meat production 2

dressing percentage is the

ratio of dressed carcass weight to live carcass weight

how do you calculate DP

hot carcass weight / live weight x 100

what is fed cattle DP

63%

what are cull cows DP

40-55

what is a market hogs DP

72%

what is a market lambs dressing percent

52

what would the carcass weight of a 1000 lb steer be

1000 x .63 = 630

why is there variation of DP values between species

weight of hide, head and skin left on hog, intestinal content, difference in muscle mass

if you can sell a beef carcass for 200 cwt how much should you pay for the live cow

200 x .63 = $126

humane methods of slaughter act was meant to

provide safer conditions for animals

who was exempt from the humane methods of slaughter act

religious ritualistic slaughter like kosher or halal

what are some conditions of humane slaughter act

prods under 50v, disabled animals must not be dragged new law states that no downers enter plants, must have water in holding pens if held over 24 hours, approved stunning methods before slaughtering

pre-slaughter management of livestock includes

animals free from stress, fear, pain, have access to water and 12-24 hour fast

why must animals have a 12-24 hour fast before slaughter

it makes evisceration easier and there is less food in GI tract that can be ruptured and touch meat

feed withdrawals reduce

transport weight, fuel cost, contamination, BSE

downer animals should not

enter the human food chain

non-ambulatory (downer) animals are

condembed to prevent BSE from entering food supply

BSE stands for

bovine spongiform encephalopathy

what kind of non-ambulatory animals can still be inspected to enter food supply

hogs, chicken, sheep, veal

stunning

comatize, NOT kill, breathing and heart beat are continued

mechanical stunning

concussion or penetration

mechanical stunning is used on

cattle and sheep

chemical stunning

carbo dioxide is the only approved substance for this

what animals can have chemical stunning

hogs and chickens

electrical stunning

uses various voltages and amps and time parameters

electrical stunning is used on

hogs and chickens

what is the first step in the harvesting process

stunning to make them insensible to pain

most plants use a

captive bolt similar to a firearm

large animals such as cattle are often

restrained for mechanical stunning in a stunning or knock box

CO2 has become popularized in

swine to improve product quality, color, and reduced wateriness

what is the second step in the slaughter process

exsanguination (bleeding)

during exsanguination, the

carotid arteries and jugular veins are cut at the bast of the neck where it joins the sternum

shoulder stick occurs when

the process is done incorrectly and results in blood spots and clots in some shoulder muscles

why is a thorough bleeding critical

because blood is a medium for bacteria and it is undesirable to consumers

product blemishes and blood spots and broken backs are a result of

extended time between stunning and bleeding

cattle and sheep are

skinned to remove hide and hair

poultry and pigs are

scalded to remove only hair or feathers

how does scalding pigs work

pigs are placed in 140 degree water for 5-8 minutes to release hair follicles and are then tumbled

poultry scalding uses

125-130 degree water for 60-120 seconds

what are the steps in order of the slaughter process

stunned, shackled, bleeding, dehair/skin, gambreling, evisceration, carcass manipulation

evisceration is the

removal of internal organs from abdominal cavity

why is evisceration the most important step

because this is commonly where contamination happens so both ends must be tied off to minimize contamination

why should evisceration be done with caution

because the GI tract harbors lots of microorganisms that can cause meat spoilage

gambrelling

animals are hung on a rail by back legs

carcass manipulation includes

caul fat removed from pig intestines and cattle and pig carcasses are split down the middle with a saw through vertebral column

after carcass splitting,

trimming of any contamination or tissue with excessive hemorrhages is done

cattle spinal cords are

removed as a precautionary measure against spread of BSE and carcass is washed to remove bone fragments and blood

what are some antimicrobial interventions

steam vacuum, hot water rinse, organic acid rinses

steam vacuums are

handheld and use hot water spray

a hot water rinse uses

160 or less degree water for beef and pork to reduce salmonella or ecoli

organic acid rinses are done on the

entire carcass to remove bacteria and these rinses can be lactic or acetic acid like vinegar

what is the last step of the slaughter process

USDA inspection

what are some meat preserving methods

drying, freezing, salting, smoking

salting started with

sumerians 5000 years ago

smoking was likely developed by

primitive tribes who lives in caves that burned fires for warmth and smoked meat inadvertently

how did meat preservation develop through the years

it started out being unevenly cured, dried, too slaty, or too heavily smoked, then the process became perfected

nitrate is

NO3

nitrates are a

preservative found in hot dogs, bacon, bologna, salami, deli meats

what is the purpose of nitrates

preserve color and prevent growth of botulism bacteria

nitrates add to the

cured flavor

nitrates NO3 can be harmless but when broken down

into NO2 nitrites

nitrites can

speed up curing (not cooking)

why shouldnt you consume too many nitrates

they break down into nitrosamines - a carcinogen

the food safety and inspection service must

regulate the amount of nitrates added to food

salt, sugar, nitrate, nitrites get added to food for

preservation, flavor, color

salt enhances

flavor, preservatives, dehydrates meat through osmosis

sugars are added to meat for

flavor, counteract salt, provide energy for bacteria that convert nitrate to nitrite, lowers pH

nitrates or nitrites are added for

flavor, prevents “warmed-over” flavor, slow rancidity, slows botulism growth, contributes to pink color

HACCP

hazard analysis critical control points is implemented by the USDA

HACCP has

written plans for inspecting meat during harvesting and production phases and testing for pathogens

HACCP forces processors and packers to focus their efforts on

reducing pathogens in the food production chain

the color of cured meats results from the combo of

the mscle pigment, myoglobin, and nitric oxide

myoglobin is a

purplish red

nitric oxide is generated from

nitrate/nitrite

nitric oxide myoglobin is

red

when you mix nitric oxide myoglobin with heat you get

nitrosyl hemochromogen which is a cured pink

what other curing ingredients are there

ascorbic acid, alkaline phosphates, water

ascorbic acid is added for

color

alkaline phosphates are added to

decrease shrinkage from water loss

dry curing

salting with curing mixture

wet curing can be

spray pumping, stitch pumping, immersion curing

combination curing

dry + immersion, spray + stitch immersion

dry curing is the

original and oldest way of curing meats where the curing agents are only on the surface

advantages of dry curing

flavor and texture, no equipment, drier product so no fridge, surface bacteria minimal

disadvantages of salt curing

slower, shrinkage, rancidity, very salty

injection curing

goes directly into meats via probes or injection via brachial or femoral arteries

3 forms of injection curing

stitch pumping, artery injection, machine injection

stich pumping

long needle with multiple holes

artery or spray pumping

large needle with one hole

machine injection or immersion curing

machine with multiple needles that inject automatically

advantages of injection curing

rapid penetration, reduces spoilage, reduced shrink

disadvantages of injection curing

rapidness causes diminished flavor profile, texture is different

combination curing is good for when

a dry product is desired but internal spoilage must be prevented

massaging and tumbling is used to

diffuse and bind curing ingredients

tumbling is the

gravitational impact of meat dropping from top to bottom in a rotating drum

tumbling impact extracts

proteins from muscle

massaging is the

abrasion of meat against other meat or paddles

the frictional energy from massaging

extracts proteins from muscle while minimizing muscle tearing

why protein extraction?

hastens curing, allows for moisture retention, binds meat together

curing time is variable depending on

product size, temp of storage, curing method used