livestock lab

Breeding animal

An animal retained in a livestock herd or flock specifically for reproduction to perpetuate desirable genetic traits.

Market animal

A terminal livestock animal raised specifically for meat production and human consumption.

Feeder animal

A young, lightweight livestock animal purchased to be fed and finished prior to market harvest.

Hybrid vigor (Heterosis)

The tendency of crossbred offspring to show superior performance or traits compared to the average of their purebred parents.

Maternal traits

Heritable characteristics in livestock that influence mothering ability, milk production, and litter size.

Terminal traits

Heritable characteristics focused on market performance, such as growth rate, muscle mass, and carcass fat composition.

Marbling

The intramuscular fat flecks interspersed within lean muscle tissue that enhance meat tenderness, juiciness, and flavor.

USDA Yield Grade

A numeric score representing the expected percentage of trimmed lean muscle yield from a livestock carcass.

Gilt

A young female swine that has not yet given birth to a litter.

Sow

A mature female swine that has given birth.

Barrow

A male swine that was castrated before reaching sexual maturity.

Boar

An intact, uncastrated male swine used primarily for breeding.

Farrowing

The act of giving birth in swine species.

Swine gestation length

The average pregnancy duration in pigs, lasting approximately 114 days (or 3 months, 3 weeks, and 3 days).

Duroc

A swine breed developed in the United States featuring a solid red body and drooping ears, highly valued for growth rate and terminal traits.

Hampshire

An English swine breed characterized by erect ears and a black body with a white belt around the shoulders, known for high muscle content and lean yield.

Landrace

A white swine breed imported from Denmark with large drooping ears and an elongated body, noted for exceptional maternal instincts.

Yorkshire

Known as the mother breed, this solid white English swine breed has erect ears and leads United States swine breed registrations due to superior maternal performance.

Berkshire

The oldest recognized swine breed, originating in England, featuring erect ears, a black body with six white points, and high marbling capacity.

Swine ear notching system

An identification method where notches in the pig right ear indicate the litter number and notches in the left ear indicate the individual pig number.

PSE (Pale, Soft, Exudative) meat

A swine meat quality defect caused by acute pre-slaughter stress, resulting in pale color, soft texture, and poor water retention capacity.

DFD (Dark, Firm, Dry) meat

A carcass quality defect resulting from long-term stress or glycogen depletion prior to harvest, yielding dark, firm, and dry muscle tissue.

US Swine Grade Formula

The mathematical relationship used to calculate pork carcass grade: $\text{US Grade} = (4 \times \text{LRBF}) - \text{MS}$, where LRBF is last rib backfat in inches and MS is muscle score.

Swine dressing percentage

The proportion of live weight retained as hot carcass weight, calculated as $\text{Dressing Percentage} = \frac{\text{Hot Carcass Weight}}{\text{Live Weight}} \times 100$.