Ruminants Anatomy

In Hinduism, the cow is a symbol of wealth, strength, abundance, selfless giving and fully earthy life

Objectives – Chapter 10• Know and understand the zoological classification of the species.• Know and be able to proficiently use terminology associated with

the species.• Know normal physiological data for the species, and be able to

identify those that are abnormal. • Identify and know the uses of common instruments relevant to

the species. • Describe prominent anatomical or physiological properties of the

species.• Identify and describe characteristics of common breeds. • Describe normal living environments and husbandry needs of

the species.• Understand and describe specific reproductive practices of the

species.• Understand specific nutritional requirements of the species.

Zoological Classification

• Kingdom• Phylum• Class• Order• Family• Genus• Species

• Animal• Chordata• Mammalia• Artiodactyla• Bovidae• Bos• Tarus or Indicus

Terminology• Cow: Mature female• Bull: Mature male• Steer: Castrated male• Heifer: Immature female• Calf: Neonate• Heifer calf: Neonate female less than one year

of age. Can be called first, second, third or fourth calf heifers.

• Bull calf: Neonate male younger than 1 year of age

• Calving: The act of parturition

• Musculoskeletal

Anatomical Terms

Bovine Skeleton 7, 13, 6, 5 (fused), 18-20: Olecranon; Ligamentum nuchae

Types - boneshumerus, radius, femur, tibia,metacarpals, and metatarsals

carpal andtarsal bones

sternum, ribs, scapula,and certain skull bones

vertebraeand certain facial bones

patella,and proximal and distal sesamoid bones of thedigits.

Cow and Sheep Skull • The brain is situated within

the cranium - a box-like posterior part of the skull.

• The brain is connected to the spinal cord through a large hole, the foramen magnum.

• The foramen magnum is flanked by two large knobs or occipital condyles that form a joint with the first cervical vertebra of the neck.

• Sinuses or spaces are present between the inner and outer cranial walls.

Meningoencephalocoele

Nasal sinus: MCF

Digital section of head with removal of nasal septum, showing accumulated fibrinous secretions lodged in the anterior portions of the left nasal turbinates (arrow).

• Coronoid process is located medially to the zygomatic archProcess allows muscle leverage to be exerted onto the

mandibleMandibular condyle: joint between the skull and the lowerIn cattle and sheep, the mandibular condyle is relatively flat and allows considerable movement in a horizontal plane.

Lateral movement is important in animals whose teeth work with a grinding action.

• Ruminants such as cattle, sheep and goats are herbivores with a unique digestive system.

• A prominent feature of ruminant dental anatomy is that they lack upper incisors, having instead a "dental pad", as shown in the image to the right of a goat.

DENTAL FORMULASpecies Dental Formula Total # teethCanine - puppy 313

31328 (NO MOLARS)

Canine - adult 31423143

42 (EXTRA MOLAR ON MANDIBLE)

Feline - kitten 313312

26

Feline - adult 31313121

30 (EXTRA PRE-MOLAR ON MAXILLA)

Equine - adult 3133314/33

40 0r 42

Porcine - adult 31433143

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Bovine adult 00333133

32 (NO UPPER INCSORS – DENTAL PAD)

Dental Formulae

0 0 3 3 1 3

0 0 3 3 3 1 3 3

The dental anatomy of all ruminants is similar • In the dental formulae shown above, cattle are depicted

as having 3 incisors and 1 canine tooth. Some authors prefer to state that they have 4 incisors, with the canine tooth refered to as the fourth or corner incisor.

• Llamas*

=10Deciduous

=16Permanent

Llama and Alpacas

Maxilla and mandible, llama. Maxillary teeth shown are the third incisor and canine. Mandibular teeth shown are I1-I4. The llama fighting teeth are the upper third incisors, upper canines, and lower fourth incisors (six total teeth). The fighting teeth Courtesy of Dr. Bradford B. Smith and Dr. Karen I. Timm

Tooth Eruption Deciduous Permanent

Incisors Birth - 2 weeks

18 - 48 months

Premolars Birth - 1 weeks

24 - 36 months

Molars 6 - 30 months

• CD

Maxillary Arcade • Note the lack of

incisors

Maxillary Arcade(Lateral view)

Mandibular Arcade

Mandibular Arcade(Lateral view)

The wide gap that separates the incisors (or dental pad on the maxilla) from the premolars is called the diastema.

• The vertebral column or backbone is the main axis of the skeleton and it protects the spinal cord.

• The spinal cord is located in a neural canal formed by a long series of neural arches, each contributed by a different vertebra.

• The neural arch of each vertebra is supported on the body or centrum of the vertebra. In some types of vertebrae, the neural arch extends dorsally as a prominent spine that may be called a dorsal spine, a neural spine or a spinous process.

Abscess of vertebral body

types of vertebrae

• NAME--------REGION---------BEEF--------------LAMB • Cervical--------Neck------------------7-----------------------7 • Thoracic-------Ribcage---------------13---------------------13 to 14 • Lumbar--------Loin--------------------6----------------------6 to 7 • Sacral ---------Sirloin------------------5----------------------4 • Caudal---------Tail--------------------18 to 20--------------16 to 18

• The first cervical vertebra, the atlas, articulates with the skull and is greatly modified in shape to form a joint that enables the animal to nod its head up and down.

• Rotation or twisting of the head occurs from the joint between the atlas and the next cervical vertebra, the axis.

• The ligamentum nuchae is a very strong elastic ligament in the dorsal midline of the neck, and it relieves the animal of the weight of its head. Were it not for the ligamentum nuchae, the head of the standing animal would droop between its forelimbs

Plan of neck in beef, showing:1, ligamentum nuch; 2, atlas; and 3, axis. The ligamentum nuchae is pale yellow

assist the extensor muscles of the head and neck, extending from the occipital bone to the spinous processes of the thoracic vertebrae

Contagious Bovine Pleuropneumoniae

Exposed Atlanto-Occipital joint with severe thickening of the meninges and fibrin deposits

Ribcage

• The cage formed by thoracic vertebrae, ribs and sternum is an essential component of the respiratory system.

• Thoracic vertebrae are distinguished by their tall dorsal spines, many of which point towards the hindquarter and are known as the feather bones.

Comparative VertebraeCervical Thoracic Lumbar Sacral Coccyge

al

Canine/ Feline

7 13 7 3 6-23

Equine 7 18 7 5 15 - 21

Bovine 7 13 6 5 18 - 20

Porcine 7 14 - 15 6 - 7 4 20 - 23

Ovine 7 13 6 – 7 4 16 - 18

The structure of the ribcage is rather variable in lamb carcasses

BEEF----------LAMB Total pairs of ribs-------------13--------------13 to 14 Pairs of sternal ribs-----------8----------------8 Pairs of asternal ribs----------5---------------5 to 6 Number of sternebrae--------7---------------6 to 7

• MEATS

Pelvis• The pelvis and the

sacrum form a ring of bone completed ventrally by the pubes.

• The left pubis is separated from the right pubis by fibrocartilage which, at parturition, may soften to allow movement between the bones of the pelvis.

• The pubes are separated when carcasses are split into left and right sides in the abattoir.

Plan of the pelvis in a hanging beef carcass showing:1, lesser sciatic notch; 2, ischiatic spine; 3, greater sciatic notch; 4, psoas tubercle; 5, obturator foramen; 6, symphysis pubis;7, ischium; and 8, ilium.

V

Pubic

Another plan of the both sides of the pelvis in a hanging carcass showing: 1, tuber coxae; 2, acetabulum; 3, acetabular ramus of ischium; 4, tuber ischii; 5, symphysis pubis; 6, ilium; 7, pubis; and 8, ischium

The tuber coxae forms the basis of the point of the hip (hooks)

OS COXAE - PELVIS

The pelvic girdle comprised of the illium, ishium, and pubis. This is the largest of the the flat bones

Ilium – Ischium - Pubis

• The largest and most anterior of the three parts of the pelvic girdle

• Hip bone/ Pin bone

• Smallest of the three parts of the pelvic girdle

Aitch bone – Body of shaft of Ischium

• The aitch bone is curved in steer and bull carcasses, is moderately curved in heifers, but is straight in cow carcasses

Forelimb skeleton -Scapula• The scapula is not fused to

the vertebral column (like the pelvis in the hindlimb), and this allows muscles that hold the scapula to the ribcage to function as shock absorbers during locomotion.

• The scapula has a distal socket joint for the next bone in the forelimb, the humerus.

• This socket of the glenohumeral joint is called the glenoid cavity . – The glenoid cavity is wide and

shallow, unlike the ball and socket joint in the hindlimb which is narrow and deep.

ACROMION• On the lateral face

of the scapula is a prominent ridge of bone called the spine of the scapula. – In beef (OX)

carcasses, the scapular spine is extended distally as a prominent acromion process.

Humerus – “Arm bone / clod bone”

• Proceeding distally down the forelimb, the bone that articulates with the scapula is the humerus.

• Proximally, the humerus has a relatively flat knob or head to fit into the glenoid cavity of the scapula. Two well defined condyles on the distal end of the humerus contribute to the hinge joint at the elbow.

Radius & Ulna: (‘Foreshank bone’)

• The radius is joined to the ulna and is the shorter and more anterior bone of the pair

Beef shankbones showing: 1, distal end of humerus; 2, olecranon fossa; 3, olecranon process;, 4,radius; 5, ulna; and 6, carpal bones.

Femur – ‘Round bone or leg bone’

• The proximal bone of the hindlimb is the femur or round bone. The articular head of the femur is deeply rounded and it bears a round ligament that holds it into the acetabulum.

• Another distinctive feature of the femur is the broad groove between the two trochlear ridges located distally. The patella or knee cap slides in this groove

Tibia – ‘hind shank – hock bone’• In beef and lamb

carcasses there is a single major bone, the tibia or shank bone, located distally to the femur.

• Tibia and fibula 1, medial condyle, 2, lateral condyle; 3, tibia, and 4, fibula.

Congenital

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foot (Dyce)foot (Dyce) dewclaw (hoof dewclaw (hoof only)only)

claws (hoof)claws (hoof)

digits ordigits ortoestoes

fetlock jt.fetlock jt.

pastern jt.pastern jt.

coffin jt.coffin jt.

bulb (heel)bulb (heel) solesole wallwall

Foot, Digits, Claws and Dewclaws

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Common and Lateral Digital Extensor TendonsNote: “just like” the Note: “just like” the horse, but double horse, but double because 2 digits. because 2 digits.

LL MM

lateral digital extensorlateral digital extensor lateral headlateral head

medial head medial head

Dorsal view:Dorsal view:

common digital common digital extensor:extensor:

IIIIIIIVIV

Note: Note: threethree palpable extensor palpable extensor tendons, rather tendons, rather than two as in the than two as in the horse.horse.

Cloven (split) hoof: Cattle/ goat/ sheep2 digits: III and IV with 3 phalanges. Digits II and V: vestiges

Weight bearing: front medial and hind lateral

Erosion on the foot caused by FMD or Vesicular Stomatitis which are grossly indistinguishable from one another.

References• http://w3.vet.cornell.edu/virtualvet/bovine/

tissue_lesions.aspx?Tis=37• http://bovine.unl.edu/bovine3D/eng/nIntro.jsp• http://studentvet.wordpress.com/2010/07/29/bovine-

forelimb/#Humerus• McBride Douglas, Learning Veterinary terminology, 2002• http://vetmed.illinois.edu/courses/imaging_anatomy/

bovine/hindlimb/foot/ex01/ex01.html• K Holtgrew-Bohling , Large Animal Clinical

Procedures for Veterinary Technicians, 2nd Edition, Mosby, 2012

• www.vet.k-state.edu/depts/ap/faculty/klimek/.../B-P248-268.ppt