Growth and Development

Body composition

Feed efficiency is closely related to what

Growth

Increasing body weight until mature body weight until mature size is reached

False

The term growth includes excess fat deposition (T/F)

Increase in cell size and number

Increase in bone, muscle, fat, and connective tissue

What causes growth

Genetics (DNA)

What is a huge factor in amount of growth/ adult size?

Hyperplasia

Increase in cell number; occurs before birth (few exceptions)

Adipose cells

Continue to divide after birth, fat cells

Skin

Some adipose

Intestinal lining

Blood cells

What cells continue to divide after birth

Hypertrophy

Increase in cell size

Muscle

Nerve

Most adipose

Which cells increase in cell size, born with number that you have do not divide

Endoderm

Gives rise to GI tract, lungs, and bladder

Mesoderm

Gives rise to skeleton, skeletal muscle, and C.T.

Ectoderm

Gives rise to skin, hair, brain, and spinal cord

Prenatal growth

Growth before birth, fetal growth

Nucleus of the cell

What is the center of prenatal growth

Physiological importance

Order of tissue growth is determined by (blank)

Last trimester

When does the largest increase in weight of fetus occur

Early pregnancy

When is the head larger then the body of the fetus

5-7%

Birth weight is what percentage of mature weight

60%

Leg length at birth is what percent of mature length

50%

Height at withers at birth is what percentage of mature height

1/3

Hip and chest width at birth are what fraction of mature size

Tissues

Specialized groups of cells that function together

Organs

Groups of tissues that perform specific functions

System

A group of organs that function to accomplish a larger function

Skeletal

Bone, teeth, and cartilage

Protects organs and gives basic form and shape to body

Muscular

Skeletal, cardiac, and smooth

Skeletal muscle

Largest component of red meat products

voluntary

Smooth muscle

Located in digestive, repro, and urinary

involuntary

Cardiac muscle

Heart

Good conformation

What is essential to good growth and efficiency

Circulatory

System that transports blood, waste, hormones, and nutrients

Arteries

Transport blood away from heart

Veins

Vessels that carry blood to the heart

Lymph

Transport lymph (intercellular fluid)

Endocrine system

Ductless glands that secrete hormones into blood

Break joint

Lamb

Bone has not fully grown together, less than a year

Spool joint

Mutton

Bones have fused, older than a year

True

All meat producing animals follow a common pattern of bone development (T/F)

Epiphyses

Diaphysis

Long bones consist of…

Epiphyses

Knobs at the end of long bones

Diaphysis

Long shaft region of long bones

Medullary cavity

Cavity within bones that is filled with bone marrow

Compact bone

Very dense, found in periphery of bones

Spongy bone

Lighter less dense bone

Epiphyseal plate

Located at each end of long bones between epiphyses and diaphysis, consist of cartilage and facilitates bone growth in length

ossifies to limit growth

They have gotten leaner and more efficient

What changes have occured in animal production in the last 50+ years

False

The number of muscle fibers significantly increase after birth (T/F)

Osteoblasts

Bone matrix production, bone cell precursor

Osteocytes

Maintenance of bone matrix, mature osteoblasts

Osteogenesis

Formation of bone

Periosteum

Outer epithelial layer of bone, diameter growth occurs through deposition of new osteocytes

Cartilage growth is faster than osteoblasts

How does the shaft of the long bone lengthen

Cartilage growth stops or is overcome by ossification

What stops growth of the long bone

Growth plate closure

Fusion of epiphyses and diaphysis into single bone

Osteoclasts

Involved in bone resorption

Breakdown and remodeling bone

Triggered by hormones

Bone resorption exceeds bone formation

What causes brittle bones in older age

Remove bone inside to form more space for bone marrow

Why do osteoclasts break down bone

Amount of cartilage

What do we use to estimate age of meat beef carcasses

Posterior to anterior

What direction does the vertebral column mature

Maturity

What is the primary factor in determining carcass quality grade and best single indicator of meat tenderness

Yield grade

How much edible meat is on a carcass

Quality grade

Includes traits such as tenderness, juiceness, and flavor

Increased connective tissues

What happens as muscle gets older and causes it to lose tenderness

Low proportion of bone

High proportion of muscle

Optimum amount of fat

Traits of a superior carcasses

Fat

Lean (muscle)

Bone

Primary products from meat animals

When to slaughter

What does understanding growth and development help you to know

Frame size

Sex

Muscling

What effects carcass composition

Height at hips

Age

What is frame size determined by

estimate mature size

Knowing frame size allows you to…

Mid to late stages of fetal development

When does adipose development begin

False

Fat deposition creates new fat cells not enlargement of cells (T/F)

KPH fat

Kidney pelvic and heart fat

roughly 3.5%

Subcutaneous fat

Fat under the skin

Deposited in layers and separated by connective tissue

Intermuscular fat

Between the muscle

Often surrounds moving muscle parts, fills space between bone and points of muscle attachment

Intramuscular fat

Inside the muscle, marbling

Occurs in later stages of growth and first to leave in starvation

Dairy breeds

Which cattle breeds have higher KPH fat

Swine

Which animal has the largest quantity of subcutaneous fat

Cattle

Which animal have the largest quantity of intermuscular fat

12th rib

Back fat is measured where in cattle

Hormones

Blood

Waste

Nutrients

What is transported by the blood

Young animals

At what stage do animals grow more quickly and lay on more muscle than fat

Sex

What makes a big difference in the rate of fat deposition

non- castrated males

Which sex is the leanest overall

Steers

Are steers or heifers leaner

Gilts

Are gilts of barrows leaner

Testosterone

What hormone allows bulls and rams to have more efficient weight gain and leaner carcasses

intramuscular

Testosterone inhibits (blank) fat

Estrogen

What hormone increase the rate of closure of the epiphyseal plate and slows growth

Contraction

What is the major function of muscles

Unique proteins arranged in filaments that interact by sliding past each other to provide contractile force

How do muscles contract

Striated tissue

Organized filaments, skeletal and cardiac

Non-striated tissue

Filaments lack organization, smooth muscle

Bundles

Groups of muscles that make up muscles

Muscle cell

What muscle bundles are made of

Myocyte

muscle fiber

myofiber

Synonyms for muscle cell

Myofibrils

Basic functional unit of the muscle fiber contractile system

Microfilaments

What makes up myofibrils

Actin

Thin type of microfilament

Myosin

Thick kind of microfilament