Lecture 1.4 – case 6 horses
Self -study
Equidae, family of the equines
The horse that is nowadays used for domestic purposes such as riding and pulling
a carriage, belongs to the Equidae – the family of the equines. They belong to the
Perissodactyla, also known as the odd-toed ungulates. Members of this order
carry their weight on the terminal bones of the toes. The toenails form hoofs.
Asses/donkeys:
– Equus acinus, Large head, long ears, multiple breeds ranging in size (180 –
400 kg)
– Equus kiang, 250 – 440 kg
– Equus hemionus, 200-260 kg.
Zebras:
– Equus grevyi (approximately 400 kg, largest zebra species)
– Equus burchelli (290-340 kg)
– Equus zebra (mountain zebra)
– Equus quagga
Horses:
– Equus caballus przewalski (Mongolia, 200-300 kg)
– Equus caballus (50-2000 kg)
The first member of the Equidae and the ancestor of all equines was
hyracotherium, also known as eohippus (dawn horse).
Major changes since 55 million years ago:
1. Grown 30 cm in height, lengthening of the legs because of predators.
2. From 4-toud to single-toed organisms, one hoof.
3. Spread geographically, from North- America to the world.
4. From dwellers to grazers of the plains
Summary of wild horses lifestyle:
- Grazers, relatively poor vegetation
- Adapted teeth with continuously growing roots, The mandibular joint (jaw
joint) and jaw muscles allow for a relatively wide and powerful lateral
rotation of the lower jaw.
- Single stomach with specialized cecum and colon (hindgut)
- Herd animals
- Excellent sight, smell and hearing
- Gestation of 11 months
- Nursing period of 7 months
The first signs of horses submitting to humans date from approximately 4000 BC.
Around that time, humans tried to domesticate the horse, which is a process of
genetic adaptation of the horse to meet the needs of humans. In this era, the
horse functioned mainly as a food source. The first clear evidence of the horse as
a mean of transport has been found in the southern Mesopotamia, where an
, obvious horse and carriage combination was discovered. The riding of horses
became customary later, around 1000 BC.
Selection is an obvious step after domestication: humans choose the horses that
are best fit for their purpose. The next step was selection for a purpose, in which
at first the distinction was made between light horses for speed and heavy horse
for strength. Crossbreeding led to over 150 breeds nowadays.
Every breed is under surveillance of a studbook. The studbook determines the
rules of breeding for that specific breed: it determines the breeding goal and
develops a breeding program.
- Open: allows addition of ‘foreign’ blood to improve the breed, like KWPN.
- Closes: which values purebreds and doesn’t allow horses from other breeds.
Anatomy:
Bones:
Vertebral column The spine is part of the skeleton; it supports the system of
bones and joints. Apart from providing support, the skeleton protects the
vulnerable organs, provides surfaces of attachment for the muscles, and plays an
important role in locomotion due to its many levers.
- Cranial, head
- Axial, spine and ribs the appendicular part is formed by the bones and the
joints of the shoulder- and pelvic girdle and by the limbs.
we can find some elongated bones with a hollow cylindrical shape. Hollow bones
are better at withstanding bending forces than compact bones of an equal length
and mass. Apart from providing strength, these bones are also important in
locomotion: they function as a lever for the muscles that move the limbs.
Joints:
Bones are connected via joints. Some bones are tightly connected through fibrous
and cartilage joints while other joints allow for free movements in the limbs,
called synovial joints. The bones of the skull are with fibrous joints, called sutures.
The second type of fixed joints – cartilage joints – are often temporarily present
and are being converted into bone after the growth is completed. The vertebrae
are also connected with ligaments, which allow movement only in the right
direction.
Muscles:
All body movements are being controlled by muscles that have an inducing or
reducing influence on the movement.
- Cardiac muscle, striated heart
- Smooth muscle, viscera internal organs and blood vessels
- Skeletal muscle, striated attached to the skeleton
Musculoskeletal system: The entire system of bones, joints, muscles, tendons,
ligaments and connective tissue.
Self -study
Equidae, family of the equines
The horse that is nowadays used for domestic purposes such as riding and pulling
a carriage, belongs to the Equidae – the family of the equines. They belong to the
Perissodactyla, also known as the odd-toed ungulates. Members of this order
carry their weight on the terminal bones of the toes. The toenails form hoofs.
Asses/donkeys:
– Equus acinus, Large head, long ears, multiple breeds ranging in size (180 –
400 kg)
– Equus kiang, 250 – 440 kg
– Equus hemionus, 200-260 kg.
Zebras:
– Equus grevyi (approximately 400 kg, largest zebra species)
– Equus burchelli (290-340 kg)
– Equus zebra (mountain zebra)
– Equus quagga
Horses:
– Equus caballus przewalski (Mongolia, 200-300 kg)
– Equus caballus (50-2000 kg)
The first member of the Equidae and the ancestor of all equines was
hyracotherium, also known as eohippus (dawn horse).
Major changes since 55 million years ago:
1. Grown 30 cm in height, lengthening of the legs because of predators.
2. From 4-toud to single-toed organisms, one hoof.
3. Spread geographically, from North- America to the world.
4. From dwellers to grazers of the plains
Summary of wild horses lifestyle:
- Grazers, relatively poor vegetation
- Adapted teeth with continuously growing roots, The mandibular joint (jaw
joint) and jaw muscles allow for a relatively wide and powerful lateral
rotation of the lower jaw.
- Single stomach with specialized cecum and colon (hindgut)
- Herd animals
- Excellent sight, smell and hearing
- Gestation of 11 months
- Nursing period of 7 months
The first signs of horses submitting to humans date from approximately 4000 BC.
Around that time, humans tried to domesticate the horse, which is a process of
genetic adaptation of the horse to meet the needs of humans. In this era, the
horse functioned mainly as a food source. The first clear evidence of the horse as
a mean of transport has been found in the southern Mesopotamia, where an
, obvious horse and carriage combination was discovered. The riding of horses
became customary later, around 1000 BC.
Selection is an obvious step after domestication: humans choose the horses that
are best fit for their purpose. The next step was selection for a purpose, in which
at first the distinction was made between light horses for speed and heavy horse
for strength. Crossbreeding led to over 150 breeds nowadays.
Every breed is under surveillance of a studbook. The studbook determines the
rules of breeding for that specific breed: it determines the breeding goal and
develops a breeding program.
- Open: allows addition of ‘foreign’ blood to improve the breed, like KWPN.
- Closes: which values purebreds and doesn’t allow horses from other breeds.
Anatomy:
Bones:
Vertebral column The spine is part of the skeleton; it supports the system of
bones and joints. Apart from providing support, the skeleton protects the
vulnerable organs, provides surfaces of attachment for the muscles, and plays an
important role in locomotion due to its many levers.
- Cranial, head
- Axial, spine and ribs the appendicular part is formed by the bones and the
joints of the shoulder- and pelvic girdle and by the limbs.
we can find some elongated bones with a hollow cylindrical shape. Hollow bones
are better at withstanding bending forces than compact bones of an equal length
and mass. Apart from providing strength, these bones are also important in
locomotion: they function as a lever for the muscles that move the limbs.
Joints:
Bones are connected via joints. Some bones are tightly connected through fibrous
and cartilage joints while other joints allow for free movements in the limbs,
called synovial joints. The bones of the skull are with fibrous joints, called sutures.
The second type of fixed joints – cartilage joints – are often temporarily present
and are being converted into bone after the growth is completed. The vertebrae
are also connected with ligaments, which allow movement only in the right
direction.
Muscles:
All body movements are being controlled by muscles that have an inducing or
reducing influence on the movement.
- Cardiac muscle, striated heart
- Smooth muscle, viscera internal organs and blood vessels
- Skeletal muscle, striated attached to the skeleton
Musculoskeletal system: The entire system of bones, joints, muscles, tendons,
ligaments and connective tissue.
