6 aug Besök på Blue Hors

Körde från Göteborg strax efter nio på morgonen, bron över Öresund, bron över Stora Bält, bron över Lilla Bält, Vejle, rätt väg hela tiden, insåg att vi skulle hinna precis till kl fyra. Tills vi körde över vägen vi skulle vika in på, snopet, ingen avtagsväg. Av i nästa by, på småvägar tillbaka, stannde och frågade, vidare på ändå mindre vägar, rätt till slut, en kvart försenade. Men ändå. 

Stora grå byggnader i sten och betong, praktiskt och imponerande, kanske inte vackert. Dock boxväggar i trä och blommor i fyrkantiga grå lådor. Stallchefen visade oss runt. Kylbad demonstrerades av två tjejer, som stod till knäna i strömmande vatten, iskallt enligt stallchefen, men inte enligt tjejernas minspel, de hade kul. 20 minuter normal längd för häst efter arbete. 

Ett större ridhus med dekorationer av stiliserade träd och mahognyliknande sargtoppar, ett mindre, båda med kapillärbevattning underifrån, fibersand. I annat stall ett mindre ridhus med sarg av plastbrädor, antagligen för rastning och visning av unghingstar.

Hans Selye - stress and pathology, hormones. HPA-axis, a non-specific defense mechanism of the body, chronic or repeated stress with ulceration etc.

Allostasis vs homeostasis: allostasis is stability through change. Brain can adjust set-points

Many definitions of stress, prolonged and severe in situations where normal processes have been stretched beyond normal adaptive range - only pne definition of many, which can be very diverse.

Robert Sapolsky - focus on the biological effect of stress, author of Why zebras don't get ulcers, video Portrait of a killer

Stressor - an event, internal or external to the body involving a real or potential threat to the maintenance of the honeostasis/inner balance of the body. Ex predator, aggression, parasites, extreme weather

Stress response - all behavioural and/or physical response factors

Behaviour to facilitate adaptive responses to overcome stressor by orientation, action, go back to normal behaviour

Change in sympathetic ns produce noradrenaline, adrenaline from spinal cord resp adrenals, same time from hypothalamus to pituitary gland produce ACTH and opioid over to adrenals to produce cortisol

Whole system shuts down by negative feedback, limits the possible negative consequences of not needed effects

Dualism of stress, breakdown of adaptive mechanisms. Adaptive nature and potential maladaptive consequences

Long term conditions increase cortisol, adrenal weight, infections, gastric ulcers, heart disease, decrese of learning ability, immune system

Stressor properties - duration/acute, intermittent, longterm, how experience it/how the stressor is percieved/by learning, earlier experience, frequency, level of novelty, intensity, predictability

Stress, to do - mobilise energy, dump energy into bloodstream, deliver to muscles ASAP, sharpen senses

 

 

Rupert Palme, hormones as indicators of equine stress: assessment of APA-axis responses in horse

 

Glucocorticoids in samples from blood, urine, hair, saliva, faeces. Faeces very easy, give the same measureability, only the freezer is the limit

Secretion - hypothalamus, pituitary, adrenocortex, glucocorticoids binding to proteins and metabolistic process, in horses percentual cortisol level between faeces and urine about the same

Metabolism of cortisol complex, different assocoations in molecules, varies a lot between species. Cortisol itselt in very small amounts, cortisol metabolites is used for measuring. Extract, centrifuge

Faecal samples has less variation in cortisol metabolites

Change in cortisol release in transported sport horses, peaks at three hours, again almost as much in twelve hours

In naive horses during repeated transport, cortisol decreases over four days of repetition

Initial riding of three-year-olds, cortisol peaks after training session

Samples from rider's saliva before and after jumping a course, males higher and also higher after course (in one test females lower after)

 

 

Strengths and limitations of measuring HR, HRV and cortisol, Visser and Heleski

 

Stress is necessary for learning an effective behaviour

Assessment of stress best both behaviour and physiological measurements

Primary stress response, sympatho-adrenomedullary

Autonomic ns, sympathetic/fight and flight and parasympathetic/rest and digest, HRV balances

Diseases, psycological, environmental, individual

Baseline difference in cortisol increases with age and training, also higher in the morning, 5-15 mins after training, 20 mins after clipping. Returned to baseline after 1 hour. Chronically stressed leads to cortisol exhaustion and low levels, as in housing in pairs had higher levels than individual housing (?)

What is high, too much? When becomes negative? Pathological? 

 

 

Salivary cortisol response of sports horses during a four days national show and the correlation to reactions in temperament test, Munk Andersen et al

 

What makes a champion? Physical ability, ability of the mind, coping with stress?

Differ in horses and humans, cortisol levels with performance. 

Test in familiar object, bridge test, unfamiliar person in box etc on horses selected for national show, sj and dressage. Cortisol levels at home and at show

Cortisol level after test at home lower than at the show, did not return to home baseline levels at the show, so no habituation

 

The psysiological difference between crib-biter and control horses in a standadised ACTH challenge test, Freymond et al

 

Origin, chronic stress, conflict, frustration especially early in life in combination with genetic disposition, may be a coping mechanism

Glucocosteroids increases 

Adenocorticotropic hormone/ACTH, challenge test

May be less flexible when facing stress, adrenal rssponse should be lower

Test showed no difference between crib-biters and non crib-biters in HR, but in saliva cortisol, especially the crib-biters that did not crib-bite during the test. During and after bouts of crib-biting, cortisol levels and HR were lower - might help them to cope?

 

 

Can equestrian professionals recognise signs of stress in the ridden horse? Hall et al

 

Trying to develop a form for scoring parameters in the behaviour of the ridden horse. How do we know if a HR etc shows a negative situation?

Identify behaviour signs in the ridden horse, not physically challenging exercises.  Positions of head, tail, nasal plane, neck carriage, head movement, ear position, mouth, salivary, sounds

Only significant correlations in head/neck positions

Low head carriage increased salivary cortisol, but was preferred, could be an idea that the horse was working harder

Duration nasal plane behind vertical and higher eye temperature correlated

Duration nasal plane in front of vertical and low eye temperature correlated

Increase salivary cortisol and tail svishing

Professionals liked nose behind vertical, instructors had milder view than riders and vets

 

 

Analysis of heart rate variability compared to a composite pain scale as indicated of post castration pain, Stucke et al

 

Significant increases in pain related behaviour from only anaesthesia three hours after castration and low frequency peak, same time in HRV. Significant decrease in frequency in horses who also got local anaesthesia in the spermatic cord. Significant increase in HF power/cardiac vagal tone/parasymp, contrast to previous studies

Conclusion autonomus ns to pain stimulus vary as a function of localisation. Vagal activation/HF increased after castration. Composite pain scale useful tool.

First day after castr crucial for pain control.

 

 

Monitoring acute equine visceral pain, scale of construction af equus compass and equus composite pain scale and facial pain expression scale, van Loon and van Dierendonck

 

Visual analogue scale shown. Composite numeric rating scale, composite orthopaedic pain scale, facial action coding system in humans, grimace scale for lab animals

Stiffly backward ears, etc etc.

 

 

Responses of horses to sudden object and sudden noise in relation to direction and distance of the stimulus, Pierard and Geers

 

Umbrella falling down, umbrella pulled up, sudden noise, distance to activity

Almost no influence of distance or direction

Noise, limited difference in locomotion. Mimimum influence of direction and distance

Police horses, with extensive habituation training, might not be ideal reference for other horses

 

 

Detection of ECG artefacts in horses, comparison between textile and standard electrodes, Lanata et al

 

Smart textiles, noise of ECG signal mainly refers to movement artefacts, textile electrodes showed better performance

 

 

Stress, dopamine and the horse's brain: implications for learning and training, McBride

 

Basal ganglia-neuroanatomy and circuitry, functional heterogenity of the striatum, different stages of learning, stress and the neurophysiology of the striatum, implication for learning, other facts

Basal ganglia, cortical and sub-cortical

Cortex to striatum, the main center of the basal ganglia, to internal globus pallidus and external globus pallidus, to thalamus, to the cortex. Indirect through external gp, direct throug internal gp. Mid-brain and striatum, cortex asking the striatum of action or not.

Striatum has caudate, putamen and nucleus accumbens, each are responsible for different types of learning; nucleus/pavlovian, caudate/action outcome, putamen/habit formation/stimulus response

Pavlovian or aquisition, first level of learning. Habit formati, stop monitor your actions. Action/outcome, try different if doesn't work.

Operant, what did I just hear etc/sensory. What did I just do/motor efferent

Sensory information to striatum. Motor cortex to striatum. Reward releases dopamine from the mid-brain, but only if reward is unexpected or greater than usual. Function of dopamine? Sensory information is now linked. When conditioned, the stimulus creates the dopamine production sent to basal ganglia.

Stress and the striatum, in rodents upregulation and downregulation of dopamine systems, hyper-motivation phenotype or opposite, stereopathy or learned helplessness

Similar results in horses, same upregulation but also a downregulation. Hypermotivated and/or poor action-outcome if overtrained at the action, gives poorer learning

Training implications, hyper-motivation, good sometimes, not always. Reduced action outcome, accelerated habit formation, reduced flexibility once behaviours are learned. Behavioural depression, reduced motivation for task goals, reduced responding to aids, reduced forward going.

What causes changes? Cronic stress, weaning, behavioural needs not being met. Do highly palatsble foods that the animal is not evloved to eat equal to drug stimulantia in humans? 

 

 

Personality influences cognitive abilities in horses, Lansade et al

 

Personality or temperament, all behaviour traits specific. Personality profile after behavioural test 30 min, emotivity to non familiar human, locomotor activity, reactivity to isolation, fearfulness to novel surface and sudden activity

Relationship personality and learning performance and stress

Instrumental tasks and memory tests, speed of learning, then stress

Fearful horses always have lower learning performance when stressed, and when stress is not linked to task. Attention focused on external happenings. Fearful horses often perform better when no stress or if stress is linked to task/negative reinforcement. Enhanced alertness.

The way of learning: habitual or goal-directed, touching objects less when food given for free than when got reward.  The most fearful can focus attentively while maintaining to do a task

 

 

Communication through symbol use, a novel method to study horse preferences for blanketing, Mejdell et al

 

Symbol learning for blanket put on, taken off and no change, the horse decides the outcome. All 23 horses learned within two weeks, some were slower than others. Touch a symbol hung up on the fence with the nose.

Bad weather in February no horses wanted blanket off, warm sunny days in May all wanted blankets off. Warm-bloodied horses often wanted to keep the blanket on, compared to cold-bloodied. though Individual preferences significant.

 

 

Foal's learning performance in four different tasks, Christensen

 

No golden standard for learning in horses. Pressure test with algometer to move hindleg to the side. Visual, one bucket containded food. Clicker test, shape to follow target. Spatial reversal, establish preference for which way to go.

Found no correlations, probably need to have other learning tasks. Or no result is the result that there are no differences in learning.

 

 

Social transmission of habituation from mares to their foals, Janne Winther Christensen

 

Demonstration on the mares for the foals, mares being trained to umbrella, walk over plastic, walking between colourful objects, plastic bag etc before foals being born. 

Foals trained to wear HR measure belt. Foals walked over plastic with mare outside rope, foals in control group (no precious demo by mare for the foals) avoided plastic, same with colourful objects, plastic bag and umbrella. 

Then not touched for a month, new test with also new objects, same result.

Habituation between mare and foal, generalised for new objects, habituation does not disappear.