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What is the goal of Animal Science?
To profitably satisfy the needs of humans for food, clothing, emotional well-being, shelter, fuel, etc.  
Biological Study of Livestock topics
Nutrition/metabolism Genetics/selection Reproduction/Physiology Growth and Development Production/Management  End Product 
Kingdom of Livestock
Phylum of Livestock
Have a backbone with a spinal cord
Class of Livestock
Order of Livestock
Even toed, hoofed, 4 toes
Family of Cattle, Sheep, and Goats
Multi-chambered stomachs, chew cud, ruminants, polycotyledonary placenta 
Cattle Scientific Name, Genus, & Species
SN: Bovine Genus: Bos  Species: Taurus, Indicus, Bison
Sheep Scientific Name, Genus, Species
SN: Ovine Genus: Ovis Species: Aries
Goat Scientific Name, Genus, Species
SN: Caprine Genus: Capra  Species: Hirius 
Swine Scientific Name, Family, Genus, Species
SN: Porcine  Family: Suidae  Genus: Sus Species: Scrota Domesticus
One Stomach 
Horse Scientific Name, Order, Family, Genus, Species
SN: equine Order: perissodactyla  Family: equidae  Genus: Equus Species: Callabus, asinus(donkey) 
non-reminant; odd number of toes
Chicken Scientific Name, Class, Order, Family, Genus, Species
SN: Gallus Gallus Domesticus Class: Aves  Order: Galliformes Family: Phasinanidae  Genus: Gallus Species: Domesticus 
Birds with wings and feathers
Short feet and beak
Ground dwelling birds; Exhibit Sexual Dimorphism
Intact Male Cattle (Young and Old)
Young: Bull Calf  Mature: Bull
How long does it take for a bull calf to mature?
1-2 years 
Castrated Cattle (Young and Old)
Young: Steer (Smaller body than Bull) Mature: Stag
Intact Swine (Young and Old)
Young: Boar Pigs  Mature: Boar
How long does it take for a boar pig to mature?
6-9 months 
Castrated Swine (young and old)
Young: Barrow Mature: Stag
Intact Sheep (young and old)
Young: Ram Lamb Mature: Ram/Buck
How long does it take a ram lamb to mature?
1 year
Castrated Sheep (young and old)
Young: wether  Mature: Stag
Intact Horse (Young and Old)
Young: Colt  Mature: Stud/Stallion
How long doe is take for a colt to mature?
2-3 years
Castrated Horse (young and old)
Young: Gelding  Mature: Gelding
Intact Goat (young and mature)
Young: Buck Mature: Buck
Castrated Goat (young and mature)
Young: Wether  Mature: Wether 
Intact Chicken (young and mature)
Young: cockerel  Mature: Rooster/Cock
Castrated Chicken (young and mature)
Young: Capon Mature: Capon 
Female Cattle (young and old)
Young: Heifer  Mature: Cow
How long does it take a heifer to mature?
2-3 years 
Cattle Meat Product (young and mature)
Young: Veal/ Calf  Mature: Beef 
Female Swine (young and mature)
Young: Gilt Mature: Sow 
How long does it take a gilt to mature?
1 year
Swine Meat Product (young and mature)
Young: Pork  Mature: Pork
Female Sheep (young and mature)
Young: ewe lamb  Mature: ewe
How long does it take for an ewe lamb to mature?
1 year 
Sheep Meat Product (young and mature)
Young: Lamb Mature: Mutton
Female Horse (young and mature)
Young: Filly  Mature: Mare
Horse Meat Product (young and mature)
Young: Horse Meat Mature: Horse Meat 
Female Chicken (young and old)
Young: Pullet Mature: Hen
Chicken Meat Product (young and mature)
Young: Chicken Mature: Chicken
Where does fresh beef come from?
Cattle 20 months old  Grain fed cattle  Fed corn and soymeal Designated for market
What becomes of non-fed cattle?
Roast Beef and Ground Beef Used in fast food restaurants 
What issues come with non-fed cattle?
Comes from older cows and bulls (3-8 years) Flavor issues  Fed grass instead of grain lower in fat, Lean tenderness issues 
What two categories do chickens fall under?
Egg Industry and Meat industry 
Free Martin
Mixed sex twins Mainly in Beef Cattle The female twin does not develop a regular reproductive system; goes straight to the beef market
List of Human Uses for Animal Products
Carcass Meat           Organ Meat Eggs  Milk Clothing  By-Products Pleasure  Power Manure  Research Models 
What part of the body is considered Carcass Meat?
What are examples of Organ meat?
Not consumed in the US  Chicken Gizzards Kidneys Tongue Liver Chitlins Heart
What are some clothing products that come from animal products?
Leather Hides  Wool Pelts
By-products produced from animal products?
Pharmaceuticals  Collagen Fat Animal Feed 
Types of Pharmaceuticals made from animal products?
Protein Hormones Insulin (Pigs) - not anymore
What is collagen and what is it used for?
Made from skin, hide, and feet Goes into food products: Jello Mayonnaise  Sausage Casing
What is animal fat used for?
Lubricants  Cosmetics Candles
Where are animals used mainly for pleasure?
Developed country such as the US 
Where are animals mainly used for power?
Undeveloped countries
What are uses of Manure and the two types of widely used manure?
Fertilizer  Energy  Buildings Chicken Manure and Cow Manure  Chicken manure is higher in Nitrogen and is more commonly used today
Research Models and their uses
Mainly baby pigs because of their close relation to handling diseases and boy set up  Up to 200 models of human diseases can be used and studied with animals 
World Population of Chickens
Worldwide: 20.7 1. China: 5.2 billion 2. US: 2.1 billion Products:  1. US: 17.1 billion Number one consumer: Hong Kong 
World Population of Cattle
Worldwide: 1.4 billion head 1. Brazil: 213 million 3. US: 93 million Meat Products:  1. US: 12 million Number one consumer: Argentina 
World Population of Sheep
Worldwide: 1.1 billion 1. China 139 billion Sheep Products 1. China: 2.1 million Number one consumer: Australia 
World Population of Swine
Worldwide: 967 million 1. China: 465 million 2. US: 66 million Pork Products:  1. China: 50.5 million 2. US 10.3 million Number one pork consumer: Denmark 
World Population of Dairy Cattle
Worldwide: 265 million 1. India: 44 million 4. US 9 million Dairy Products: 1. US: 89 million Number one consumer: Finland 
World population of Horses
Worldwide: 58.4 million 1. US: 10.2 million Horse Products:  1. China: 161 thousand 3. US: 28 thousand  Number one consumer: Italy
What is the importance of animal protein in a human diet?
Meat has a high "biological value" Amino acids, in the protein, match human requirements You digest muscle to gain muscle  All essential amino acids are present in the correct proportions  Animal products are an excellent source of B vitamins and THE ONLY source of vitamin B-12. 
What is the RDA of Calories and Protein?
Calories: 2700 (2000) Protein: 56 (44)
What are some health issues in developing countries?
Undernourishment  Malnutrition  Not getting enough nutrients  Less calorie and protein intake than RDA
Who consumes more animal products?
Developed countries (more intake of protein and calories)
What is the major difference between developed and developing countries?
Money and Mechanization  Money goes into purchasing of products needed to produce food and drought resistant crops  Mechanization helps people move away from agriculturally based jobs; more income 
About _% of the worlds tractors are in _.
20%  US
In 2005, how much of US population was fed by 2% of the population?
In 2005, one farmer fed how many US and world citizens?
US: 94 World: 34 Feeding whole communities now 
Who spends the least and the most amount of income on food?
Least: US - 10.9% Most: India - 51.4%
Reasons for inadequate food supplies in developing countries
Lack of knowledge  Population concentration  Lack of wealth  Governmental Policies Environmental Challenges Religious or social taboo
What is an example of inadequate population concentration?
Asia: 50% people to 22% agriculture 
What are examples of inadequate lack of wealth?
Can't afford new mechanization  Inability to increase production Can't afford fertilizer 
What are reasons lack of governmental support would hinder food supply?
No income from government: hindering the increase of production  Lack of government support  Lack of supplies 
What are examples of environmental challenges?
Lack of farmable land  Lack of rainfall Plant and animal diseases 
US Beef Cow Inventory
29.3 million 1. Texas 21. Georgia 
US Dairy Cow Inventory
9.2 million 1. California 25. Georgia 
US Hogs and Pigs Inventory
65.9 million 1. Iowa
US Breeding Sheep Inventory
4.0 million 1. Texas
US Broiler Inventory
8.6 billion 1. Georgia 
What breed of livestock does the US have the most of?
Chickens! Most widely consumed meat in the US 
US Horse Inventory
9.2 million 1. Texas
Breeds of Bos Taurus Beef Cattle
British  Angus    Hereford Shorthorn Exotic/Continental Simmental         Simangus: Simmental & angus Charolais           Limflex: Limousin & Angus Limousin            Balancer: Angus  Gelbvich Maine Anjou 
Breeds of Bos Indicus Beef Cattle
Zebu Brahman  Nellore Gir Indu-Brazil American Breeds Beef Master Brangus Braford Simbrah
What are the beef master cross breeds?
1/2 Brahman 1/4 Hereford 1/4 Shorthorn
What are the Brangus Crossbreeds?
5/8 Angus  3/8 Brahman
What are the Braford Crossbreeds?
5/8 Hereford 3/8 Brahman
What are the Simbrah Crossbreeds?
5/8 Simmental  3/8 Brahman
Originated in Scotland  Black Angus (#1 in US) Red Angus (#6) Polled Moderate Mature Size
Angus Strengths
Maternal Traits Fertility and calving ease Meat Quality - Marbling 
The fat located in the muscle  Adds flavor when cooked to eat (fat on a steak)
Angus Weaknesses
Small to moderate in size  Heat Tolerance Carcass cutability 
What is carcass cutability?
How much edible product you can get from the animal 
#2 in US  Originated in England Red body with white face  Black body with white face  Horned and polled  Moderate size
Hereford Strengths
Hardy: Range and cold  Productivity in range conditions Good temperament 
Hereford Weaknesses
Low milk production Moderate size  Susceptible to eye cancer: white face 
Red Angus 
Black Angus 
Originated in England  #10 in US Solid Red, Solid White or Roan (mix of red and white) Horned and Polled Moderate to large size
Shorthorn Strengths
Milk Production Carcass Quality  Mothering Ability Good Temperament 
Shorthorn Weaknesses
Lack of muscling Carcass cutability  Heat Tolerance: long, thick hair
Originated in France #3 in the US  Black, Reddish Brown Horned & polled
Limousin Strengths
Superior Muscling  Moderate to rapid growth Carcass Cutability 
Limousin Weaknesses
Fertility  Milk Production Carcass Quality 
Originated in Switzerland  #5 in US Black and Red  White Face Horned & polled  Large Mature Size 
Simmental Strengths
Milk production  Rapid Growth  Carcass Cutability 
Simmental Weaknesses
Mature Large size  Can cause "Dystocia"  Carcass quality 
Breeding with certain large cattle can cause birthing issues due to their large calf size 
What is the hottest bred cattle right now?
Simmental and Angus 
Originated in France  #4 in the US  Solid white to cream Horned and polled  Large mature size
Charolais Strengths
Muscling  Rapid Growth  Carcass cutability  
Charolais weaknesses
Cow maintenance costa Dystocia Milk production
Originated in Austria and Germany  #8 in the US Black and Golden Horned and polled Moderate mature size
Gelbvieh Strengths
Fertility/early maturity 
Issue with Gelbvieh early maturity
Cattle are usually weaned at 7 months, however the Gelbvieh, due to its early maturity, can become fertile and pregnant before they are weaned So, the Gelbvieh heifers and bull calves must be separated till weaned 
Gelbvieh weaknesses
Dystocia Marbling 
Originated in India  #11 in the US (on the decline) Gray to white (go from lighter to darker with age) Predominantly Horned Moderate mature size Large hump, loose skin, big/floppy ears
Brahman Strengths
Heat. insect, and disease tolerant  Mothering ability  Longevity  Rapid growth in crossbreeds 
What is important about Brahman mothering ability?
They are VERY protective over their babies  They form circles with their heads out and babies inside to protect them from danger and intruders  They will take someone down for coming near their babies
Why is Brahman longevity so great/not so great?
They live longer and are more productive later in life, however, they become fertile a year later than most cattle
Brahman Weaknesses
Lack of Muscle  Fertility/late sexual maturity  Cold Tolerance  Carcass quality and Tenderness
Why are Brahman on the decline in the US?
Their issues with carcass quality and tenderness of their meat 
Beef Master
Originated in the US  #7 in the US  Multi-colored  1/2 Brahman, 1/4 Hereford, 1/4 Shorthorn Predominantly Horned Moderate Mature Size
Beef Master Strengths
Heat Tolerance  Mothering ability  Performance on Forage 
Beef Master Weaknesses
Lack of Muscling  Variability in performance  With cross breeds: Some excel and some do not Carcass Cutability  Carcass quality and tenderness
Beef Master
Originated in US  # 9 in US  Black and Red (depending on the source of Angus) 5/8 Angus; 3/8 Brahman  Polled  Moderate mature size
Brangus Strengths
Heat Tolerance  Mothering Ability  Carcass Quality
Brangus Weaknesses
Muscling  Carcass Cutability  Temperament  Depends on cross; something wrong with genetics 
Tallest Breed in cattle  White color with black points 
Red-brown color 
Bos Taurus  Developed in the Virgin Islands Developed tropical adaptations such as heat tolerance Not great Carcass quality  Great tenderness Mother's milk too much; wasting energy and quality milk product
Santa Gertrudis
3/8 Brahman, 5/8 Shorthorn First of all American breeds developed  Developed in King Ranch  Not extremely popular today Muscle quality issue
3/8 Brahman, 5/8 Hereford Developed in SW Florida (Adam's Ranch)  Not popular due to carcass quality 
Santa Gertrudis 
Originated in Holland  Black and White; sometimes red and white  Large mature size (2200/1500) Make up 80% of our dairy cow industry 
What is significant about Holstein milk production?
They produce a very high yield (lbs/year) or lactation Have low milk fat: 3.7%  Does not exceed in milk quality 
What are some issues with large milk production?
Breakdown of utter Leg issues when on concrete a bunch  Breeding Issues 
Originated in Jersey Island  Fawn Color 
Brown Swiss
Switzerland Beef line called Bron Beef
Isle of Germany 
Milking Shorthorn
What are two important factors of the minor breeds of Dairy Cattle?
Pounds of milk and milk fat  Not a lot of influence 
Brown Swiss 
What is the main color of swine and why?
95% of pigs are white because the white hair comes off the hide easier 
Most of our pig production in the US is _. What does that mean?
Terminal  All slaughtered; Produced for the market 
There are not a lot of _ _ hogs today.
Pure Bred 
Maternal Breeds of Swine and important aspects
Yorkshire  Landrace Chester White  Meishan  Litter size Mothering Ability # of pigs per litter/# of litter per year Weaning weight  Structure/Skeleton (Will they survive?) Predominantly White 
#1 in the US England  White with red ears that stand up "Large White"  Over time developed the mother breed  10-14 pigs per litter
# 4 in the US  Denmark  Ears that flop down 10-14 pigs per litter 
Chester White
The Chester White is a breed of domestic pig which originated in Chester County, Pennsylvania. It was formerly known as the Chester County White.
Very different  Smaller and fatter Lots of interest in US due to its prolificacy  18-22 pigs per litter  Could not make meat profitable in US due to more fat than muscle 
Milking Shorthorn
Chester White 
Paternal Breeds and Important aspects
Duroc Hampshire  Pietran Spotted  Berkshire  Meat Quantity Muscling  Fat Growth Rate Feed efficiency 
# 2 in the US  Red  Large floppy ears  Know for growth and leanness
#3 in the US  Developed in Kentucky  Unique color: Black with white belt including two front legs  erect ears  Known for leanness
Known for extremely heavy muscle  Susceptible to stress  Impacts Quality of milk White with black spots  Erect ears 
Developed in India  Pink with large, dark spots 
Angus of swine breeds  Meat quality breed: Marbling  Black with white points: white legs and nose Produced in US for export  Not popular in US because there is no real profit in marbling in pork  NW part of US  Pure bred for specific market 
Ewe Breeds
Used specifically for wool market and lamb production Medium to fine wool Merino and Ramboulliet  Romney 
Ram Breeds
Used specifically for meat market  Suffolk  Hampshire Dorset Texel 
Merino & Ramboulliet
#4 in the US  Finest Wool Clothing  France 
Wool: Textile oriented  Large number of lambs 
#1 in the US England  Large  White with black legs and face  No wool on legs or head 
#3 in the US  Shorter than Suffolk with larger skeleton  England White body with black legs and face  Wool on legs and head 
#2 in US  Horned and Polled  England  All White 
Isle of the Netherlands  Known for muscle growth  Tan body with white legs and face 
Riding and Harness Breeds
American Quarter Horse American Saddle Horse  Arabian Morgan  Standardbred  Tennessee Walking Horse  Thoroughbred 
Pony Breeds
Shetland Pony of America  Welsh 
Color registries
Paint Pinto  Appaloosa  Buckskin  Palomino 
Draft Breeds
Clydesdale  Belgian Percheron
How much does 1 hand equal?
4 inches  Ground to withers(shoulders) 
American Quarter Horse
15.2 hands (62 inches (15*4+2)) US Great muscle development in hind legs  Racing  Moderate size
Throughbred ancestors
Darley Arabian Godolphin Arabian Byerly Turkey 
Kentucky Derby England Descendants of Arabia  Solid Colors: Beige, Brown, Chestnut  Long, tall, and lean  Built for endurance  16-16.2 hands 
Built for harness racing  Have to reach a certain time in racing to be named standardbred  Influences of Arabian  Moderate size Lean, long strides, not as much muscle as quarter horse (racing differences
Oldest Breed of horses 15 hands  Originated in Egypt: Deserts of Arabia  Pleasure Riding  Moderate Size  Very Showy (Dished face, raised tail, arched neck) Hyper
Warmblood Breeds
Bred for sporting events (Equestrian team)  Hanovarian  Trekenher 
Northern Germany  15 hands Good temperament: Calm and level-headed Good Stamina  Show horses  Great reliabilty
Prussia 16-17 hands  Used a lot in dressage Calm and level-headed 
What is dressage?
A horse competition where a horse completes a series of certain movements and tasks 
Spain Nezeperce Indians  3 color patterns: Blanket App (blanket over butt), Roan, and Leopard App (spots from front to back  Can also be registered as a quarter horse 
Golden horse (color of a 14kt US gold coin)  Primarily for pleasure 
Spain  White with brown splotches  Color patterns: Tobiano, Overo, Mix: Tovero, and Black & white  How much brown is on the horse decides what color pattern Not as muscular as paint; smaller 
Must be traced back to paint, thoroughbred, or quarterhorse to be registered as paint Body shape: Quarterhorse Color patterns: Tobian, Overo, Tovero, Black & white  Powerfully Built 
Clydesdale, Percheron, and Belgian
16-17 hands  Built VERY powerfully  Large feet  1600-2000 pounds 
Wales 11-13 hands 
Composition of lean muscle
70% water 20% protein 8% fat 1% Ash (Minerals)  <1% Carbs <1% Vitamins B and B-12
As an animal _, _ increases and _ and _ decrease.
fattens fat water  protien
Sacro- or Mayo-
Means muscle 
3 types of muscle
Skeletal Cardiac Smooth Muscle 
Skeletal Muscle
Attached to skeleton  Voluntarily controlled by sympathetic nervous system Striated to bring about force and movement of skeleton
Cardiac Muscle
Heart Muscle  Involuntarily controlled by unsympathetic nervous system  Striated to pump blood 
Smooth Muscle
GI and Repro Tract  Circulatory System  Involuntarily controlled by the unsympathetic nervous system 
Sarcoplasmic Protiens
Water soluble  Myoglobin hemoglobin  cytochromes enzymes associated with energy pathways 
The Major meat pigment  Exists in 3 forms in fresh meat  1. Deoymyglobin: w/o oxygen 2. Oxymyglobin: w/ oxygen  3. Metmyglobin 
Two main parts of myglobin
Heme ring and globin  Iron in blood Ring with protein molecule in middle/protein around ring 
Two factors that determine color
Chemical state of Iron Reduced: Fe2+ Oxidized: Fe3+  Compound bound to myglobins free binding site 
American Quarter Horse
Tennessee Walking Horse
Pony of America 
What must the compound bound to the myoglobin free binding site have?
Water  The pigment of the meat will be purple with water present 
Number one component of lean muscle
Heme Ring
Contains Iron  Has 4 binding sites
The protein component  Has 2 binding sites 
Purple  Water is present  Means without oxygen
Bright red  Means with oxygen
Brown  End of shelf-life  Prevents binding sites
Why is it better to buy purple meat?
You want to buy purple meat instead of red so you can prevent oxidation from occurring, causing the meat to spoil. (metmyoglobin) 
Why do you want to keep oxygen out of meat packaging?
Vacuum packaged meat lasts a  long time when frozen  Has a 60-90 day shelf-life when not frozen Water and myoglobin is the liquid at the bottom of the packaged meat 
Why is meat brown when cooked well?
You have denatured the myoglobin Cooking does not produce myoglobin, it denatures it 
Cured Meats
Nitrite reacts with myoglobin and forms a pink color  Nitrite turns to a form of nitric oxide and converts to another pigment of myoglobin Small amount added  Pink when fully cooked (ex. hot dogs)  Color lasts a long time Heat sets the color in 
In Order from left, to top, to bottom Deoxymyoglobin Oxymyoglobin Metmyoglobin Reversible reactions  When meat moved from metmyoglobin to deoxymyoglobin color will change, but shelf-life will still be short 
What are good reducing agents?
Vitamin E and C 
Ways to extend shelf- life
Enter Carbon Monoxide, a small amount, you get a bright cherry red color  CO2 stays longer and color stays longer, but could go past its shelf-life  Due to controversy = not used in today's industry  Feed animal vitamin E in high concentrations to increase reducing potential  Stays re…
Ways to know if a meat is past its shelf-life
Odor  Expiration Date  Not a lot of leeway on the end of shelf life of meat 
Bacteria and Meat
Most bacteria comes from handling  Inside of meat is aescptic until cut and then handled  When ground (ground beef), bacteria is easily attained  Heat added to kill bacteria increase oxidation rate 
Three classes of muscle protein
In order of most soluble to least soluble:  Sarcoplasmic Proteins (water soluble)  Myofibrillar Protiens (salt soluble) Stromal or connected tissue proteins (acid soluble) 
How to move from metmyoglobin to oxymyoglobin
Feed animal vitamin E in high concentrations and increase the reducing potential  Stays redder longer Vitamin E is fat soluble in the membranes of the muscle cells and helps enhance shelf-life maybe a day or two 
Myofibrillar Proteins
Salt soluble  Myosin and actin main contractile proteins  Troponin and Tropomayasin main regulatory proteins 
Myosin and Actin
Make up 75% of the contractile proteins Muscle Contraction in meat 
Tropoin and Tropomayasin
Regulate the actin and myosin in muscle contraction Each make-up 5% of the myofibrillar proteins  10% protein 
Stromal or Connected tissue
Acid soluble  Connects and holds parts of the body down  Attaches skin, hide, protects against infections, important in wound healing 
Collagen Protein
Major connective tissue protein in the body  Highly ordered structure Complex protein  25-30% of weight White color Tensile strength 
Yellow Color Very strong - elastic  Mainly in tendons and ligaments 
Muscle Fat
About 50% of dietary energy from meat comes from fat  Animal fat is highly digestible  Much of the meat flavor comes from fats (carbonyl compounds) 
Animal fat saturation
Animal fat is generally more saturated than plants Solid at room temperature  Order of saturation: Pork < Beef < Lamb Pork is the least saturated due to monogastric  Beef and lamb are both ruminants; when they eat unsaturated fat it turns into saturated fat 
What type of fats are we supposed to consume?
How does dietary fat influence monogastric systems?
Dietary fat can influence the saturation level of carcass fat  Carcass meat can get soft and oily 
T/F: Meats are typically a high source of lipids.
FALSE Are not a high source 
Eat less ___ and more ____ and _____.
Fat Fruits Vegetables 
One 3oz. serving of meat provides:
10% calories 40% protein 16% iron 35% zinc 40% B-vitamins 3oz. is the size of a deck of cards 
Actual amount of intake of dairy products today:
3 servings 
Actual amount of intake of fats and oils today:
3 1/2 servings 
Actual amount of intake of meats today:
2.2 servings
Actual amount of intake of vegetables today:
2 servings 
Actual amount of intake of fruit today:
1 serving 
Actual intake of breads today:
5.1 servings 
Meat Protein biological value
Have all of the essential amino acids in the correct proportions  The amino acids we can't make, we have to intake 
Factors affecting consumer acceptability:
Flavor Appearance  Tenderness  Smell  Price 
3 factors that impact tenderness
Myofibrillar Proteins  Connective Tissue Marbling 
Myofibrillar proteins affecting tenderness
Contractile proteins  Contraction due to rigor causes toughness  Aging caused increased tenderness  Muscle enzymes break down and loosens structure  14-21 days of aging to optimize tenderness 
Stiffening due to death of muscle 
Connective tissue affecting tenderness
Mainly collagen  The more connective tissues: the loco motor muscles improve
As an animal ages, solubility decreases 
Marbling affecting tenderness
Lubrication  Fat stimulates salvation which eases chewing  Dilution Fat dilutes the negative myofibrillar and connective tissue effects on tenderness 
Methods for improving tenderness
Electrical Stimulation  Aging  Marinating  Tenderizers Mechanical tenderization  Proper cooking 
Electrical Stimulation
60-500 volts  Speeds rigor formation  Blocks cold shortening  Causes pH decline  Physical disruption  Makes the muscle contract  Causes rigor to happen before temperature drops and keeps rigor from toughening muscle so much 
Acid solutions to solubilize connective tissue  Vinegar and Lemon Juice 
Papain (papaya)  Ficin (fig) Bromelin (pineapple juice)  If you leave fro too long, it will break down everything and it will become mushy  CaCl2, NaCl, PO4
Mechanical Tenderization
Needle or blaze tenderizers  Allows bacteria to get into meat 
Proper Cooking
Low temperature, long time  Solubilizes collagen 
Refers to the fluid retention during cooking 
3 factors that impact juiciness
Marbling  Cooking Method  Added Moisture: "enhancement" 
Marbling and Juiciness
Intramuscular fat contributes to juiciness 
Cooking Method and Juiciness
Rapid heat seals in moisture  Searing or Broiling  "sealing the surface"
Added moisture: "enhancement"
Added liquid and salt Most pork today is enhanced Low fat leads to less flavor, so must enhance 
Flavor and Aroma
Protein: gives the meat flavor  nitrogenous compounds  Fat: gives the species flavor  Beef, pork, or lamb Carbonyl compounds 
Appearance of meat
HUGE factor at "point of purchase" Color (uniformity and correctness)  Firmness Texture  pH related issues: normal pH of meat 5.6
"Dark, firm, and Dry (DFD)"
Predominantly in beef  Results from pH >6.0 Long term stress Low muscle glycogen at slaughter 
"Pale, soft, and exudative (PSE)"
Results from low pH: <5.4  Short term prior to slaughter  Seeing PSE characteristics in chickens 
Dressage Percentage Calculation:
Hot carcass weight / live weight x 100% 
General Ranges of Dressage Percentages:
Pork DP: 70% Beef  60% Sheep 50% 
The more ___ you produce, the more ____ you earn.
Pounds  Money 
Factors affecting dressage percentage
Fill Content of the GI tract at slaughter - higher DP  Weight can increase DP  Finish (fatness): fatter animals have higher DP  Hide, head, and feet weight  Leave hide on, take hair off 
Beef carcass grading
Evaluated between the 12th and 13th ribs  Splits carcass in half  Leaves in a rib in the back in case you need to hang it  Why split in half?  Because its HEAVY Don't have to with sheep and pigs cause they are smaller in size  Gives a good grading spot  Good estimate of fat and mus…
Two types of grading
Yield grade Quality Grade 
Yield Grade
1-5 (1 good - 5 bad)  % boneless closely-trimmed retail product from chuck, round, rib,and loin 12th rib back fat : inch  Ribeye area: inch squared  Kidney, Pelvic, and heart fat (% of carcass weight)  Hot carcass weight, pounds 
Quality Grade
Prime Choice, Select, Standard  Maturity (A to E): bone size, shape, ossification  Marbling Score: intramuscular fat content 
What is the largest production cost in the livestock industry?
Feed costs (60-70%)

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