RANDOM MATING: The joining of animals on an entirely random basis without regard to pedigree or phenotype.
RECOMBINATION: The formation of a new combination of genes on a chromosome as a result of crossing over.
REFERENCE SIRE: These sires leave offspring in several, possibly all, of the cooperating flocks. The offspring of the reference sires can then be compared with the offspring of any other sires used in the same flock. Thus, the best males in the whole of the group breeding scheme: 1) can be identified, with the help of appropriate statistical programs; 2) can become available to the scheme as a whole; and 3) can be used to breed the next generation of males.
REPEATABILITY: (1) A measure of the strength of the relationship between repeated records (repeated phenotypic values) for a trait in a population. (2) A measure of the strength of the relationship between single performance records (phenotypic values) and producing abilities for a trait in a population.
REPEATED TRAIT: A trait for which individuals commonly have more than one performance record.
REPLACEMENT RATE: The rate at which newly selected individuals replace existing parents in a population.
REPLACEMENT SELECTION: The process that determines which individuals will become parents for the first time.
ROAN: Animal coat color determined by a fairly uniform mix of colored fibers. For example, the coat of a silver alpaca is actually made up of intermittent black and white fibers.
SEEDSTOCK: Breeding stock; animals whose role is to be a parent or, in other words, to contribute genes to the next generation.
SEGREGATION: The separation of paired genes during germ cell formation.
SELECTION: The process that determines which individuals become parents, how many offspring they may produce, and how long they remain in the breeding population.
SELECTION ACCURACY: Also accuracy of breeding value prediction. The measure of the strength of the relationship between true breeding values and their predictions for a trait under selection.
SELECTION CRITERIA: Phenotypic values or other pieces of information that form the basis for selection decisions.
SELECTION INTENSITY: (1) A measure of how particular breeders are in deciding which individuals are selected. (2) The difference between the mean selection criterion of those individuals selected to be parents and the average selection criterion of all potential parents, expressed in standard deviation units.
SELECTION RISK: The risk that the true breeding values of replacements will be significantly poorer than expected.
SELECTION SYSTEM: The method a breeder chooses to select breeding stock.
SELECTION TARGET: A level of breeding value considered optimal in an absolute or practical sense.
SIMPLY INHERITED TRAIT: A trait affected by only a few genes.
SINGLE-TRAIT SELECTION: Selection for one trait.
SIRE: A male parent.
SIRE SUMMARY: A list of genetic predictions, accuracy values, and other useful information about the sires in a breed.
SKEWBALD: Pinto; in the New Zealand color study, an alpaca with white and brown patches.
SLIVERS: A continuous, untwisted strand or rope of parallel alpaca fibers approximately uniform in cross-section, produced by the carding and drawing process. Carded slivers are blended prior to combing in the manufacture of worsted yarn.
SPOTTING GENES: A gene which may control spots or color pattern on an alpaca. The existence of a spotting gene has not been scientifically verified.
STANDARD DEVIATION: A mathematical measure of variation that can be thought of as an average deviation from the mean. The square root of the variance.
STAPLE LENGTH: The length of a lock or length of shorn alpaca fleece.
STAPLE: An organized independent group or cluster of individual fibers. A large number of staples constitute a fleece.
SURI: A breed of alpaca characterized by lustrous locks of fleece that lay close to the body, twisting vertically toward the ground.
SYNDACTYLISM: Having two or more toes fused together.