaviour due to dominance, but it has been reinforced by performing the behaviour and will do it more often
Defensive behaviour:
-avoidance of an external intrusion
Fear-induced behaviour:
-characteristic of confined or cornered animals that feel threatened
-preceded by escape movements
Maternal behaviour:
-elicited by the proximity of some agent that is threatening to a female’s young
Predatory behaviour:
-inhibited by a hungry individual in the presence of a prey item
Organic origin behaviour:
-irritable state elicited by a broad range of health issues
Ex. stress/frustration, pain, brain tumours, rabies
Mock fighting:
-a feature of social reactivity
-variant of play behaviour
-no harm is caused, but it’s a good experience to refine their motor skills
Can tell behaviours apart based on:
-origin of behaviour OR the body signals that an animal displays
Offensive aggression body signals:
-tail bristled, raised and stiff
-legs stiff
-ears forward
-nose wrinkled
-lips curled
-teeth visible
-body leaning forward
Defensive aggression body signals:
-tail tucked and stiff
-ears back
-nose wrinkled
-lips slightly curled
-teeth may be visible
-body lowered
To differentiate aggressions:
-posture
-circumstances
-who is the aggression directed to
Posture:
-is not voluntary
-triggered by the neurons activated with each type of aggressive behaviour
Circumstances when:
-approached
-food is around
-you want to touch it
Who is the aggression directed to:
-owners
-one individual in particular
-other dogs
Aggressive behaviours in dogs, problem for the dog
-euthanasia
-abandonment
Aggressive behaviours in dogs, problem for the humans:
-2-5 million people bitten per year
>1 million requiring hospitalization
-280deaths in 15years
-particularly in children (40%)
*in most cases dog had owners and there was no obvious triggering cause
Destructiveness:
-can also be considered a redirected aggressive behaviour
-huge proportion of why animals end up in shelter
Causes of aggression in farm species:
-mixing of unfamiliar animals
-competition over food
-spatial factors and overcrowding
-frustration, fear, pain, boredom
Pigs aggression:
-slash with tusks at opponents neck and shoulders
-bites directed towards shoulder, neck, front legs and ears
-some head knocks against opponent
-no kicking
Cattle aggression:
-horns and head to butt neck, shoulder, flank and buttocks
-kick with hind legs to the side
-no biting
Sheep aggression:
-butt with head, often back up and charge
-clashing head on
-do not kick or bite
Goats aggression:
-similar to sheep
-butt heads
-rear on hind legs and clash heads on downward thrust
-do not kick or bite
Horses aggression:
-bites directed towards neck, shoulders, flank and legs
-kick with hind legs
-may defend front legs from bites by kneeling
Chickens aggression:
-face each other with raised hackles and direct peak at head and body
-scratch with feet and spurs as they fly towards opponent
Consequences of aggression:
-physical injury
-physiological effects
Physical injury:
-to humans and conspecifics
1. Lacerations
2. Injuries
Lacerations (physical injury)
-provide avenue for infections
-skin damage and bruising results in reduced revenue
-leads to increased cut outs and downgrading of meat products
Injuries (physical injury):
-most common reason for culling bulls used in community pasture systems is lameness
>often due to injuries suffered during male-male fighting
Physiological effects:
-natural activation of HPA axis, which may lead to immunosuppression
-can be lethal in pigs with a genetic defect or cause reductions in carcass value
-fighting depletes glycogen stores in muscles, which results in high pH and dark cutters
Physiological effects: pigs with genetic defect:
-can be lethal
-sudden death
*Porcine Stress Syndrome
Reduction in carcass value: PSE
-pale
-soft
-exudative
Controlling aggression:
-make accurate diagnostic on the REASON of aggressive behaviour
>offensive, defensive, organic source….
Controlling aggression examples:
-castration
-drugs
-behavioural training
-increase serotonin
-environmental design
-provide sufficient food
-avoid mixing
castration:
-for offensive aggressions
-doesn’t work in females
-may need additional treatment
Drugs:
-useful while the drug is active, so you can implement other measures
Behavioural training:
-change of dominance rank, socialization
-flooding/habituation
Increase serotonin:
-through diet, exercise and drugs
Castration, dehorning, tail docking, teeth clipping:
-does NOT remove the CAUSE of the aggression
-provides long term benefits
-most are under close examination
Environmental design:
-adequate space provision
-allow animals to remove themselves from the situation
