Effective progeny number (EPN)--An indication of the amount of information available for estimation of expected progeny differences in sire evaluation. It is a function of number of progeny but is adjusted for their distribution among herds and contemporary groups and for the number of contemporaries by other sires. EPN is less than the actual number because the distribution of progeny is never ideal.

 Environment--All external (nongenetic) conditions that influence the reproduction, production, and carcass merit of cattle.

Embryo--A fertilized ovum (egg) in the earlier stages of prenatal development usually prior to development of body parts.

Embryo transfer--Removing fertilized ova (embryos) from one cow (donor dam) and placing these embryos into other cows (host cows), usually accompanied by hormone-induced superovulation of the donor dam. More calves can be obtained from cows of superior breeding value by this technique. Only proven producers should become donor dams.

Estimate--The process of calculating a particular value from data (verb). The value itself obtained from data (noun). The idea is that the true value is being obtained from the calculated value within limits of sampling variation.

Estimated breeding value (EBV)--An estimate of an individual's true breeding value for a trait based on the performance of the individual and close relatives for the trait. EBV is a systematic way of combining available performance information on the individual, brothers, and sisters of the individual, and the progeny of the individual.

Estrus (heat)--The recurrent, restricted period of sexual receptivity in cows and heifers. Nonpregnant cows and heifers usually come into heat 18 to 21 days following their previous estrus.

Expected progeny difference (EPD)--The difference in performance to be expected from future progeny of a sire, compared with that expected from future progeny of the average bull in the same test. EPD is an estimate based on progeny testing and is equal to one-half the estimate of breeding value obtainable from the progeny test records.

F1--Offspring resulting from the mating of a purebred (straightbred) bull to purebred (straightbred) females of another breed.

Feed conversion (feed efficiency)--Units of feed consumed per unit of weight gained. Also the production (meat, milk) per unit of feed consumed.

Frame score--A score based on subjective evaluation of height or actual measurement of hip height. This score is related to slaughter weights at which cattle will grade choice or have comparable amounts of fat cover over the loin eye at the 12th to 13th rib.