ASCI 224 midterm 1 study guide PDF

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Summary

Professor Sarah Stewart. covers history, breeds, behavior, confirmation, unsoundness...

Description

Key: Important *KNOW FOR EXAM* Definitions Tips and Tricks for memorization

Units Sections Subsections Subsubsections

ASCI 224 Midterm Equine Evolution Objectives: -

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Describe the process of equine evolution and changes that occurred - Branched evolution - Modern horse (Equus) originated in North America - Migrated to the rest of the world via glaciers and land bridges during the pliocene epoch - Went extinct in North America during the Ice Age due to: - Environmental pressures - Long gestation periods - Hunted - Reintroduced to North America by Spanish explorers in the late 1400s/early 1500s List the four evolutionary trends exhibited by horse fossils - Increase in size - Increase in size of cheek teeth - Lengthening of face - Reduction in number of toes - Eohippus, mesohippus, merychippus, pliohippus, equus Reflect on how the value of the horse has changed throughout history - First horses were hunted - Evidence in location of bones and knife marks on bones - Then used as work animals - First domesticated in china - Used for travel, warfare, farming, building - Now used for recreation - Leisure riding, competition, ranch labor Discuss classifications of equine behavior - Environment and genetics - Manipulate the environment to train horses - Training for desired behavior can be started during the imprinting phase

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- First 48 hrs of a horse’s life Describe how horses respond to stimuli and the psychology behind training - To modify the horse’s behavior, the trainer has to manipulate the horse’s m - Stimuli is unconditioned or conditioned, of the conditioned stimuli there are basic cues and new cues - Horses have minor and major responses to stimuli - Horses respond to stimuli by moving away from pressure or escape. The desired response to the stimuli is reinforced through positive and negative reinforcement

History -

Ancestors of the modern horse originated 50-60 million years ago in North America “Equus” (the modern horse) originated in North America 1 million years ago Migrated to other parts of the world during Pliocene Epoch via glaciers and land bridges Started to disappear from North America during the Pleistocene Epoch (ice age) - WHY? Gestation period too long for many foals to be born to maintain population numbers, environmental pressures, hunted by early humans

Hunted by humans -

Earliest association between man and horse was one-sided - Man hunted and subsited on horse meat Evidence: - Cave paintings - 40,000 horse bones that existed 25,000 years ago were found at the bottom of a rock shelter - Men ran horses to their death over cliff

Domestication -

Approx 5,000 years ago in china Horses served as a means for food, travel, warfare, draft animals for farming and building Spanish missions into the Rio Grande valley in mid 1500s brought large numbers of livestock (horses reintroduced)

Equine Evolution -

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Modern horse wasn’t the “goal” of evolution, simply the only genus to survive The horse is a classic example of evolution due to: - Significant changes in size and bone structure - In response to environmental changes - Well preserved fossil remains Branching - Not all horses share the same evolutionary trends - Modern horse is the only surviving branch - Equus ferus caballus Differences in evolution - Doesn’t occur at the same time and rate - Some time periods the horse changed a great deal or hardly at all - Different evolutionary changes can occur at the same time

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Some changes are reversed over time

Major changes in 4 areas: -

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Increase in body size Reduction in the number of toes Increase in the size of cheek teeth - Due to change in diet: - Ancestors had brachydont teeth - low crown - Modern horse has hypsodont teeth - high crown (for grazing) Lengthening of the face

Stages of Evolution Eohippus -

Eocene Epoch - 50-60 million years ago “Dawn Horse” - part of the hyracotherium group of species Evolution characteristics: - Size: 2 feet long, 8-9 inch at shoulder (size of fox) - # of toes: 4 toes on front feet and 3 on hind, pads behind - Cheek teeth: Brachydont tooth structure suggests that it was a browser - Ate soft leaves and plant shoots - Face: Long face with 44 teeth - Alert ears, doglike furry coat, swishy tail

Mesohippus -

Oligocene Epoch - 35 million years ago “Middle Horse” Reason for evolution: - Climate change, forest thinning and grass prevalence Evolution characteristics: - Size: larger than Eohippus, 24 inches at shoulder - # of toes: 3 toes on front and hind - Strengthening of middle toe - Lateral supporting toes shrunk - Toes end in little hooves, still had a pad behind - Cheek teeth: low crowned brachydont teeth for browsing

Merychippus -

Miocene Epoch - 20 million years ago “Ruminant Horse” Increasingly gregarious and lived in herds - First representation of modern horse Evolution characteristics: - Size: approx 35 inches at shoulder - # of toes: 3 toes - Weight carried on enlarged single hoof on central - Middle toe which thickened and hardened

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- Lateral toes diminished and no longer touched the ground - Feet without pads Cheek teeth: grinding teeth similar to modern horse for grazing

Pliohippus -

Pliocene Epoch - 5-7 million years ago “More horse” Gregarious - spread from North America to South America and then to Asia, Europe, Africa Evolution characteristics: - Size: about height of donkey - # of toes: first true monodactyl - Used speed to flee from predators - Cheek teeth: longer cheek teeth, high crown teeth for grazing - Lived on plains and ate grass - Nearest approach to modern day horse

Equus Caballus -

Modern Day - 1-2 million years ago “The modern horse” Became extinct in Western Hemisphere ~ 8 thousand years ago, reintroduced to North America by Spanish explorers in the late 1400s

Eohippus

Mesohippus

Merychippus

Pliohippus

Equus Caballus

Epoch evolved Eocene Epoch, 50-60 mya

Oligocene Epoch, 35 mya

Miocene Epoch, 20 mya

Pliocene Epoch, 5-7 mya

1-2 mya in NA

Nickname

“Dawn horse”

“Middle horse”

“Ruminant horse” “More horse”

Modern day horse

Size

2ft long, 8-9in tall

Larger than Eohippus

35 inches tall

Height of donkey

Largest evolved species

Number of toes

4 front toes 3 hind toes Pads behind

3 toes w/ pads and little hooves Smaller lateral toes

3 toes, 2 lateral toes don’t touch the ground No pads

1 toe, first monodactyl

1 toe

Cheek teeth

Brachyodont teeth for browsing

Brachydont teeth

Hypsodont teeth for grazing

Hypsodont teeth for grazing

Hypsodont teeth High crown for grazing

Other

Solitary, no herds

Climate change, forest thinning, grass abundance drove evolution

More gregarious and lived in herds

Nearest approach to modern day horse

Became extinct in Western Hemisphere 8k yrs ago

Behavior Principles of Training & Management Equine behavior -

To work with and/or train a horse safely and effectively, one must understand their behavior and reactions to environment Understanding how and way a horse responds to external stimuli allows a handler/trainer to anticipate and understand certain responses - Creates a more positive learning environment for horse and handler

Training -

Horse training = behavior modification Horses’ ability to learn, solve problems, or survive the effects of severe stress is greatly influenced by the environment in which that animal has been raised Trainer must manipulate said environment in order to create desired responses within the animal

Desensitization

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- Stimuli - Response - Reinforcement Repeat same action until achieved desired response - (stands still) when achieved desired response, reinforce with removing stimuli

Early experiences -

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Imprinting - uses desensitization but is specific only to the newborn foal - Dr. Miller - Critical learning period for the horse - first 48 hours of life - Used in the industry but no research to prove its effectiveness Results of imprinting: - Social bonding - Sensitization of stimuli - Desensitization of stimuli - Submissive behavior to humans

Psychology of Training -

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To modify behavior, the trainer must manipulate the horse’s environment  Environment is divided into: - Stimuli - an event or cue that evokes a specific reaction - Response - the acts or movements of the horse - Reinforcement - strengthening responses to certain stimuli Behavior = environment + genetics - Environment - trainer can change with stimuli, response, reinforcement - Genetics - trainer can not change, but influences horse’s abilities

Stimuli -

Unconditioned - natural response results with no prior practice - Very few examples in training - Ex: a horse will move away from pressure

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Conditioned - stimuli that has to be learned through practice - “cues” - Ex: learning to cross the front legs (spins/rollbacks/ turn on the haunches, pirouettes) - Types of Conditioned Stimuli: - Basic Cues:  training starts with a few basic cues that are closest to being natural - Ex: direct rein pressure response - horse is shown the direction it should go - New Cues (building off basic cues): presented by pairing a new cue with a basic cue in a daily training routine - New cue presented first, then followed by the old cue - Ex: teaching a horse to neck rein, saying “whoa to stop horse

Responses -

Refers to the acts or movements that the horse makes in response to stimuli Training involves teaching the horse to make the desired response Major responses - the result of many minor responses - Ex: stopping and jumping

Reinforcement -

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Certain events are capable of strengthening responses to certain stimuli - Primary - natural, expected - Ex: feed, rest - Secondary - learned over a given period of time - Ex: general acts of kindness (majority of training) Learning can not be accomplished without reinforcement (positive and negative) - Positive Reinforcement - the addition of a stimulus upon correct response - “Reward training” - Ex: pat on neck, spoken words, treats - Usually untrained horses don’t appreciate them until they are associated with primary reinforcers - Negative Reinforcement - aversive stimuli that the horse will work to avoid or get rid of if given a choice - The removal of a stimuli upon correct response - Majority of training - Methods of training include - punishment, escape, avoidance

Breeds, Types & Classes of the Horse Objectives -

Apply scientific and accurate nomenclature for the horse that is associated with age, sex, or use Differentiate between breeds, colors, markings, types, classifications Identify common breeds and their general use in each class Discuss trends and issues within the equine industry

Breeds Breeds - Groups of animals that have certain distinguishable characteristics - Function, confirmation, color - Through selection, line-breeding, and outcrossing - Speed, strength, size, good nature, hardiness, athletic ability, etc

Background -

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Many recognized breeds have certain foundation sires - All registered foals must trace their ancestry back to these stallions - Ex: thoroughbreds Color breeds with associated requirements - pinto, buckskin Conformational breed requirements - certain height

Registration documents and pedigrees -

AQHA The Jockey Club - TB live cover requirement - Advantages - value of stallions - Diversity of genetic pool - Tradition - Disadvantages - both parties can get hurt - Increase risk of STI’s - More labor intensive - Mare owners are restricted to certain stallions

Color Breeds -

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Associations created to preserve color characteristics - White (pink skin) - Palomino (dilution of chestnut) - Cremello (double dilution of chestnut) - Buckskin / dun (dilution of bay) - Perlino (double dilution of bay) - Dun has dorsal stripe Spotted Breed Associations - Appaloosa - Paint - bloodline requirement - APHA (quarter horse, thoroughbred, paint) - Tobiano - white crossing over the back - white legs, multi colored tails - larger white patches - Overo - solid color over the back - Solid tail

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- Smaller splotches of white Pinto - types - Need only to match the designated types - Hunter, pleasure, saddle, stock type

The Light Horse -

“Hot blooded” - lighter bone structure, hotter temperament 12-17.2 hh; 900-1400 lbs Primary uses - riding, driving, showing, racing, utility on a ranch Capable of more action and speed than draft-type Includes most color breeds

Arabian -

Developed in mideast / northern Africa 2-3,000 years ago Endurance breed - general purpose and great reputation for Characteristics: - Height - 14.1-15.1 hh - Weight - 800-1,000 lbs - Distinctive head and neck, skeletal differences - One less lumbar (tail) vertebrae, one less rib

Thoroughbred -

Developed largely from Arabians - 3 foundation sires, 2 of which are Arabs Most influential in development of light horse breeds Developed for speed at intermediate distances Characteristics: - Height - 15.1-16.2 hh - Weight - 900-1,150 lbs

American Mustang -

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North American Mustang Association dedicated to preserving and continuing the best specimens of the mustang - Has stud books, holds shows - Any color acceptable 1971 Wild Free Roaming Horses and Burros Act - Protects wild horses and burros on public land after threat of wiping out population of wild horses Mustang management practices - $1000 to adopt a wild mustang - Contraceptive - PZP (porcine zona pellucida) - Lasts 1 year - Drawbacks - labor → documentation - Expense - Public perception

Tennessee Walking Horse -

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Developed as a general purpose breed - riding, driving, farm work Characteristics: - Solid colors, white markings common - Naturally over-strides at the “running walk” (4 beats) Most affected by the Horse  Protection Act of 1970 - Public outcry due to soring - Soring - caustic subcutaneous / chemicals or physical substances applied to the hoof that caused them pain to the hoof / lower leg - These applications forced the horses to lift their legs higher and faster - illegal - Action devices - legal in the US as long as they don’t have chemicals / sharp chains wrapped on the legs that hit their legs each step

The Draft Horse -

“Cold blooded” - heavy, solid horses with calm temperament Developed in Northern Europe Primarily used for heavy work or pulling Characteristics: - Height - 14.2-17.2 hh - Weight - 1,600 - 2,200 lbs depending on sex, age, condition

The Warmblood -

Middleweight horse types and breeds Primarily originating in Europe Open studbook daily Characteristics: - Height - 15-17 hh - Weight - 1,000-1,500

The Pony -

Distinguished by phenotype A horse that is an approx height or displaying specific conformation and temperament May have descended from wild “draft” subspecies of equus ferus Used in a variety of sports including riding and driving Characteristics: - Height - < 14.2 hh - phenotype is determining factor - Weight - 500-900 lbs - coat characteristics - Stockier - skeletal characteristics - Thicker main and tail

Equine Anatomy Objectives -

Identify the bones in the thoracic and pelvic limbs and the hoof Distinguish between a blemish, an unsoundness, and lameness Draw correlations between structural incorrectness and unsoundnesses in the equine (relate form to function) Identify common unsoundnesses in the horse that are apt to cause lameness. Describe treatment and prognosis Describe 3 stable vices affecting usefulness

Skeleton Axial -

“Trunk” Consists of skull, spine, ribs, sternum, pelvis, tail Skull & mandible, cervical, thoracic, lumbar, sacral, caudal vertebrae

Appendicular -

Forelegs and hind legs Used for locomotion, grooming, defense, feeding Forelimbs are connected to the axial skeleton by muscle only! Lameness: - Forelimb - 80% at the knee joint or below - A result of forelimbs being used to bear most of the weight - Hindlimb - 80% at the hock or stifle joint - A result of the hindlimbs being used for power

Hoof -

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P1 - proximal phalanx / long pastern bone P2 - middle phalanx / short pastern bone P3 - distal phalanx / coffin bone - Provides shape of foot and rigidity needed to bear weight Digital cushion - Expands and contracts to absorb shock and pumps blood from foot back to heart Distal sesamoid bone / navicular bone - Serves as a gliding and bearing surface for the Deep Digital Flexor Tendon (DDFT) - DDFT - Responsible for flexion of foot as it progresses through a stride Laminae - Serves as a means of attachment for hoof wall, coffin bone - Main area of blood  circulation within foot - Laminitis - laminae swells, detaches from hoof wall, coffin bone rotates bc DDFT pulls it back

Unsoundness in the Equine ( forelimb, hind limb, hooves, body, stable vices )

Unsoundness vs Blemish -

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Unsoundness - any condition that interferes or is apt to interfere with the function and performance of the horse - Interferes with function of the horse BUT not specific to gait Lameness - alteration to the horse’s normal movement or gait - Scored 0-5 Blemish - is unattractive but does not and is not apt to interfere with the horse’s overall function - Muscle atrophy or scars A lameness is an unsoundness BUT an unsoundness isn't necessarily a lameness

DJD vs DOD -

Degenerative Joint Diseases - DJD - Normally characterized as slowly developing chronic disease of the joint in which the joint surface (cartilage) wears down - Older/mature horses

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Osteoarthritis Results in pain, subsequent lameness Caused by: - Trauma to joint - Wound and infections Developmental Orthopedic Disease - DOD - Growth disturbances of growing horses. Failure of cartilage to mature - Affects young horses - yearling / 2 year olds - Types - osteochondritis dissecans (OCD), epiphysitis, bone cysts, etc - Caused by: - Nutrition, genetics, increased work at young age

Blemishes and Unsoundness of the Forelimb -

Majority of the unsoundness in the horse results in lameness Forelimb receives the majority of injuries that result from concussion and trauma

Splint - Interosseous Desmitis -

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Calcification or bone growth Location: - Typically the inside of the cannon or splint bone area of the front leg Caused by: - Inflammation or tear of interosseous ligament (between splint and cannon bone) - Trauma, poor confirmation (bench kneese) Treatment: - Splint will “set” with rest, inflammation resolves itself naturally to a bony blemish on cannon bone Unsoundness or blemish? - Initially unsoundness causing lameness, but after treatment it becomes a blemish

Tendonitis - Bowed Tendon -

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Thickening of the back surface of the leg immediately above fetlock SDFT commonly involved but also DDFT - Superficial Digital Flexor Tendon - Origin - SDF...