Pork Yield and Quality and Pork Carcass Evaluation

Key factors impacting pork yield and quality

Genetics, Nutrition, environment

Genetics

• Genotype

  • Genetic makeup of animal

  • Combined from sire and dam

• Phenotype

  • Observable characteristics

  • Influenced by both genotype and environment

  • P=G+E

Qualitative Traits

• Controlled by few pairs of genes

• Phenotypes are easily distinguished

• No environmental effect on phenotype

• No economic relevance in traits

  • Exception: Show pigs

Quantitative Traits

• Controlled by hundreds or thousands of genes

• Most econmically relevant traits

• Environment affects expression

• Ex. Days to 250, litter size, backfat, muscling

Heritability

• Terminal traits are typically more than 30%

• Days to 250-35%

• Feed efficiency-30%

• Backfat thickness-40%

How to improve terminal traits?

Selecting a boar that excels in these traits

Breeding value

Value of animal as genetic parents

Estimated Breeding Value (EBV)

Estimate of genotypic value an individual possesses

Expected progeny difference (EPD)

Advantage or disadvantage of an individual’s offspring over the progeny of an average animal

Positively Correlated Traits

Positive: When an increasse in one trait is made, the other trait increases as well

LEA to % lean

Negatively Correlated Traits

When an increase in one trait is made, the other trait decreases, greater muscle to poorer maternal performance

What traits should be selected?

Econmically relevant traits

• Number born alive

• Days to market weight

• Backfat

• Loin eye area

Most econmical cereal grain

• Corn

• Sorghum 

• Wheat

• Barley

• Oats

Good quality protein sources

• Soybean meal

• Canola meal

• Other oilseed-based meals

Corn

• Most used (most economical)

• Palatable and high energy density

• Low protein content, poor AA profile

• Deficient in lysine, tryptophan, threonine, and others

How to maximize cereal grain feeding value?

Ground or rolled, improves feed conversion

Protein

• Soybean meal

• Co-product of oil production

• Low fat content

• “Gold Standard” of high quality protein for pigs

• AA profile complements that of cereal grains

• Rich in lysine, threonine, and tryptophan

Vitamins and minerals

Salt, vitamins, and trace minerals are typically added into premix

Premix

Complete mix of vitamins, minerals, trace elements, and other nutritional additives to incorporate into feed

0.2%-8% of total mix depending on the type

4 environmental factors

Temperature, housing, biosecurity, care/welfare

Environment-Temperature

• Pigs are more sensitive to heat (can’t sweat)

• Ideal temp: 60-70F

Growing-finishing Pigs (temperature)-Heat stress

• Reduced feed intake

• Decreased ADG

• Decreased feed efficiency

Growing-finishing Pigs (temperature)-Cold Stress

• More energy diverted to keeping warm 

• Decreased feed efficiency

• Decreased gains

3 Different kinds of housing for finishing pigs

Indoor confinement buildings, hoop barns, outdoor lots

Indoor confinement buildings

• Intensive production

• Control on temperature, air quality, biosecurity

• Automated feed systems

• Slatted floors to allow for manure to fall through

Hoop barns

• Lower cost

• Deep bedding

• Allows for natural behaviors

Hoop barns vs. Confinement barns

• Similar growth rates

• Eat more → Less efficient

• Lower carcass lean

• Increased energy needed for heat production in winter

Outdoor lots

• Very low cost

• High labor requirements

• No climate control

• Installment of shelters

Outdoor lots vs other housing types

• Dirt and dust complicate disease control

• Require more feed per pound of grain

Biosecurity

Practices intended to protect animals against disease or harmful biological agents

Sick pigs

• Reduced appetite

• Reduced gains

• Increased treatment costs

• NOT EFFICIENT

Environmental enrichment

Adding some form of stimulation to a captive animal’s environment that improves the overall welfare of the animal

Mental and physical benefits to the animal

• Reduction in tail biting

• Improved disease resilience

• Improved human-animal relationship

  • Decreased stress

Growth enhancing technologies

• Not utilized in swine industry (beef)

• Ractopamine (Paylean) was a beta agonist utilized in swine

  • Shift nutrients from fat deposition to lean tissue deposition

• Approved for swine feed supplement in US but not globally

4 Factors of Pork Carcass Evaluation

• Trimness

• Muscling

• Quality Factors

• Carcass Weight

Which carcasses are best?

Trim+heavy muscle

Trimness

• Backfat

  • 10th rib

  • Last rib

Muscling

• LEA

• Visual shape of ham, loin, shoulder

• HEAVIER muscled carcass is desired

Primal cuts

Ham, loin, belly, boston butt, picnic

Lean cuts

Ham, loin, boston butt, picnic

Pork Carcass Evaluation

• Trimness, Muscling, Carcass weight

FFL # equation

9-(22*BF)+(3*LEA)+(0.463*HCW)

Pork Quality factors

Color, marbling, firmness

“Ideal” Pork Quality

• Greatest chance of good eating experience is in the middle

• Not too dark or light

• Not too soft or firm

RED, FIRM, NORMAL

• Red (reddish pink) color

• Firm texture

• Normal water loss

Pork Quality Defects-DARK, FIRM, DRY (DFD)

• Dark colored loin eyes not desirable to consumers

• Dry and firm to the touch

• Sticky surface

• High-water holding capacity

Pork Quality Defects-PSE

• Greater concern than DFD

• Less desirable product

• Low muscle pH

  • Buildup of lactic acid

• Shrinks excessively

Priorities for evaluating pork carcasses

• Trimmer, heavier muscled carcasses are best

• Fatter are not preferred

What is evaluated for trimness, muscling, and quality?

LEA and ventral side

How to rank carcasses if they are close on trimness?

Rank on muscle

What is not important for choosing ideal carcasses

Marbling

Rank the carcasses

From left to right

4, 1, 3, 2