Beef Cattle Terminology continued

Ovulation--Release of the female germ cell (egg) by the ovary. Cows usually ovulate several hours (up to 15 hours) after the end of estrus or standing heat.

Parturition--The act of giving birth; calving.

Pedigree--A tabulation of names of ancestors, usually only those of the three to five closest generations.

Performance Data--The record of the individual animal for reproduction, production, and possibly carcass merit. Traits included would be birth, weaning and yearling weights, calving ease, calving interval, milk production, etc.

Performance Pedigree--A pedigree that includes performance records of ancestors, half and full sibs, and progeny in addition to the usual pedigree information. Also, the performance information is systematically combined to list estimated breeding values on the pedigrees by some breed associations.

Performance Test -- In a performance test, phenotypic values for economically important traits are recorded on animals that have been managed as uniformly as possible, such that performance records will reflect transmissible genetic merit as accurately as possible.

Performance Testing--The systematic collection of comparative production information for use in decision making to improve efficiency and profitability of beef production. Differences in performance among cattle must be utilized in decision making for performance testing to be beneficial. The most useful performance records for management, selection, and promotion decisions will vary among purebred breeders and for purebred breeders compared with commercial cattle producers.

Phenotype--The visible or measurable expression of a character; for example, weaning weight, postweaning gain, reproduction, etc. Phenotype is influenced by genotype and environment.

Phenotypic Correlations--Correlations between two traits caused by both genetic and environmental factors influencing both traits.

Phenotypic Selection -- Phenotypic selection occurs when individuals are selected to become the next generation of parents based upon their phenotypic merit for a particular trait or traits. Because "like tends to beget like", selection of phenotypically superior parents should increase progeny merit for the selected trait.

Planned Matings -- Planned matings occur when the cattle breeder chooses to mate a particular male with a particular female in an attempt to achieve a desired result. Crossbreeding is a planned mating, for example, when practiced in an attempt to benefit from heterosis. See also random mating.

Polled--Naturally hornless cattle. Having no horns or scurs.Planned matings. Planned matings occur when the cattle breeder chooses to mate a particular male with a particular female in an attempt to achieve a desired result.

Pounds of retail cuts per day of age--A measure of cutability and growth combined, it is calculated as follows: cutability times carcass weight divided by age in days. Also, it is reported as lean weight per day of age (LWDA) by some associations.

Possible change--The variation (either plus or minus) that is possible for each expected progeny difference (EPD). This measurement of error in prediction or estimation of EPD decreases as the number of offspring per sire increases.

Prepotent-The ability of a parent to transmit its characteristics on its offspring so that they resemble that parent, or each other, more than usual. Homozygous dominant individuals are prepotent. Also, inbred cattle tend to be more prepotent than outbred cattle.

Production Trait -- Production traits are those that directly influence cost or revenue from beef cattle production; growth rate, feed intake and carcass merit, for example.

Progeny records--The average, comparative performance of the progeny of sires and dams.

Progeny testing--Evaluating the genotype of an individual by a study of its progeny records.

Puberty--The age at which the reproductive organs become functionally operative and secondary sex characteristics begin to develop.

Purebred--An animal of known ancestry within a recognized breed that is eligible for registry in the official herdbook of that breed.

Qualitative traits-Those traits in which there is a sharp distinction between phenotypes, such as black and white or polled and horned. Usually, only one or few pairs of genes are involved in the expression of qualitative traits.

Quantitative trait--Those traits in which there is no sharp distinction between phenotypes, with a gradual variation from one phenotype to another, such as weaning weight. Usually, many gene pairs are involved, as well as environmental influences.

Random mating -- In random mating, the alternative to planned mating, males and females are mated without regard to their genetic relationship or to their phenotypic similarity. A system of mating where every female (cow and/or heifer) has an equal or random chance of being assigned to any bull used for breeding in a particular breeding season. Random mating may be required for accurate progeny tests.

Rate of genetic improvement-Rate of improvement per unit of time (year). The rate of improvement is dependent on: (1) heritability of traits considered; (2) selection differentials; (3) genetic correlations among traits considered; (4) generation interval in the herd; and (5) the number of traits for which selections are made.

Reach--See Selection differential.

Recessive gene--Recessive genes affect the phenotype only when present in a homozygous condition. Recessive genes must be received from both parents before the phenotype caused by the recessive genes can be observed.