Beef Cattle Terminology continued

Carcass quality grade--An estimate of palatability based primarily on marbling and maturity and generally to a lesser extent on color, texture, and firmness of lean. Days on feed and fat thickness (of 0.25 inches or more) are comparable to quality grade in estimating eating quality.

Carcass quantity--Amount of salable meat (muscle) the carcass will yield. Cutability is an estimate of this. (See its definition.)

Carrier--A heterozygous individual having one recessive gene and one dominant gene for a given pair of genes (alleles). For example, an animal with one gene for polledness and one gene for horns will be polled but can produce horned offspring when mated to another animal carrying the gene for horns

Central test--A location where animals are assembled from several herds to evaluate differences in certain performance traits under uniform management conditions.

Chromosome--Chromosomes are long DNA molecules on which genes (the basic genetic codes) are located. Domestic cattle have 30 pairs of chromosomes.

Closed herd--A herd in which no outside breeding stock (cattle) are introduced.

Collateral relatives--Relatives of an individual that are not its ancestors or descendants. Brothers and sisters are an example of collateral relatives.

Conception--The fertilization of the ovum (egg). The act of conceiving or becoming pregnant.

Congenital--Acquired during prenatal life. Condition exists at or dates from birth. Often used in the context of congenital (birth) defects.

Contemporary group--A group of cattle that are of the same breed and sex and have been raised in the same management group (same location on the same feed and pasture). Contemporary groups should include as many cattle as can be accurately compared.

Correlated Selection Response -- Correlated response to selection is the change that occurs in one or more traits as some other trait is subjected to directional selection. It occurs when some of the same genes affect the direct and correlated traits simultaneously, a phenomenon known as pleiotropy. Correlated responses may be
beneficial, neutral or harmful, depending on the biology and economic impact of the traits in question. See also genetic correlation.

Correlation--A measure of how two traits vary together. A correlation of + 1.00 means that as one trait increases the other also increases a perfect positive relationship. A correlation of -1.00 means that as one trait increases the other decreases--a perfect negative, or inverse, relationship. A correlation of 0.00 means that as one trait increases, the other may increase or decrease--no consistent relationship. Correlation coefficients may vary between +1.00 and -1.00.

Crossbreeding--The mating of animals of different breeds (or species). Crossbreeding usually results in heterosis (hybrid vigor).

Culling--The process of eliminating less productive or less desirable cattle from a herd.

Cutability--An estimate of the percentage of salable meat (muscle) from a carcass versus percentage of waste fat. Percentage of retail yield of carcass weight can be estimated by a USDA prediction evaluation that includes hot carcass weight, ribeye area, fat thickness, and estimated percent of kidney, pelvic, and heart fat.

Dam--The female parent.

Decision Support Program -- A decision-support program is a set of rules, usually coded into a computer program, which allows a user to evaluate biological and economic impacts of breeding and management strategies on a production system.

Deviation -- difference between an individual record and the average for that trait for that contemporary group. These differences sum to zero when the correct average is used. A ratio deviation is the ratio less the average ratio or 100.

DNA Marker -- A DNA marker is a specific sequence on nucleotides within a particular gene that can be detected through laboratory analysis and can be used to determine which alleles are present at that locus in an individual. See also marker-assisted selection.

Dominance--Dominant genes affect the phenotype when present in either homozygous or heterozygous condition. A dominant gene need only be obtained from one parent to achieve expression.

Dystocia (calving difficulty)--Abnormal or difficult labor causing difficulty in delivering the fetus and/or placenta.

Economic value--The net return within a herd for making a pound or percentage change in the trait in question.

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. In the context of beef cattle breeding, the environment includes the net effect of all nongenetic factors that influence an animal's phenotype for a particular trait, up until the time that the trait is observed or expressed. Factors that contribute to the environment include but are not limited to physical geography, climate, quantity and quality of the diet, management practices and health maintenance programs.

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