TEMPORARY ENVIRONMENTAL EFFECT: An environmental effect that influences a single performance record of an individual but does not permanently affect the individual's performance potential for a repeated trait.

TERMINAL SIRE: A paternal-breed sire used in a terminal sire crossbreeding system.

TEST CROSS: Also test mating. A mating designed to reveal the genotype of an individual for a small number of loci.

TOPS: A continuous, untwisted strand of combed alpaca fibers from which the shorter fibers have been removed by combing.

TRAIT: Any observable or measurable characteristic of an individual.

TRAIT OF THE DAM: A trait in which each progeny record is attributed to the dam, not the offspring. 

 TRAIT OF THE OFFSPRING: A trait in which each record is attributed to an offspring, not to its dam.

TUI: An eighteen-month-old alpaca.

VALUE: Any measure applied to an individual as opposed to a population. Examples are phenotypic value, genotypic value, breeding value, and environmental effect.

VARIABILITY: The differences between animals within a given population.

VARIATION: In most animal breeding applications, the differences among individuals within a population.

VICUNA: Native South American camelid, thought to be the ancestor of the domesticated alpaca. Vicunas, which exhibit the finest natural fiber in the world, can cross-breed with alpacas.

YARA: Quechua word for the color black.

WOOLEN: Yarn made from fibers that are one to three inches in length and that have been carded only. Fabrics of woolen yarn are characterized as being fuzzy, thick, and bulky.

WORSTED: Yam spun from fibers three inches in length or longer that have been carded, combed, and drawn. Combing machines straighten alpaca slivers, making the individual fibers lie parallel.