Growth and Development
What is growth?
Increase in body weight until maturity is reached. In animal production it is an increase in animal tissue: muscle, fat, and bone.
True or False: All meat sold is inspected and will have a shield of approval on the package.
True
Which fat deposit is the highest priority in development?
Fat deposits in order from highest to lowest priority:
1. Perinephritic
2. Intermuscular
3. Subcutaneous
4. Intramuscular
What are the functions of the digestive tract?
Prepare nutrients for absorption
Store nutrients
Build useful products
Reject unused and broken down residue
List and rank body processes from first importance (lowest nutrient levels) to last importance (highest nutrient levels).
Maintenance - support of body processes
Growth - increase in weight or size
Reproduction - proliferation of species
Animal Products - used for human consumption
What are the differences between chronological and physiological age?
Chronological age refers to the animal’s age in terms of units of
time.
Physiological age refers to stages (Landmarks) of development as
the animal grows from conception to maturity.
How do you determine age of an animal?
Age is determined looking at the ossification
(red) of lumbar and thoracic vertebra, shape
and color of ribs and color of lean
Rib bones become wider and whiter as the
animal ages
Lean color changes from bright red to a
muddy red color
True
Hyperplasia - increase in the number of cells
Hypertrophy - increase in cell size
What are the three different classifications of animals? Rank them by complexity of digestive system (simplest to most complex).
Carnivores - meat eaters
Herbivores - plant eaters
Omnivores - plant and meat eaters
Ranking: Carnivores (monogastrics), Ominvores (intermediate tract), Herbivores (ruminants or monogastrics and hindgut fermenters)
What are the 5 classes of feeds? Give one example of one class.
1. Concentrate - corn, sorghum, barley, molasses, bakery by- products
2. Roughage/Forage - Hay, silage, grass, straw
3. Protein Supplement - Soybean Meal, Meat and bone meal, Urea, Fish meal
4. Non-nutritive Additives - Antibiotics, Ionophores, Flavor components, Hormone - like compounds
5. Vitamins/Minerals - salt mix, mineral mix, vitamin mix
How does the proportion of body composition composed of blood, hide, and viscera change as an animal grows?
It decreases. Muscle and Fat continue to grow sigmoidally proportional to weight/size whereas the amounts of blood, hide, and viscera grow more linearly proportional to weight/size.
What are the three different types of muscle and where are they found?
Skeletal - body muscle (quadriceps, brisket)
Cardiac - heart
Smooth - internal organs (intestines, liver, spleen)
What are the segments of the small intestine? What are their functions?
Duodenum - primary site of digestion and begins absorption
Jejunum - Absorption
Ileum - Absorption
List the physiological differences between a monogastric and a ruminant stomach.
Ruminants have a stomach with four compartments: rumen, reticulum, omasum in addition to the abomasum ("true stomach"/ glandular stomach), that takes up a greater percentage of total GI tract capacity.
Monogastrics only have a glandular stomach that varies in size.
How is Total Digestible Energy (TDN) calculated?
TDN = (Gross Energy) - (Fecal Energy)
Define efficiency (address at least one factor that can effect efficiency). Which animal has the lowest efficiency (cattle, sheep, swine, broilers, fish)?
Efficiency in production is defined as units of input per unit output, factors can include body size, amount of movement an animal does to find food, digestive system, type of feed.
Cattle have the lowest efficiency (they require more feed per unit of gain) in the list.
How do you determine yield grade?
Beef yield grading uses adjusted fat thickness, % Kidney, pelvic and heart fat (KPH), and rib eye area to calculate the expected amount of closely trimmed retail cuts.
What are the products of fermentation?
VFAs, Gas (methane, CO2), Heat, Microbial crude protein, B Vitamins, and Vitamin K
Explain the process of rumination and eructation.
Rumination - Rechewing coarse material
• Steps in the process: Regurgitation, Remastication, Reensalivation, Reswallowing
• Reduces particle size and increases salivary flow
Eructation- Expelling gases produced from microbial fermentation
• Failure to expel gases = bloat
What are macro minerals? What are micro minerals? Give one example of both.
Macrominerals- minerals needed in large amounts
• examples: Ca, P, Na, Cl, S, Mg
Microminerals- minerals needed in small amounts (trace minerals)
• examples: I, Z, Mn, Co, Cu, Fe, Mo, Se, Fl
Explain how nutrition effects growth. Be sure to mention how it effects their growth curves.
High planes of nutrition allow the animal to reach its full growth potential during the growing stages, and increase fat deposition as an excess energy storage after basic needs and other growth have been met.
Low planes of nutrition over an extended period of time can limit the amount of growth an animal can have. It can decrease frame size and fat deposition. The animal may have trouble reaching sexual maturity at the same rate and reproducing.
Define Quality grade and give 2 examples of a grade.
Grade of meat based on amount of marbling (intramuscular fat) in the longissimus dorsi,
maturity of carcass, gender, meat and fat color.
Possible grades:
Young animal - Prime, Choice, Select, Standard
Old animal - Commercial, Utility, Cutter
What term is used to describe the isolated cellulose and lignin components of a roughage?
Acid Detergent Fiber (ADF): isolates the cellulose and lignin components of the roughage
-negatively correlated to digestibility of the feed
1. Selection - selecting food based on 5 senses and learned aversions
2. Prehension - The process of getting the food into the mouth
3. Mastication - chewing
4. Deglutition - swallowing
5. Digestion - physical changes: Chewing, swallowing, crushing, peristaltic motions. Chemical changes: enzymes, bacteria, microorganisms, digestive juices
6. Absorption - utilization of nutrients, crossing the epithelium and entering the blood.
7. Circulation - Transport of nutrients to site of storage and use, via blood or lymph
8. Metabolism - cell level utilization
9. Excretion - body voids material (through defecation, urination, exhalation, sweating, wearing off of cells)
What are the 6 classes of nutrients? What are their functions (give at least 1 of each)?
1. Water - nutrient transport, body temperature regulation, lubrication, maintenance of body fluids
2. Carbohydrates - supply energy
3. Protein - supply protein (amino acids)
4. Fats - supply energy
5. Minerals - structure and balance
6. Vitamins - catalysts and regulators