Exam 2 Flashcards
Adaptation
long term changes in animals in response to their environment that are genetically based (long change)
Acclimation
the process or result of becoming accustomed to a new climate or to new conditions (short change)
Critical temperature
the temperature below (lower critical temperature) which the animal must make physiological adjustments to maintain its body temperature. Upper critical temperature is that temperature at which the animal makes adjustments to try and cool its body.
Effective Temperature
the total heating and cooling power of the environment
Evaporation
loss of heat through vaporization of moisture from the respiratory tract and skin
Homeotherm
animals that maintain a relatively constant body temperature regardless of external temperatures
Farm Animal temps: Horses, cattle, goats, sheep, swine, chickens
Horse: 100
Cattle: 101.5
Goats & Sheep: 102
Swine: 102.5
Chickens: 107
Radiation
the exchange of heat between two objects that are not touching. Can result in loss or gain of heat.
Thermoneutral Zone
range of temperatures where heat loss and heat production are about the same. Animal is in comfort zone- no physiological response to temperature
Factors affecting critical temperature
Haircoat, subcutaneous fat, nutritional level, animal wet or dry
Thyroxine
produced by the thyroid gland, thyroxine secretion increases during cold stress and decreases during heat stress
Corticoids
produced by the adrenal gland, cortical secretions increased during cold sorters and decreased during heat stress
How do summer months affect livestock?
summer months are typically more limiting to livestock production because most of the farm animals are not well adapted to dissipating heat. Rate of gain decreases. Exception- Brahman
Shade
the cheapest and simplest method of reducing heat stress due to solar radiation, can reduce radiant heat gain up to 50%
Evaporative Cooling
one of the most effective ways to control heat stress, particularly in swine. include sprinklers, foggers, and wallows. Popular in poultry houses.
Refrigeration
refrigerated air conditioning is prohibitive in terms of cost. Can cool air down to the mid 60’s
Zone Cooling
blowing air onto the head has been effective in sows in farrowing houses
Why is Ventilation important?
need proper air movement in enclosed, confinement buildings. Moisture must be removed from the air along with ammonia. Also important for temperature control. Prevents pneumonia issues.
Why are wind breaks and shelters important?
reduce the effects of wind chill, block cold northerly wind
What are the ration adjustments during temperature stress?
increases in energy required to maintain body temperature result in decreased feed efficiency. Feed and water needs change during stress. Water intake during heavy stress increased 50- 100%
What contributes to heat stress?
high fiber diets, feed higher fiber diets during cold stress
How does light affect animal performance?
day length is associated with reproductive performance in a number of species. Also associated with hair growth.
What is one of the major problems livestock producers face today?
management of waste
methane production
fiber re-feeding
Healthy
free of disease
Disease
state other than complete wellness
Clinical signs
outward appearance or symptom that is not normal
Pathology
study of the essential nature of diseases
Etiology
the cause of disease or the study of the causes of disease
Requirements of an infectious disease (4)
- organism must be able to enter body of host
- must be able to adapt to host environment and reproduce
- must be able to exit body
- complete cycle by attacking another host
Immune system
the bodies ability to prevent sickness
What are the levels of protection the body has? (immune system)
skin, lining of GI tract, antibody production
Antibodies
protein molecules that are able to recognize harmful organisms and prevent them from harming the body
Passive Immunity
passed from mother to offspring during gestation or from colostrum
What type of immunity is passive immunity?
short term immunity and protection from organisms the dam was exposed to
Active Immunity
when antibodies are produced by the animal from exposure to an organism or vaccination
What are the operation health programs?
management
nutrition
genetics
isolation/ quarantine
animal identification
quickly identify sick animals
Prevention & Management
Operation health programs- nutrition
balanced rations, proper body condition score, clean water, reduce metabolic problems
Operation health programs- genetics
eliminate animals with problems
operation health programs- isolation/quarantine
separate new animals for 6-8 weeks, test animals for any disease, perform soundness exams on horses
Operation health programs- animal identification
traceability of animal, good record keeping
Operation health programs- quickly identify sick animals
quarantine if necessary, diagnose, treat, document treatment, identify cause of sickness
What species is affected by Caseous Lymphadenitis (CL)?
Sheep and goats
Zoonotic disease
a disease that can pass between animals and humans
Examples of zoonotic diseases
rabies, ringworm, Q-fever, brucellosis, tuberculosis, toxoplasmosis
What meat product is effected by Trichinosis?
Pig meat/ Pork
What is USDA’s inspection programs called? (Animal health and welfare)
Animal and plant health inspection service (APHIS)
-protects and promotes U.S. agriculture: animal welfare, customs, emergency management, and homeland security
National Animal identification system
-trace back program to quickly identify and trace sick animals
What are market classes and grades used for?
designed to “accurately” describe livestock that are being sold around the country
-type, prices, trends
-makes sales understandable by all parties
-case ready products (we buy parts)
Market classes
groups of animals separated according to use
-slaughter
-feeder
-bred heifers
-pairs
Subclasses
-age
-sex
-weight
Grades
designed to group animals according to relative merit within a market class
-quality denotes eating quality “palatability”
-cutabiloity refers to leanness or trimness
Grades
What grades do we give slaughter animals?
designed to group animals according to relative merit within a market class
-quality denotes eating quality, “palatability.”
-cutability refers to leanness or trimness
USDA inspection vs. USDA grades
USDA inspection is mandatory while USDA grades are voluntary (some packers have their own standards)
How do we grade feeder cattle?
On frame size and muscle thickness
How much do large frame cattle have to weigh to grade choice?
Steer: 1250 lbs or greater
Heifer: 1150 lbs or greater
How much do medium frame cattle have to weigh to grade choice?
Steer: 1100-1250 lbs
Heifer: 1000-1150 lbs
How much do small frame cattle have to weigh to grade choice?
Steer: less than 1100 lbs
Heifer: 1000 lbs
Dressing percentage Equation
carcass weight / live weight x 100
What factors influence dressing percentage?
fill, when fat increases DP also increases, when muscle increases DP also increases, mud
Dressing percentages of hog, lamb and cattle?
hog: 70%
lamb: 50%
cattle: 60%
Purpose of beef grading?
to sort carcasses from large, heterogeneous groups into smaller, homogenous groups of similar sex
Beef yield grading
an estimate of the yield of boneless, closely-trimmed retail cuts from the round, loin, rib and chuck
Range of beef yield grades
1.0-5.9
Factors evaluated in yield grading (4)
and their averages
- carcass weight- 600 lbs
- fat thickness- benchmark preliminary yield grade
- ribeye area- 11.0 sq. in
- kidney, pelvic, and heart fat -waste 5%
Beef yield grading- amount of external fat
measured 3/4 of the way up the ribeye perpendicular to the chine bone, preliminary yield grade (PYG)
Beef yield grading- amount of kidney, pelvic and heart fat (KPH)
% of carcass weight
as the amount of KPH increases, the percentage of retail cuts decreases
Beef yield grading- ribeye area
(Longissimus dorsi) measured in sq. inches (.10)
- between 12th and 13th rib interface
- an increase in ribeye area (REA) indicates and increase in the percentage of retail cuts
Factors to determine Beef yield grades
-BEEF- estimate of % boneless, closely trimmed retail cuts from the round, loin, rib, and chuck (avg. is 60% of live weight)
-Adj. Fat Thickness- split between the 12th & 13th rib ~.6”
-Rib eye area- Longissimus dorsi muscle ~ 11.0”
-% KPH (kideney, pelvic, and heart fat) ~ 1-6%
-Carcass weight ~ 600 lbs average
What is beef quality grading?
a composite evaluation of factors that affect the palatability of meat, using carcass measurements to predict palatability of carcass
-tenderness
-juiciness
-flavor
What is beef quality grading based on?
carcass maturity & degree of marbling
Beef Skeletal maturity (age)
A- 9-30 months
B- 30-42
Big difference in flavor, can’t grade choice below line
C- 42-72
D-72-96
E- younger than 96 months
How do you check maturity of a beef carcass?
Vertebral Column Classification
-Sacral vertebrae
-Lumbar vertebrae
-Thoracic vertebrae
Condition of bones
-size and shape of rib bones
-young: red and round
-Old: white, wide and flat
What additional factors affect quality grades in beef?
not good marbling, dark cutter, dark red spots (ruptured capillaries)
What is lamb grading used for?
used to sort lamb carcasses into homogeneous groups to facilitate marketing
-sorted within sex classes
Sex determination in lamb grading
Ewes have udder fat that appears smooth, wethers have cod fat that appears rough
How does the USDA grade lamb carcasses?
-Quality grades predict the tenderness, juiciness and flavor of the cooked product
-yield grades predict cutability or percentage of semi-boneless, closely trimmed retail cuts
How are lamb quality grades determined?
-maturity
-fat streaking in the flank
-firmness of the lean
- conformation
What are the lamb quality grades?
prime, choice, good, utility
How is lamb carcass maturity determined? What are the maturity classes?
-condition of the trotter
-shape of the ribs
-color of the lean
-texture of the lean
lamb, yearling mutton, mutton
Lamb grading maturity (months)
Lamb (A): 3-8 months
Lamb (B): 8-14 months
Yearling mutton: 14-24 months
Mutton: over 24 months
What age lamb would have a break joint?
lamb
What age lamb would have a spool joint?
mutton
Lamb quality grade- conformation
evaluated as carcass width in relation to carcass length and includes acceptable fat
Why do hair sheep taste different than wool sheep?
they don’t produce lanolin
Lamb yield grading
used to predict the percent of semi-boneless, closely trimmed retail cuts from the leg, loin, rack and shoulder
What are lamb yield grades based on? What are the USDA yield grades for lamb carcasses?
-external fat measured opposite the ribeye at the 12th rib
-1,2,3,4,5
Lamb yield grade equation
0.4 + (10 x fat thickness, in)
Pork grading
developed by USDA to provide segregation according to class, as determined by the apparent sex condition of the animal at the time of slaughter, and grade, which reflects the quality of pork and the relative proportion of lean cuts to fat cuts in the carcass
Classes of pork carcasses (5)
-barrow
-gilt
-sow
-stag
-boar
USDA pig grades are based on what 2 factors?
- quality- indicating characteristics of the lean
-expected combined yields of the four lean cuts: ham, loin, Boston butt, picnic shoulder
Factors assessed to determine pig carcass quality (4)
-firmness of fat and lean: at least slightly firm
-color of lean: grayish pick to moderately dark red
-amount of feathering: at least slight
-belly thickness: at least slightly thick, 0.6 inches
Pork Bipartite system
U.S. 1, 2, 3, 4
-pork meets minimum requirements
U.S. Utility
-unacceptable: soft fat or lean, pale or dark lean color, thin/soft bellies
What is cutability? (pork)
cutability is based on the percentage yield of bone-in, closely trimmed four lean cuts
Factors used to assign USDA pork cutability grades:
- fat opposite the last rib or last rib backfat thickness
-muscling score
USDA grade based on last rib backfat (pork)
U.S. 1, 2, 3, 4
1: less than 1 in
2: 1-1.24
3: 1.25-1.49
4: 1.50 inches or greater
USDA pork cutability grade equation
(4 x last rib backfat thickness, in) - ( 1.0 x muscle score)
Muscling scores:
thin= 1
average= 2
thick= 3
Poultry grading
“A” quality- free of deformities
-well developed covering of flesh( no tears)
-well developed layer of fat
-no feathers
-no broken bones
“B” quality- slight deformities
-moderate deformities
-moderate covering of skin and fat
-occasional pinfeather
-disjointed bones but no broken
Meat protein color in cattle, lamb and pork
cattle: cherry red
Lamb: light red
pork: pink
What color does protein turn after death?
purple color becomes species specific due to final pH level
What happens to animal’s blood and oxygen after death? Hemoglobin? Myoglobin?
-Glycogen becomes lactic acid
-Hemoglobin: transports oxygen from the lungs to the muscles
-Myoglobin: stores oxygen (color determining)
What is muscle color correlated to?
dircetly correlated to the acidicity or pH level of the meat and signals the water holding capacity of the meat
What happens to pH level after death? Ideal pH?
pH level drops due to lactic acid content
Ideal pH: 5.6
What type of marketing is used in poultry and swine industries?
Vertical integration- when all steps of production are owned by a single owner or controller by one company
Natural vs. organic
Natural-minimally processed and contain no artificial ingredients, only applies to processing of meat and egg products
Organic- food has 95% or more organic content, come from animals that are given no antibiotics or growth hormones
Grass fed
receive a majority of their nutrients from grass throughout their life, while organic animals may also be supplemented with grain
Governments role in food safety
to regulate producers in order to provide a safe, wholesome, environmentally friendly product tailored to the consumer’s wants and needs
Hazard Analysis and critical control points- HACCP
systematic preventative approach to food safety that identifies physical, chemical, and biological hazards in production processes that can cause the finished product to be unsafe
-reduces risks to a safe level
-EVERY PROCESSING PLANT MUST HAVE A HACCP PLAN THAT IS SPECIFICALLY DESIGNED FOR THAT PLANT
Inspection
completed by an inspector who provided the first line of defense against adultured meat and poultry products. They are responsible inspection of animals before and after slughter.
Grading
determination of a quality grade through a composite evaluation of carcass maturity, firmness, texture, color of lean, and the amount and distribution of marbling within the lean
By-product percentages of hogs, cattle and sheep
hogs: 7%
cattle: 13%
sheep: 9-12%
Aging beef
-can be aged for up to 11 days
-gives a stronger flavor
-30-35 F
-must be in a clean high humidity environment
-usually with high quality carcasses
Genotype
Animal’s blueprint
Chromosome
large molecule containing DNA, made of genes
Gene
segment of chromosome composed of DNA
DNA
two strands of sugar-phosphate backbone with bridges of nitrogen bases
Nucleotide
sugar, phosphate, and one of the 4 nitrogen bases
Expression of genes
select genes that return US dollars
Inheritance
passing traits from parent to offspring
Alleles
alternate forms of a gene that affect the same trait
Gametes
reproductive cells and carry half of the parent’s genetic code(A or a)
Codominance
both alleles expressed
Incomplete dominance
intermediate, no dominance
Sex- influenced
phenotype expressed differently between sexes
-dominance differs between sexes
Sex- limited
traits unique to one sex, both sexes carry the genes but only one capable of expressing
Sex-linked
genes found only on X or Y chromosome
Selection
determining which individuals reproduce
Qualitative
classified in groups
Quantitative
numerically measured
Heritability
impact of additive genes
Factors in calculating heritability
-selection differential
-heritability of trait- & expected to be inherited
highly-carcass merit traits, moderately-growth, lowly- reproductive
Imbreeding
mating closely related individuals
-decreases variation
Linebreeding
form of inbreeding using repeated crossings to ancestors
Outbreeding
mating less closely related animals than the general population
Crossbreeding
to use complementarity of traits, mating of two individuals from different breeds
- want offspring to outperform parents
Breeding value
estimated value of an individual as a parent
-based on performance of individual and close relatives
Expected progeny difference (EPD)
predicted difference in performance between individual offspring and offsprings contemporary group
-useful for comparison within breed or group
EPDs include:
Birth, growth, maternal, terminal, reproduction, behavior
