DAM: A female parent.
DIRECT RESPONSE TO SELECTION: Genetic change in a trait resulting from selection for that trait.
DNA: the molecule that forms the genetic code.
DYSTOCIA: Difficulty in giving birth or being born.
ECONOMIC SELECTION INDEX: An index or combination of weighting factors and genetic information - either phenotypic data or genetic predictions - on more than one trait. Economic selection indexes are used in multiple-trait selection to predict aggregate breeding value.
EFFECTIVE POPULATION SIZE: The size of a population as reflected by its rate of inbreeding.
EMBRYO: An organism in the early stages of development in the shell (bird) or uterus (mammal).
EMBRYO TRANSFER: A reproductive technology in which embryos from donor females are collected and transferred in fresh or frozen form to recipient females.
ENVIRONMENTAL EFFECT: The effect that external (nongenetic) factors have on animal performance.
ENVIRONMENTAL TREND: Change in the mean performance of a population over time caused by changes in environment.
ESTANCIA: A medium-sized farming property in single ownership, comparable to a western United States ranch.
ESTIMATED BREEDING VALUE: A prediction of a breeding value. See breeding value.
FAMILY: A group of related individuals within a population, most often applied to half-sib and full-sib families, but which can be applied to less related groups including all descendants of a particular ancestor.
FERTILITY: The ability of a female to conceive or of a male to impregnate.
FINENESS: A measure, in microns, of the diameter of individual fibers. Most often expressed as an average for a representative sample of fiber.
FITNESS: (1) The ability of an individual and its corresponding phenotype and genotype to contribute offspring to the next generation. (2) The number of offspring an individual produces, not just its ability to be selected.
FITNESS TRAIT: A trait selected for by natural selection. Fitness traits relate to an animal's ability to survive and reproduce.
FLEECE WEIGHT: The weight of an entire fleece measured at the same time each season.