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see bottom of page for Glossary of technical terms for commercial cattle industry & research

Allele: Alternate form of a gene. It can also be thought of as variations in a DNA sequence. For instance, if an animal has the genotype for a specific gene of Bb, then both B and b are alleles. Because genes occur in pairs in body cells, one gene of a pair may have one effect and another gene of that same pair (allele) may have a different effect on the same trait.

Alliance: A cooperative business arrangement in which a cattle producer, sometimes in cooperation with other producers, arranges for the retained ownership and/or contract sale of his/her animals before they actually are produced. The agreement typically defines the breeding system, selection methods, management conditions, and product specifications for the cattle. See also syndicate.

Animal Unit (AU). Animal units are the basis for calculating stocking rates or pasture needed for livestock. The standard single (1) AU = one 1000 lb cow (or cow-calf pair that weighs 1000 together). To calculate the number of animal units you have, multiply the number of head by the animal unit equivalent of your cows. By the example above: 100 cows x (1400 lb [weight of your cows] / 1000 [weight of one animal unit]) = 100 head x 1.4 AUE = 140 AUs
An "animal unit equivalent" is the adjustment that is calculated from the standard animal unit based on the average weight of your livestock. AUEs can be used for any weight of grazing animal being used on the pasture, from sheep to bulls to horses to deer. The calculation simply involves dividing the average weight of your animals by the weight of the standard animal unit.

AUM. One Animal Unit for One month of grazing. Refers to stocking rate, figured by how many acres support 1 animal unit per month.

  • FORMULA 1) Classic stocking rate is calculated upon half of half of the total dry matter produced each year. This was based on the idea that you wanted to take half and leave half, therefore the initial 50% reduction. Then range scientists assume another 50% of available forage will be wasted through trampling, weather or fouling by urine or dung. The underlying math for calculating stocking rate is really fairly simple (but of course has many variables we can't always account for). Regardless, it is basically the amount of dry matter grown each year on the property in question, matched up with the expected consumption of the livestock on the place. There are some pretty accurate estimates of forage consumption for various livestock classes available on the internet, but a really simple rule of thumb is that a 1000 lb cow eats about 30 pounds per day of dry matter throughout the year.
  • FORMULA 2) One AU (1000 lbs) is estimated to consume between 600 and 900 lb of forage in one month. A default average used by all stockmen to calculate their stocking rate for their land is that one animal unit will consume 800 pounds of forage in one month. This is what makes an Animal Unit Month (AUM). Stocking Rate: To calculate your stocking rate, let's assume your pasture is safely providing 800 pounds of grazable forage per acre (with plenty to spare, that is, not overgrazing it). The stocking rate for your location is determined by the amount of forage your pasture provides in terms of pounds per acre per month. If you have hayed your pasture acreage you will have an idea about how many pounds of forage it produces per acre. We know that one AUM consumes approx 800 pounds of forage a month, so, that will give you a stocking rate of 1.0 AUM/acre. If your miniature cattle average 500 lbs each, your stocking rate would be 2 head / acre during normal growing season.

Artificial insemination (AI): The technique of placing semen from the male into the reproductive tract of the female by means other than natural service.

Aught: "0" "oh" or zero. Aught is a vintage Middle English term that refers to zero, or used with a succession of zeroes when labeling smaller than normal sizes; still used in some areas, in agriculture & in tools. Zero (0) or 1 may refer to an average or median range. Going upwards in number indicates an increase in size. Going below 0 is going smaller in size. Aught is used with grains (00-6 is "double aught six" in a shotgun shell), in small horseshoes, and in screw thread sizes, includes 000 (“triple aught”), 00 (“double aught”), 0 (“aught”), #1 and #2, sizes made to National Aerospace Standards). Size 0000 is called 4-aught, 00000 is called 5-aught, 000000 is called 6-aught., and in Frame Score chart sizes in miniature and small frame cattle compared to standard size breeds of cattle.

Autosomal: meaning, not connected to the gender of an animal. X and Y are the two best known pair of chromosomes; they determine the biological sex of an animal. The rest of the chromosome pairs are called autosomes or autosomal chromosomes. Most genetic traits that are passed down from parent to offspring are therefore autosomal dominant or autosomal recessive genes--traits that occur the same regardless of the animal's sex. An example of a sex-linked trait would be a calico female cat, or the differences in polled, scurs and horn inheritance in bos taurus taurus breeds of cattle.

Average daily gain (ADG): Measurement of the average daily body weight change over a specified period of time of an animal on a feed test.

go to top Backcross: The mating of a two-breed crossbred individual back to one of its parental breeds. Example: A Hereford X Angus crossbred cow bred back to an Angus bull.

Backgrounder/ Grower/ Stocker: Guy who buys weaned calves to feed and grow. This is done in a variety of ways depending mostly on location, some are grazed and some are fed in lots.

Baldie: A crossbred bovine of any color with a white face or head, most are black, and called a "Black Baldy or Baldie" (BB). Also known as a Black whiteface (BWF) or when red, a Red whiteface (RWF). A Baldie will most likely by produced by a Hereford, sometimes a Simmental or other European breed. When a whiteface calf is about 1/4 Hereford, it is often a brockle-face. See: Black whiteface.

Beef: meat from cattle (bovine species) other than calves. Meat from calves is called veal.

Beefmaster: is a composite breed of beef cattle that was established in the early 1930s by Tom Lasater, after his father Ed C. Lasater created the composite from crossing Hereford and Shorthorn cows with Brahman bulls. The exact mixture of the foundation cattle is unknown, but is thought to be about 25% Hereford, 25% Shorthorn and 50% Brahman.

Beef carcass data service: A program whereby producers, for a fee, can receive carcass evaluation data on their cattle by using a special carcass data ear tag for their slaughter animals. See county extension director, breed representative, Beef Cattle Improvement Association representative, or area office of USDA meat grading service for information.

Beef Checkoff: “The American producer has spent millions of dollars to advertise the product of four companies that get up everyday trying to screw them.” Every time cattle are sold a $1 per head fee is taken out of the check and paid into the Beef Checkoff program ( The National Cattlemans Beef Assocation (NCBA) gets the majority of this checkoff money. NCBA represents the 4 big packers. The Beef Checkoff fee is not voluntary, it is a taxation-without-representation deduction taken from all cattle sales run through official marketing systems (auctions, brand inspections, etc.). R-Calf's budget is over $40 million a year to advertise beef which no longer has anything to do with the price cattlemen are paid for selling their cattle.

Beef Improvement Federation (BIF): A federation of organizations, businesses, and individuals interested or involved in performance evaluation of beef cattle. It seeks to build confidence of the beef industry in the principles and potentials of performance testing. The purposes of BIF are to achieve utilization of the most efficient and effective performance evaluation methods, uniformity of procedures, development of programs, cooperation among interested entities, and education of its members.


  • American Akaushi Association 732 Jeff Davis Road Harwood, TX 78632
  • American Angus Association 3201 Frederick Blvd. St. Joseph, M O 64506
  • American Blonde d’Aquitaine Association 7407 VZ County Road 1507 Grand Saline, TX 75140
  • American Brahman Breeders International 3003 South Loop West, Suite 520 Houston, TX 77054
  • American British White Park Association PO Box 957 Harrison, AR 72602
  • American Chianina Association P.O. Box 890 Platte City, MO 64079
  • American Gelbvieh Association 10900 Dover Street Westminister, CO 80021
  • American Hereford Association 1501 Wyandotte Kansas City, MO 64108
  • American-International Charolais Association 11700 NW Plaza Circle Kansas City, MO 64153
  • American Maine: Anjou Association P.O. Box 1100 Platte City, MO 64079: 1100
  • American Salers Association 19590 East Main #202 Parker, CO 80138
  • American Shorthorn Association 8288 Hascall St. Omaha, NE 68124
  • American Simmental Association 1 Simmental Way Bozeman, MT 59715
  • American Tarentaise Association 9150 N 216 Street Elkhorn, NE 68022
  • American Wagyu Association PO Box 547 Pullman, WA 99163
  • Beefmaster Breeders United 6800 Park Ten Blvd., Suite 290 West San Antonio, TX 78123
  • Braunvieh Association of America 3815 S Touzalin Ave., Suite 103 Lincoln, NE 68507
  • Canadian Angus Association 142, 6715: 8th Street NE Calgary, AB T2E 7H7 Canada
  • Canadian Beef Breeds Council
  • Canadian Charolais Association 2320: 41 st Ave., NE Calgary, AB T2E 6W8 Canada
  • Canadian Gelbvieh Association 110, 2116 27th Ave., NE Calgary, AB T2E 7A6 Canada
  • Canadian Hays Converter 201, 1600 15 Ave., SW Calgary, AB T3C 0Y2 Canada
  • Canadian Hereford Association 5160 Skyline Way, NE Calgary, Alberta T2E 6V1 Canada
  • Canadian Limousin Association 13, 4101 19th St., NE Calgary, AB T2E 7C4
  • Canadian Simmental Association 13, 4101 19th St., NE Calgary, Alberta T2E 7C4 Canada
  • International Brangus Breeders Association PO Box 696020 San Antonio, TX 78269
  • National Association of Animal Breeders (NAAB) and Certified Semen Services (CSS)
  • National Cattlemen's Beef Association
  • North American Limousin Foundation 7383 S. Alton Way, Suite 100 Centennial, CO 80112
  • North American South Devon 19590 East Main Street #202 Parker, CO 80138
  • Red Angus Association of America 4201 North I35 Denton, TX 76207
  • Santa Gertrudis Breeders International P.O. Box 1257 Kingsville, TX 78364
  • (and many more state, provincial and other associated member organizations)

Biological type: A group of cattle breeds having similar geographic origin and past selection history and with similar genetic potential for traits of economic importance. British general purpose beef cattle breeds, for example, have genetic potential for moderate growth, muscling, and milk yield; whereas continental European dual-purpose breeds have genetic potential for high milk yield and rapid growth.

Biosecurity: A biosecurity program is a set of management practices used to minimize the introduction to disease, spread of disease within the herd, and transport of disease off the farm. Using biosecure best management practices reduces clinical disease, improves production, and increases profitability. It is cheaper and easier to prevent disease than treat it.

Birth weight (BW or bwt): The weight of a calf taken within 24 hours after birth. The calf's birth weight is heaviest right after birth and nursing, but the calf can shrink 8 to 10 pounds by the time it is 18 hours old. A normal healthy calf may shrink up to 10% of its body weight during the first 24 hours dependent on temperature, suckling response, and time of weighing. Heavy birth weights tend to be correlated with calving problems (see calving difficulty or dystocia). Newborn calves often weigh about 7 percent of their mother's weight. For example, a 1000 pound heifer may give birth to a 70 pound calf. Higher than normal temperatures may result in lower birth weights. Cold temperatures during the last trimester can result in higher birth weights, up to 1 pound for every 1 degree F below normal temperatures. A cow's circulation increases as an aide to keep warm - which translates to more blood flow to the calf too. Birth weights can increase up to 1 pound for every day past a cow goes past her due date, too. Caloric restriction of a heifer during gestation can result in a lower birth weight, but only if calories are restricted to less than 70 percent of her daily needs.

Brockle faced calf  - RM PhotographyBlack whiteface (BWF): A familiar crossbreed, also called a Black Baldie (BB). Phenotype definition is a black bovine with a white head or face, with or without additional white markings on underbelly, tail switch, legs etc. The genotypic definition usually refers to an F1 (first filial, or first crossbreeding) of a Hereford X black Angus. A Red whiteface (RWF) would be Hereford X Red Angus. A Black brockleface (BBF) or Red brockleface (RBF), and / or goggle eyed, are markings expected in the following F2 (and so on) generations, (F1 X F1 = F2 breedings) as the pure white head breaks down into further spotting or markings on head or face. See brockling in coat color genetics.

Bob: (1) [verb] To cut off some length. A method of marking cattle by trimming their tail hair. The cowman might "bob" the tails of the cattle he intends to keep while he is working them. This mark is made by cutting straight across the end tassel of tail hair. The mark is very distinctive and able to be seen from a long distance. (2) [adjective] A bob or bobbed tail is a shorter than usual tail.

Body capacity: A subjective assessment of the feed intake capacity of an individual or breed, typically assessed by visually evaluating body length, body depth, and spring of ribs.

Body Condition Score (BCS): A score on a scale of 1 to 9, reflecting the amount of fat reserves in a cow's body, where 1 = very thin and 9 = extremely fat. See Body Condition Score charts.

old illustration showing points where you determine BCS

Bos indicus: A subspecies of cattle of south Asian origin. Often known as Zebu, they have prominent humps forward of the shoulder. The Brahman breed is one example in the United States.

Bos taurus: A subspecies of cattle of western Asian origin but often referred to as "European". Most breeds commonly found in the United States and Canada, and their European ancestors, belong to this group. Bos indicus x Bos taurus crosses are viable and fully fertile and exhibit large amounts of heterosis.

Brand: (1) [noun] Ownership mark. (2) [verb] to apply a brand; a hot brand or a cold (freeze) brand. Brand states register brands to owners, usually renewed each decade. To transport animals in or out of a brand state, a shipper must have a current brand inspection, which serves as proof of ownership or bill of sale; whether the animal is actually branded or not.

Branding: After all the calves are on the ground (born), ranches invite their neighbors to load up their stock horses, and come help round them all up and vaccinate and brand them. Fellowship and a big meal afterwards, turns a branding into the social event of the year.

Branding Iron: the tool used to apply a brand. Called "iron" for short. (I have too many irons in the fire). A running iron is a round ring or flat iron used to draw a brand rather than stamp it on. In the old west running irons were sometimes used by rustlers to claim maverick cattle that didn't belong to them. In some places it is still illegal to carry a running iron; in others, it is a common practice to apply a legal brand with one.

Breed: Animals with a common origin and selection history. Animals within a breed have physical characteristics that distinguish them from other breeds or groups of animals within that same species. For (an excellent Cliffs Notes style) history of type, breeds & purity of British and Continental breeds in America, see What is a Breed. See also: Homestead Cattle Breeds of North America.

Breed association: An organization that maintains pedigree and performance information and arranges for timely genetic evaluation of animals within that breed. Breed associations also establish regulations for registration of animals, promote the breed, and advance the interests of the breeder members. Read more about the purpose of registries (no.10) here: 10 Things to Know When Choosing a Breed

Breed characteristics: Breed specific characteristics, also known as breed traits, are inherited traits that purebred animals pass from generation to generation. Thus, all specimens of the same breed carry several genetic characteristics of the original foundation animal(s). In order to maintain the breed, a breeder would select those animals with the most desirable traits, to achieve further maintenance and developing of such traits. At the same time, avoiding animals carrying characteristics, not typical and/or undesirable for the breed, known as faults or genetic defects. The population within the same breed consists of a sufficient number of animals to maintain the breed within the specified parameters without the necessity of forced inbreeding. The breed includes several bloodlines that can be interbred to sustain the breed in whole without weakening the gene pool. Domestic animal breeds commonly differ from country to country, and from nation to nation.

Breeding objective: The goal of a breeder's selection program, for example to produce high quality, lean meat at lowest cost. It may also include a listing of economically related traits to be used as selection criteria to achieve the overall goal. Objectives may vary among breeders due to their genetic and physical resources and their markets.

Breeding Soundness Examination /evaluation (BSE): Inspection of a bull, including evaluation of physical conformation and soundness through genital palpation, scrotal circumference assessment, and testing of semen for motility and morphological abnormalities. Avoid breeding disasters by checking herd sires before each breeding season. Don’t guess on your bulls’ performance, have him checked. BSE’s are very cheap insurance against either a very scattered or no calf crop at all.

Breeding up: verb, Upgrading (see also: Purebred). The process of developing a high percentage breed animal, using another breed to start out with. Usually done in cases where importation is not feasible.

Breeding value: Transmissible genetic merit of an individual, or the value of that individual as a parent. In the United States and Canada, genetic predictions are expressed as progeny differences rather than as breeding values. Because any parent contributes only half the genes in any one offspring, the progeny difference of an individual is half its breeding value.

British breeds: Breeds of cattle originating in Great Britain such as Dexter, Kerry, Galloway, Welsh Black, Angus, Hereford, Scottish Highland, Shorthorn, etc.

Brockitt Faced: “Old Scottish publications document White Face Galloway as Brockitt Faced. Another autosomal incompletely dominant gene with a defined infusion point. Last I read some years back another likely Cs6 mutation.” Alan S. Bias

Brockle-Face: See Black whiteface (Baldie).

Browsing: is a [1.] type of herbivory in which an herbivore (or, more narrowly defined, a folivore) feeds on leaves, soft shoots, or fruits of high-growing, generally woody, plants such as shrubs. Mature leaves often contain a high proportion of hard-to-digest cellulose, less energy than other types of foods, and more often toxic compounds. For this reason, folivorous animals tend to have long digestive tracts and slow metabolisms. This is contrasted with grazing, usually associated with animals feeding on grass or other low pasture vegetation. [2.] Grazers are animals that eat mainly grass, and browsers are animals that eat both, or, mainly non-grasses, which include both woody and herbaceous dicots. In either case, an example of this dichotomy are goats (which are browsers) and sheep (which are grazers); these two closely related ruminants utilize dissimilar food sources.

BSE: see Breeding Soundness Exam. Also see Bull Testing.

Bull: an intact, un-castrated male bovine. Well bred bulls are marketed to sire desirable calves in a cow herd. A bull calf is a male calf.

BW or BWT. Birthweight.

go to top Caesarean section: A process in which the calf is surgically removed from the cow during parturition by making a large incision in the right side of the cow just above the flank.

Calf: baby or young bovine. This term is used from the time of birth up until about 6 to 10 months of age when the animal is weaned. Usually cattlemen plan for their herds to calve (have their young) in the early spring. In warmer climate some ranches allow calving any time, or year round. Calves are ear-tagged at birth for identification. A typical (standard breed) calf weighs between 55 and 100 pounds. Miniature calf BWTs range from 18 to 45 lbs. In official research and record-keeping, the definition for calf (age) is (calf: =270 days of age, yearling: 271–365 days of age, and long yearling: >365 days of age)

Calving difficulty (Dystocia): Abnormal or difficult labor, causing difficulty in delivering the fetus and/or placenta. Difficult births lead to increased calf and cow mortality and to more difficult rebreeding of the cow. Factors that can influence calving difficulty include the cow's age, the width of the cow's pelvis, the size of the cow compared with the size of the bull, the width of calf's head, shoulders or hips, and presentation (breech births, legs or head back, birth defects, etc.) It's about more than just EPDs and numbers though. I had some friends in MT who owned a well-known AI sire (Polled Pack Leader). His calving BWT EPD was quite high, and unless you knew the rest of the story, you wouldn't be inclined to buy his semen. They sold a lot of his semen however, and that's because ranchers knew by word of mouth that PPL had a genetic knack for siring calves as big, but only as big as a cow could safely calve them out. He was bred to 1000's of cows and LOTS of the calves were over 100# BWT. None we ever heard of had calving difficulty due to size or shape of the calf. Just goes to show you.

Calving ease: A description of how much (if any) difficulty is encountered at calving for the cow. An easy calving is one that does not require assistance and does not impose undue strain on the cow or calf. See calving ease chart.

calf in utero
normal position of calf in utero (source: workbox)

Calving ease (CE) score: A numerical score quantifying calving ease, ranging from 1 for an easy, unassisted calving through 5 for an abnormal presentation. Go here and scroll down to see the CE score chart.

Calving season: The season(s) of the year when the calves are born. Limiting calving seasons is the first step to performance testing the whole herd, accurate records, and consolidated management practices.

Carcass: the body of a slaughtered animal after removal of the offal.

Carcass evaluation: Techniques for measuring components of quality and quantity in carcasses and using the information for genetic predict ion of carcass merit.

Carcass merit: Desirability of a carcass relative to quantity of components (muscle, fat, and bone), USDA quality grade, and potential eating quality.

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.

Carrier: An animal that is heterozygous for a trait. Animal having one dominant and one recessive allele at a given locus. 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 also carrying the gene for horns.

Castrate: to remove the testicles, thus rendering a bull infertile.

Cattle Guard: An obstacle to cattle in a roadway made from horizontal (usually metal) bars (hopefully round pipe bar) inserted in the roadway over a depression in the ground and parallel to the fence line. It is used to replace a gate on a roadway. The gaps between the bars is a visual deterrent to cattle and they will usually not attempt to cross it. Fake cattle guards are sometimes painted on freeway entrances etc., because the appearance of crossing bars over a hole will also deter cattle.

Certified Semen Services (CSS) is a wholly owned subsidiary of NAAB. Formed in 1976, CSS is an objective auditing service developed by responsible AI industry leaders through NAAB. CSS provides industry self-regulation in the areas of semen and sire health and identification.
Chromosome: Chromosomes are paired strands of DNA, with accompanying structural proteins, on which genes are located. Domestic cattle have 30 pairs of chromosomes, one chromosome of each pair having been inherited form each parent. One random chromosome of each pair is transmitted to each egg or sperm cell produced by a parent.

Circle: Refers to riding a certain (usually large) area of a cattle ranch, to inspect (ride) the fence or check on or round up cattle. A stock horse used on big ranches is a horse that is good for riding big circles.

CJLD: congenital joint laxity and dwarfism.

Closed herd: A herd in which no outside breeding stock (cattle) are introduced. See also

Cod: scrotal area of a steer that remains after castration.

colostrum pinColostrum: Colostrum is the first “milk” produced by a cow after parturition. Lack of colostrum is a calf killer for many reasons, for example; calf scours causes more financial loss to cow-calf producers than any other disease-related problem on the farm, and recent research indicates that many scour cases can be directly related to lack of colostrum intake by the newborn calf. A calf that is well mothered and consumes 1 to 2 quarts of colostrum in the first few hours after birth absorbs a higher level of antibodies and is far less susceptible to scours and many other calfhood diseases such as coccidiosis, etc. To survive, and thrive--for every newborn calf:

  • Colostrum must be given first--it’s vitally important to make sure that the first feeding is colostrum and not milk or milk replacer. If the first feeding is milk or milk replacer, followed by colostrum, that colostrum will be poorly absorbed, even if it is given within the first 6 hours.
  • Colostrum must be given soon enough--immunoglobulins from the cow are concentrated in her colostrum. These immunoglobulins are very large molecules. The cells lining a newborn calf's intestine are ready to absorb these large molecules for the first 6 hours of life. But after that the calf's intestine starts to “close,” at which point the immunoglobulins are no longer absorbed.
  • Enough Colostrum must be given--it is recommended that a standard breed calf gets 2 quarts of good-quality colostrum by 2 hours of age, followed by 2 more quarts of colostrum by 6 hours of age--or, for miniature calves, make sure they get high quality colostrum at 8%–10% of body wt in the first 6 hrs after birth.
  • Quality of Colostrum: First-calf heifers typically have lower-quality colostrum than mature cows. Cows and heifers that leak colostrum just prior to or during parturition will also have lower-quality colostrum.

Commercial producers: Producers whose primary goal is to produce animals for herd replacement, feeding, and slaughter rather than breeding stock for sale to other producers. Commercial producers seek bulls or semen from seedstock breeders that have comprehensive programs designed to produce animals with optimum genetic merit for the combination of traits that increase efficiency and profit of their production system.

Compensatory gain: Rapid, subsequent gain of cattle that have been nutritionally deprived for some portion of their life. (Making up for lost time)

Complementary: The combining of breeds or individual animals that have characteristics that complement each other, thereby obtaining optimum progeny.

Complex Traits: Traits such as reproduction, growth, and carcass that are controlled by numerous genes.

Composite breed: A breed made up of combinations of other breeds. A composite breed has been in existence long enough to reproduce fairly predictably, but is not yet a long-established solid breed.

Conformation: A description of the shape of body parts of an animal. (Confirmation: eg. to confirm that you received or sent an order).

Congenital: A condition that was acquired during prenatal life and therefore exists at or dates from birth. The term is often used in the context of defects present at birth.

Continental (European or Exotic) breed: Breeds originally developed on the continent of Europe. Examples include Charolais, Chianina, Gelbvieh, Limousin, Salers, Simmental etc.

COOL or Country of Origin Labeling: “We have a government that allows the packer to bring an inferior meat product in from wherever they chose to…and they get to use our good name by putting a package on it that says product of the USA.” Right now imported cattle and meat, “inferior products from inferior countries,” that are processed in an American packing house are labeled product of the USA. ( The solution: Direct Marketing: Buy your beef locally, directly from a producer near you.

Corriente: 1). Old bloodlines of original type cattle in western America. 2). nondescript criollo bred cattle usually from Mexico. Often used in the U.S. for roping cattle.

Correlation: A numerical measure, ranging between: 1.00 and +1.00, describing how two traits are related. A high positive correlation means that as one trait increases, the other one usually does as well. For example, cattle with higher than average yearling weight generally will have larger mature size as well. When traits are negatively correlated, if one is above average, the other is likely to be below average. For example, as birth weight of a calf increases, calving ease is likely to decrease. A near zero correlation between traits means there is no particular relationship between them.

Council on Dairy Cattle Breeding (CDCB), Agricultural Research Service (ARS) and the Animal Genomics and Improvement Laboratory (AGIL) (and Animal Improvement Program — AIP (AGIL-West) perform rigorous research to develop and test new methodologies to maintain and ensure a high level of accuracy in the data implemented into the dairy animal database. Once these methods have been tested and confirmed, it is communicated with the CDCB and then applied to its system.. CDCB, in Bowie, Maryland, provides premier dairy genetic information services through industry collaboration centered around a mission to help optimize cow health and productivity in herds worldwide. CDCB is in charge and in full responsibility of the service portion of all genetic and genomic evaluations, including the computing and distributing of data, and maintaining the national dairy animal database. The CDCB drives continuous improvement and maintains the integrity of the world's largest animal database, building on a quality foundation with more than eight decades of recorded U.S. dairy animal performance. The CDCB is a collaborative effort between four sectors of the U.S. dairy industry: Dairy Records Providers (DRP), Dairy Records Processing Centers (DRPC), National Association of Animal Breeders (NAAB) and Purebred Dairy Cattle Association (PDCA).

Cow is a female bovine that has had a calf. (This term may also be used for other species.)

Crossbreed [noun] or Crossbreeding [verb]: The mating of animals of different breeds or subspecies, frequently resulting in heterosis (hybrid vigor) for many economically important traits. A crossbred cow is a crossbreed, which is the result of a crossbreeding. A black whiteface (BWF) is the most common & recognizable crossbreed. In straightbreeding, we try to achieve genetic improvement within the breed. If we use crossbreeding, we also receive two additional avenues for genetic improvement: 1) breed complementarity and 2) heterosis. Hybrid vigor (heterosis) eliminates inbreeding and seems to provide synergy for health, fertility and most production traits. An annual, rotational 3 way cross is the best way to maintain maximum hybrid vigor effects in a crossbred herd.

Culling: The process of eliminating less productive or less desirable individuals from a herd.

Cut: (1) [noun] "a cut" is a group of cattle separated from the herd for a reason, such as to sell. (2) First cut: the choice pick of the group. (3) [verb] the act of separating the cattle. (think; cutting horses) (4) Also: the process of castrating a male animal. Ranch wives often handle that job at brandings.

dressing %Cutability: An estimate of the percentage of salable meat (muscle) from a carcass versus percentage of waste fat. Percentage retail yield of carcass weight can be estimated by a USDA prediction equation that includes measured or estimated values for hot carcass weight, rib eye area, fat thickness, and estimated percent of kidney, pelvic, and heart fat.

CVI: The health certificate (Certificate of Veterinary Inspection) that is issued by a vet for an animal that travels over a state line when sold or shown; or for frozen genetics. The CVI must include a brand inspection if animal is leaving or entering a brand state. It must be signed by the federal vet for the state it is leaving if it is crossing international borders (Canada, Alaska or Mexico). Your veterinarian has access to all these details for your state.

go to top Dehorn: (1) [adjective] a dehorned bovine has had its horns removed (it is not a polled animal). (2) [verb] to remove horns from a calf. Dehorning a mature bovine is a fairly inhumane procedure (it causes excruciating immediate pain, and significant long-lasting pain with open-air sinuses that heal slowly). Dehorning is no big deal when taking off horn buds on a calf.

Dewlap: The loose folds of skin hanging off the front length of bovine necks. Clean-necked cattle have little or no dewlap. Bos indicus (Zebu breeds) of cattle have prominent loose dewlaps. In some areas, dewlaps may be notched at brandings as a permanent ownership mark.

Dimorphic: (1) The difference displayed between genders of the same breed. Differences include secondary sex characteristics, size, color, markings, and may also include behavioral differences. These differences may be subtle or exaggerated. One example is bulls being noticeably larger than cows. Another example is the color of mature bulls compared to cows. Bulls of some breeds (Tarentaise, Jersey, several French breeds, etc) are influenced by testosterone with dark or black coloring as they mature while the cows remain lighter, red or tan color with only black points. The opposite of dimorphism is monomorphism.

Disease: Any change in the structure or function of an animal’s body which interferes with that animal’s intended purpose.

Disease Transmission: (1) Horizontal Transmission--Contagious conditions contracted through close contact with other animals. More examples of horizontal transmission are farm practices (injections, tattooing, dehorning, rectal palpation, and blood collection), and transmission by vectors (flies, lice, worms, protozoa). (2) Vertical Transmission--disease contracted transplacentally from an infected dam to the fetus, intrapartum by contact with infected blood, or postpartum from the dam to the calf through ingestion of infected colostrum.

Disposition (temperament): A measure of an animal's docility, nervousness, wildness, or aggression toward unfamiliar situations, human handlers, or management interventions.

DNA (Deoxyribonucleic acid): The chemical compound that stores within each cell genetic information unique to an individual. A DNA molecule is composed of two strands of nucleotides bound to one another by chemical bonds between each complementary (A: T and G: C) base pair. The molecule has the appearance of a twisted ladder. The sequence of bases within DNA molecules determine amino acid sequences of proteins, control development, and establish the genetic potential for production of the individual.

DNA Base pair: The complementary bases found within a DNA molecule. There are four different bases: adenine (A), thymine (T), cytosine (C), and guanine (G). A always pairs with T, and C always pairs with G. The base sequence ultimately determines the effect of the gene.

DNA Marker: A specific DNA variation that can be tested for association with a physical characteristic (marbling, tenderness, etc.).

Dominant: An allele is dominant when its presence prevents a recessive allele from affecting the phenotype of an individual heterozygous at the locus in question. For example, the allele for polledness (P) is dominant to the allele allowing growth of horns (p), so an animal with the genotype Pp will have the polled form of the trait.

Double muscling: A simply inherited trait evidenced by an enlargement of the muscles with large grooves between the muscle systems especially noticeable in the hind leg.

Dressing percentage: (Chilled carcass weight/live weight) x 100. (eg. 768 lb. carcass ÷ 1200 lb. live weight = 64%)

Dual Purpose cattle: A biological type or breed of cattle that offers optimum and moderation in all production traits. Dual purpose cattle produce both meat and milk on small acreages for single families.

Dystocia (calving difficulty): Abnormal or difficult labor causing difficulty in delivering the fetus and/or placenta. Difficult births lead to increased calf and cow mortality and to more difficult rebreeding of the cow.

go to top Earmark: Method of marking cattle (and other livestock) by notching their ears in distinctive patterns. Usually used along with a brand, and is also registered to denote ownership and identification with the state, as is a brand. Many earmarks can be seen at a great distance. Earmarks can often be seen quicker than a brand (because a cow usually looks at you) and are a good aid in recognition and when sorting cattle on horseback.

Ear Tag: Another method of marking cattle (or other animals) by attaching a tag to their ears. Often vaccinations, breeding, and herd identification are information that are recorded using the tag numbers. (Negative side to this is that the tags can pull out and be lost.). Ear tags are used more for identification within a herd, than ownership.

Economic value: The net return for a one unit change (pound or percentage, for example) for an economically important trait under selection.

Economically relevant trait (ERT): Traits that are of direct economic importance to cattle producers.

ELISA test: An enzyme-linked immunosorbent assay (blood test) that evaluates a serum or plasma sample for the presence of a specific protein. A laboratory diagnosis.

Embryo transfer: Removing fertilized ova (embryos) from one cow (the donor), generally in response to hormone: induced superovulation, and placing these embryos into other cows ( the recipients). More calves can be obtained from cows of superior breeding value by this technique.

Endemic: A disease that is endemic is an ongoing disease found in a certain geographic region or in a specific species.

English breeds: see British breeds.

Environment: All external (nongenetic) conditions that influence the reproduction, production, and carcass merit of cattle. When environmental influences on phenotypic merit are not properly accounted for in genetic evaluations, they reduce the accuracy of breeding value estimation and of subsequent selection.

Enzootic: (1) the non-human equivalent of "endemic" (2) adjective; in a broad sense, "belonging to" or "native to", "characteristic of", or "prevalent in" a particular geography, race, field, area, environment, or native to an area or scope. (3) Adj.; of a disease that is constantly present in an animal community but only occurs in a small number of cases.

Epigenetic change: An alteration in gene expression without any changes to the DNA itself.

Epigenetic defect: A defect that affects gene expression rather than the gene itself.

Epidemiology: Factors influencing disease occurrence.

Epistatic genes: Some genes mask the expression of other genes just as a fully dominant allele masks the expression of its recessive counterpart. A gene that masks the phenotypic effect of another gene is called an epistatic gene; the gene it subordinates is the hypostatic gene. For an example, Dominant Red Variant in Holsteins affects dominant black; see coat colors in cattle.

Etiology: Causes of diseases

Exotic breeds: 1). Continental breeds, many are large framed. 2). breeds of cattle that originated in mainland Europe. 3). breeds or species of animals or bovine that are unusual to see, such as miniature cattle, yak, bison, beefalo, etc.

Expected Progeny Difference (EPD): The difference in expected performance of future progeny of an individual, compared with expected performance at some base point for the population (e.g., the average EPD is 0). The base point may either be fixed or floating. A fixed base sets the average EPD to 0 at a specific point in time (e.g., a specific year). A floating base point changes over years as the number of records analyzed increases. Fixed base points are recommended, especially for trait s that have intermediate optima. EPDs are estimated from phenotypic merit of an individual and all of its relatives and are estimates of one:half the breeding values. EPDs are generally reported in units of measurement for the trait (e.g., lb., cm., etc.).

go to top F-1 (first filial generation): Often used referring to offspring resulting from the mating of a purebred bull to purebred females of another breed. Using the P, F1, F2, F3…: The filial generation terminology is actually only used for a strict scheme of crossing: two animals of a different genotype, the P (parental) generation, are crossed with each other, the result is called an F (filial)1 individual. Two F1 individuals produce an F2 individual and so on. When an F1 individual is crossed with an individual of the P genotype, it is called a B (back-cross)1 individual.

Fat thickness: Depth of fat in tenths of inches over the rib eye muscle at the 12th rib. It consists of a single measurement at a point three-fourths of the lateral length of the rib eye muscle from the split chine bone.

Feed conversion (feed efficiency): Units of feed consumed per unit of weight gained or (more common in other countries) production of meat or milk per unit of feed consumed.

Feedyard: These outfits buy larger calves from the stocker to, “finish” or put the last pounds on before sending to market.

Fertilization (conception): The union of the male and female gametes to form a new, genetically unique individual. In cattle, sperm and egg cells with 30 chromosomes each combine to form a zygote with the 60 chromosomes normal to the species.

Finish: (1) [adj.] degree of fatness of an animal (2) [verb] completion of the last feeding phase of slaughter animals. Many homestead animals are grass finished.

Foundation bloodstock or foundation stock refers to animals that are the progenitors, or foundation, of a breed or of a given bloodline within such. Many modern breeds can be traced to specific, named foundation animals, but a group of animals may be referred to collectively as foundation bloodstock when one distinct population (including both landrace breeds or a group of animals linked to a deliberate and specific selective breeding program) provides part of the underlying genetic base for a new distinct population.

Frame score: A score based on subjective evaluation or actual measurement of hip height. This score is a reference to what height an animal will mature at, and in theory is expressed throughout the growth period fairly consistently. In carcass evaluation, frame score is related to slaughter weights at which cattle should grade choice or at which different groups of cattle should have comparable amounts of fat.

Freemartin: A freemartin is defined as a female that is born as a twin with a male and is sterile as a result of exposure to masculinizing hormones. When a connection between the two fetal circulatory systems develops early in gestation (anastomosis) that leads to the exchange of blood between the fetuses. Exposure to male hormones leads to underdevelopment of the female's reproductive tract. A DNA test that detects presence of Y-chromosome is available to confirm chimerism in the blood of mixed twin females suspect of being freemartins. Approximately 90% of mixed twin heifer calves are freemartins. Incidence of freemartinism in sheep is generally low (about 1%), but increased risk has been observed when litter sizes are four or more. Incidence of freemartinism in goats is also low (less than 1%), but also with increased risk in litter sizes of four or more. In goats, other intersex phenotypes can result from effects of the polled gene as well. (~ UC Davis)

Freshen: A fresh cow is a dairy term for a cow or first-calf heifer who has just given birth, or "freshened," and is ready to start milking after colostrum phase is over. Freshening refers to the fact that she has calved, and refreshed, or begun a brand new milking cycle, which usually lasts approximately 9 months when kept on an annual calving schedule.
Full: (see also "pure") is a word that is often used by miniature cattle breeders, sellers and buyers. "Full" does not have one official definition, and will mean different things to different people. Always ask for clarification in cases where the purity of an animal's bloodline matters.

Fullblood. (see also Purebred)
1) A recognized strain or bloodline(s) established by breeding individuals of unmixed lineage over many generations with a closed herdbook.
2) In most breeds, fullblood refers to an animal that is 100% pure--with no known crossbreeding or outside genetics mixed in since the first herdbook was established.
3) In many registries, fullbloods are DNA’d for proof of parentage to fullblood parents. Purebred (typically 87% & higher) usually denotes an animal that has some known hybridization in its pedigree.
4) The word fullblood is not used in some British breed herdbooks. In those breeds, 100% blood animals are called Purebred.

go to top Generation interval: Average age of parents when the offspring destined to replace them are born. It should be computed separately for male and female parents and then represents the average turnover rate of bulls and cows in the herd. When other factors are held constant, generation interval is inversely related to the rate of response to selection. That is, rapid generation turnover enhances rate of selection response.

Gene: A gene is a discrete segment of the DNA molecule, located at a specific site (its locus) on a specific chromosome pair. Two copies of each gene exist in each nucleated diploid cell in an animal. Only one gene of each pair is randomly transmitted to the offspring through the gamete. The unique nucleotide sequence of each gene determines its specific biological role. Many genes specify the amino acid sequence of a protein product. Others produce gene products that are involved in controlling metabolic and developmental events.

Gene marker: A specific sequence of nucleotides that is easily detectable and can be used to differentiate among alleles at a locus.

Genetic antagonism: A genetic correlation in which desirable genetic change in one traits is accompanied by an undesirable change in another. For example, because of the positive genetic correlation between milk yield potential and cow maintenance requirement, selection for increased milk would lead also to increased feed cost for maintenance.

Genetic correlations: Correlations between breeding values for two traits that arise because some of the same genes affect both traits . When two traits (weaning and yearling weight for example) are positively genetically correlated, successful selection for one trait will result in an increase in the other trait as well. When two traits are negatively genetically correlated (birth weight and calving ease, for example), successful selection for one trait will result in a decrease in the other. This is sometimes referred to a genetic antagonism between traits.

Genetic linkage map: A diagram showing where genes and markers are located on a chromosome and their relationship to one another.

Genetic trend: An estimate of the annual change in genetic merit of individuals within a breed for a trait. It is usually computed from the average difference in estimated breeding values of animals born in a series of adjacent years.

Genetics: 1) refers to study of genes, inheritance and the factors associated with them. 2) refers to frozen semen and embryos available from a sire, bloodline or breed.

Genome: The entire complement of DNA characteristic to individuals of a species.

Genotype: 1) The genetic makeup of an individua animal.
2) The two alleles present at a locus in an individual. For a locus with only two alleles, three genotypes are possible. For example, at the polled/horned locus in cattle,goggle-eyed two common alleles are P ( the dominant allele preventing growth of horns) and p (the recessive allele allowing horn growth). The three possible genotypes are PP (homozygous dominant), Pp (heterozygous or carrier), and pp (homozygous recessive). See Phenotype: The visible traits of an individual.

Genotyping (DNA marker testing): The process by which an animal is tested to determine the particular alleles it is carrying for a specific genetic test.

Gestation: The period of pregnancy or the period of time from conception until young are born, averaging about 285 days in cattle.

Goggle eyed (right): Having a predominate spot of pigment around the eye, an advantage with white face cattle. Dark pigmentation around the eyes helps reduce the occurrence of cancer eye and pink eye.

Grower/ Backgrounder/ Stocker: Guy who buys weaned calves to feed and grow. This is done in a variety of ways depending mostly on location, some are grazed and some are fed in lots.

go to top Half-sibs: Individuals having the same sire but different dams (or the same dam but different sires). Half-brothers, half-sisters, or half brother/sister.

Hanging weight: weight of a slaughtered animal after the head, skin, hooves and non-usable organs are removed.

Haplotype: A haplotype is a group of alleles in an organism that are inherited together from a single parent. A collection of specific alleles in a cluster of tightly linked genes on a chromosome that are likely to be inherited together—that is, they are likely to be conserved as a sequence that survives the descent of many generations of reproduction. Understanding Haplotypes: When the causative gene of a condition is not known, analysis of all genotypes in the breed may be able to identify a short section of the genome, known as a haplotype, that is expected to include the causative gene. While very valuable in controlling the spread of undesirable genes, identifying carrier animals based on haplotypes is not as accurate as results from a specific gene test. Since haplotype results are not 100% accurate, they are presented as carrier probability values ranging from 1% (likely free) to 99% (likely a carrier).

Harvest: To slaughter an animal.

Heat (estrous) synchronization: Through hormonal manipulation, causing a group of cows or heifers to initiate estrous cycles at approximately the same time.frame score is highly heritable

Heifer is a female bovine that has not had a calf.

Heifer calf is a female calf up until age of weaning.

Heritability: The proportion of the differences among cattle, measured or observed, that is transmitted, on average, to their offspring. Heritability of different traits vary from zero to one. The higher the heritability of a trait, the more accurately individual performance predicts breeding value and response to selection for that trait should be more rapid. For example, Frame score has a heritability estimate of .40, which is considered moderately to highly heritable. That means about 40% of a bull’s difference in frame score from the herd average will be passed on to his progeny. As such, frame score can be significantly (quickly) changed through selection achieved through sire selection. “Research conducted since the late 1940s has shown that nearly all economically important beef cattle traits are under some degree of genetic control, referred to as heritability, and expressed as a percentage of the total variation in a trait that is due to genetics as opposed to the environment.” ~ Harlan Ritchie. In general, these studies have shown that selection within a breed population for traits can be moderately to highly heritable (approximately 35 to 50%), moderately heritable (20 to 35%), to lowly heritable (under 10%).

Heritage Breeds of Cattle: Definition given by Livestock Conservancy (they use the term purebred for 100% pure or fullblood).

Heterosis (hybrid vigor): Amount by which the average performance for a trait in crossbred calves exceeds the average performance of the two or more purebreds that were mated in that particular cross.

Heterozygous: Genotype of two different alleles for a particular trait.
Homozygous: Genotype of two identical alleles for a particular trait.

High Altitude Cattle: Refers to cattle that have been bred to do well at high altitudes. High altitude cattle will score low numbers when PAP testing is performed above 6000 feet or more, and after the cattle have been in that high elevation at least 6 weeks. At altitudes of 5,000–7,000 ft, a normal mean PAP measurement should be 34–41 mmHg. The higher the altitude, the more accurate the PAP score is. High Altitude Disease, or brisket disease, results in pulmonary artery hypertension, which leads to congestive heart failure. It is an accumulative disease that happens over a period of time that worsens the longer susceptible cattle are kept at high altitude. There is a genetic component, that is neither breed nor gender specific. Susceptible cattle are at risk when running on mountain ranges above 5000 feet. Summer range brings the risk of bovine high altitude disease mostly in Colorado, Wyoming, New Mexico, Utah and Montana, a disease that causes 75,000 cattle deaths each year across the West. Research has shown that the heritability of HMD can be quite high, ranging from 40% to 85%. This indicates that cattlemen can successfully select against the disease by culling cattle with high PAP scores (selling them to low elevation ranches). In collaboration with Timothy Holt, D.V.M., an internationally known expert on brisket disease at Colorado State University, a Vanderbilt research group set out to identify a genetic component for this condition. Holt evaluated cattle herds for pulmonary hypertension and sent blood samples to the lab of John A. Phillips III, M.D., where DNA was extracted and analyzed. Phillips is David T. Karzon Professor of Pediatrics and director of the Vanderbilt Division of Medical Genetics and Genomic Medicine. Newman, Phillips and their colleagues, including Rizwan Hamid, M.D., Ph.D., Joy Cogan, Ph.D., and James West, Ph.D., discovered that most of the cattle with high-altitude pulmonary hypertension had a double mutation in a single gene that expresses hypoxia inducible factor, HIF2alpha. The Vanderbilt group is currently working on a test to help ranchers determine which cows carry the genetic susceptibility and should remain at low altitude.

Homestead Cattle: can be described as docile, efficient breeds of cattle with grassfed genetics that work well on small acreage. Not all, but most will be smaller, or shorter legged than modern or commercial maximum production breeds. Many are heritage breeds. Traits common to homestead & miniature breeds of cattle:

  • Produce milk, butter & cheese for a family
  • Many are dual purpose cattle that produce beef & milk for a family
  • Many are heritage bloodlines coming from old genetics
  • Not bred for single traits, nor for maximum high production on feed, commercial operations
  • Smaller cattle allow more animal units / acre (AUM)
  • Shorter legged (good feet & legs)
  • Larger capacity (deep bodies w/ wide-sprung ribs)
  • Grassfed genetics, producing tender, juicy excellent tasting beef on grass & hay
  • Efficient: Produce more pounds of beef / milk / acre with lower input
  • Browsers that do well on scrubby pastures
  • Rugged; Thrive in conditions where other cattle may struggle
  • Longevity - healthy producers for many years
  • Good for kids: Friendly, gentle natured, easy to work with
  • Good for beginners; quiet, easy on fences & equipment

Homozygote: A genotype in which the two alleles at a locus are the same, e.g. PP or pp.

Hot carcass weight: Weight of a carcass just prior to chilling.

Hybrid Vigor: (see heterosis).

go to top Inbreeding: Matings of parents more closely related than average in the population. Inbreeding decreases the proportion of heterozygous gene pairs in the offspring and increases the proportion of homozygous gene pairs. It increases the frequency of expression of genetic defects caused by recessive genes. Inbreeding may increase prepotency for simply inherited and highly heritable traits. Higher degrees of inbreeding can potentially lead to 3 main negative outcomes:
(1) inbreeding depression in production traits
(2) increased homozygosity of recessive genetic conditions
(3) a reduction in genetic diversity. ~ Southern Beef Technology Services (SBTS)

Inbreeding coefficient: A numerical measure, ranging from zero to 1.0, of the intensity of inbreeding of an individual. It represents the proportion of gene loci in the individual at which both genes are identical copies of the same ancestral gene.

Inbreeding depression: The reduction in performance level for many economically important traits that accompanies, on average, an increase in inbreeding coefficient.

Incomplete dominance: A situation in which neither of two alleles at a locus is fully dominant to the other. As a result, both are expressed. Typically the phenotype of the heterozygote is intermediate between that of the two homozygous genotypes.

go to top Karyotype: is a "picture" of the physical structure of the chromosome, usually taken from white blood cells. A trained cytogenticists can tell if there is anything abnormal, or missing from a normal example.

Kidney, pelvic and heart fat (KPH): The internal carcass fat associated with the kidney, pelvic cavity, and heart. It is express ed as a percentage of chilled carcass weight. The weight of the kidneys is included in the estimate of kidney fat.

go to top Lactation: The period of calf nursing between birth and weaning

Lethal gene: A gene or genes that cause the death of any individual in which they are expressed.

Libido: Sex drive. In bulls, the propensity to detect and mate estrous females.

Linebreeding: A form of inbreeding; the deliberate mating of closely related animals with the perceived objective to concentrate desirable characteristics of the progeny and to breed “consistency”.

Linecross: Offspring produced by crossing two or more inbred lines.

Linkage: The occurrence of two or more loci on the same chromosome within 50 cM linkage distance of one another. The significance of that is, when one linked loci is inherited, it is reasonably safe to assume the other allele is inherited along with it. If one is identified in genotyping, it is considered reasonable of the other (see marker).

Live weight: "On the hoof." The weight of an animal before slaughter.

Locus: The specific location of a marker or gene on a chromosome.

Long Yearling:
Technically, in official research and record-keeping, the age definition for a long yearling is >365 days of age; however on the ranch it is usually referring to cattle between 1 and 2 years of age (so, 18 mos or so).

go to top Maintenance energy requirement: The amount of feed energy required per day by an animal to maintain its body weight and support necessary metabolic functions.

Marbling: The specks of fat (intramuscular fat) distributed in muscular tissue. Marbling is usually evaluated in the rib eye between the 12th and 13th rib. It is a major factor in assigning USDA quality grade of a beef carcass.

Marker Assisted Selection (MAS) — The process by which DNA marker information is used along with phenotypic based expected progeny differences (EPDs) to select parents for the next generation.

Marker Assisted Management (MAM) — The process by which DNA marker information is used to assist in making management decisions such as sorting cattle entering the feedlot based on their propensity to meet certain grid criteria as determined by a genetic test.

Marker Panel — A combination of two or more DNA markers that are associated with a particular trait.

Mastitis: infection of the mammary gland that produces inflammation, redness, and off-color milk.

Maternal sires: Sires whose major function is to sire daughters (often crossbreds) with outstanding genetic merit for reproductive and maternal traits, adaptability to prevailing environmental conditions, and longevity. Such females would ideally be crossed to sire s of a terminal breed with all offspring marketed.

Maturity: An estimation of the physiological age of the animal or carcass. It is assigned by assessing muscle characteristics and the stage of bone maturity.

Mavericks: Range cattle that haven't been gathered and branded yet. Sometimes in remote, rough country an animal can be untouched for quite a while. Oreana is another (buckaroo) term used for an unmarked and unbranded bovine.

Mid Sized Miniature: This refers to one height division in the IMCBR registry that was set up to accept cattle that are not miniature cattle. The term "mid-sized miniature" is not used anywhere else.

Miniature Cattle: are small cattle of any breed (most are composites or mixed breeds) that range in height from Frame Score 1 and below.

Morphology: A parameter recorded during microscopic examination of semen in the standardized breeding soundness evaluation quantifying the visual characteristics of spermatozoa, expressed as the percentage that appear normal.

Motility: A parameter recorded during microscopic examination of semen in the standardized breeding soundness evaluation quantifying spermatozoa movement, expressed as the percentage demonstrating forward progressive motility.

Muley: "Cowboy slang" for polled. It can mean dehorned, but usually refers to a naturally polled cow.

Mutations: Genetic variations that spontaneously mutate in an embryo, in its genes, that cause abnormalities or genetic disease.

go to top

National Association of Animal Breeders (NAAB) is a non-profit organization, established in 1946 to unite individuals and organizations engaged in the artificial insemination of cattle and other livestock into an affiliated federation operating under self-imposed standards of performance and to conduct and promote the mutual interest and ideals of its members.

Natural beef: Refers to beef from cattle that have not been fed growth stimulants or antibiotics.

Neonate: Refers to the newborn calf.

Non-Additive Genetic Effects — Effects such as dominance and epistasis. Dominance is the interaction of alleles at the same locus while epistasis is the interaction of alleles at different loci.

Nucleotide — A structural component of DNA that includes one of four base chemicals: adenine (A), thymine (T), guanine (G), and cytosine (C).

go to top Offal: All organs and (non-meat) tissues removed from the inside of an animal during the slaughtering process.

Optimum level of performance: The most profitable or favorable ranges in levels of performance for the economically important traits in a given management system and environment. For example, although many cows produce too little milk, in every management system there is a point beyond which higher levels of milk production will reduce fertility and decrease profit.

Outcrossing or outbreeding: Mating together of animals that are not closely related. Mild outbreeding is illustrated by mating cows to a sire of their own breed but who is not closely related to them. Such outcrossing may widen the genetic base in a herd and reduce inbreeding accumulation. A higher level of outcrossing is illustrated by crossing two Bos taurus breeds. This generally would result in beneficial heterosis for economically important traits. Crossing of a Bos taurus to a Bos indicus breed is outcrossing of an even greater extreme. These two subspecies have been genetically isolated from one another for a very long time, so heterosis is expected to be greater than from a within subspecies cross. The widest possible outcross is between genetically distinct species, cattle and bison for example. Progeny from such crosses, even when viable, frequently are sub-fertile or infertile for a generation or two.

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

Ox is castrated bull that has been trained to work and is at least 4 years of age. Before it reaches age 4 it is a steer; and before it is weaned, it is a steer calf.

Oxen is the plural of ox.

go to top Packers; the big 4 that monopolize and control about 85% of the beef cattle marketing in the United States. “Farmers buy retail, sell wholesale, and pay the freight both ways ”— JFK; Because of the monopoly of Tyson, Cargill, National, and JBS over the beef market, ranchers raising cattle they have to take what they can get. The retail price of beef is no where near or related to the annual income made by cattle producers (

Palatability: Acceptable to the taste or sufficiently agreeable in flavor to be eaten.

Parturition: The act of giving birth; calving.

Pedigree: A tabulation of names of an individual's ancestors, often only those of the three to five closest generations. Pedigree information is used to establish genetic relationships among individuals to use in genetic evaluations.

Penetrance and expressivity: These two genetic terms are frequently misunderstood and they certainly cause confusion in diagnosing genetic disorders and their mode of inheritance. Penetrance refers to the proportion of individuals with a given genotype expressing any or all of the phenotypic features of the disorder, i.e. not all animals with a particular genotype show phenotypic manifestations (e.g. proportional dwarfism in Angus calves). In contrast, expressivity, or variability in clinical expression, describes the range of phenotypic effects in individuals carrying a given mutation. These two terms may overlap, particularly when used in terms of age of onset of a disorder. The penetrance and expressivity of the BD1 gene found in Irish Dexter and in percentage breeds that started with Dexter dwarfism DNA, explains why some BD carrier herds suffer more than others do.

Percent calf crop: The percentage cows an d heifers exposed to breeding within a herd and year that produce calves.

Performance testing: The systematic collection of comparative production information for use in genetic evaluation, selection decisions, and merchandising.

Phenotype: 1) The visible traits or outward appearance of an animal that can be measured. 2) The visible or measurable expression of a trait; for example color, height, performance, temperament. For most traits, phenotype is influenced by both genotype and environment. The relative degree to which phenotypic variation among individuals is caused by transmissible genetic effects is the heritability of a trait.

Phenotypic correlation: The net correlation between two traits caused both by genetic factors and environmental factors simultaneously influencing both traits.

Polled: Naturally hornless cattle. Having no horns (BFI definition includes scurs). The trait that is now commonly called polled was often referred to in old Scottish writings by the terms “doddies” or “humlies.” ~ Breeds of Beef and Multi-Purpose Cattle by Harlan Ritchie (https://www. Jan2009.pdf). Some sources cite studies that indicate horned cattle make better milk cows.

Postpartum: After the birth of an individual.

Postpartum interval: The number of days between parturition and the first postpartum estrus.

Prepotency: Often referring to a bull or stallion--the ability of a parent to transmit its characteristics to its offspring so that they resemble that parent, and one another, more than usual. An individual that is homozygous for a dominant allele will show prepotency for the trait controlled by that gene, but not necessarily for any other trait. Inbred cattle, having a higher than average degree of homozygosity, may be more prepotent than outbred cattle but only for simply inherited or highly heritable traits.

Pre-weaning gain: Weight gained between birth and weaning.

Producer: What is usually called a cow calf operation. Has cows and bulls, breeds the cows and raises the calves until weaning.

Progeny: The young, or offspring, of the parents.

Progeny testing: Evaluating the genotype or estimating the breeding value of an individual by evaluating the comparative phenotypic merit of its progeny.

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

Pure (see also "full"): A word that is often used by breeders, sellers and buyers. "Pure" does not have one consistent definition, and will mean different things to different people. Always compare definitions before making an investment when purity is a goal, or a factor in decisions.

Purebred (1) in most breeds this refers to an upgrade. Animals bred up or graded up to a known high percentage of purity, but always less than 100% pure (fullblood). Generally, 87.5% pure, or, a minimum of 7/8 for females and 15/16 for bulls, qualifies an animal as purebred. Read more here: Lowlines: Do the Math.

Purebred (2) one or two British breeds: In the rare registry that does not recognize the term "fullblood", an animal that is 100% pure (no crossbreeding or outside genetics since the breed began) may be called purebred. (IOW in a few British breeds purebred means the same thing as the word fullblood in other breeds.)

purity chart


go to top Qualitative (categorical) traits: Those traits in which there is a sharp distinction between phenotypes, such as black vs. red or polled vs. horned. Only one or a few pairs of genes are involved in the expression of many qualitative traits.

Quantitative traits: Those traits, such as weaning weight, in which there is no sharp distinction in the range of phenotypes, with a gradual variation from one extreme to the other. Usually, many gene pairs are involved as well as environmental influences affect variation for such traits.

Quantitative Trait Loci (QTL): A gene locus that has an effect on a quantitative trait. Often the actual nucleotide sequence is unknown, so selection is based upon genotype at a linked gene marker.

go to top Random mating: A system of mating in which 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.

Recessive: Recessive alleles are expressed only when homozygous. They must have been inherited from both parents before the phenotype can be expressed. At the locus for growth or absence of horns, for example, homozygous recessive pp individuals are horned whereas PP and Pp individuals are polled.

Reference sire: A bull that has previously been progeny tested and subjected to national cattle evaluation that is used concurrently with a test sire o r sires in a new progeny test program. Reference sires provide genetic linkages among herds and/or existing databases, allowing indirect comparison of the test sire with bulls evaluated at other places and times.

Rib eye area: Area in square inches of the longissimus muscle measured at the 12th rib interface on the beef forequarter. Rotational crossbreeding: Systems of crossing two or more breeds where the crossbred females are bred to bulls of the breed contributing the lowest proportion of genes to those females.

Rodear: To pull and work cattle out of a herd held by riders, such as in a fence corner where there is no corral. (a buckaroo term)

Rotational crossbreeding systems maintain relatively high levels of heterosis and allow for replacement heifers to be produced from within the system.

go to top Sanga cattle: (Bos taurus africanus) are taurine-indicine breeds of cattle indigenous to South Africa. They may have originated in that area independently. They have genetics that indicate they descend from Aurochs. They may also descend from African wild cattle crossed with zebuine bulls in East Africa during the 1500s. Sanga cattle are genetically distinct from European / near Eastern cattle, and from Indian Zebu cattle. Sanga cattle breeds include Abicar dairy cattle, the Afrikaner /Africander, Ankole, including the African Ankole Watusi strain from Burundi and Rwanda and in Kivu area of the adjoining Kivu area of eastern DR Congo, with massive horns. Not to be confused with the American breed Ankole-Watusi), the Drakensberger, the Nguni, and a few more.

Scrotal circumference: A measure of testes size obtained by measuring the distance around the testicles in the scrotum with a circular tape. Related to semen producing capacity and age at puber ty of female sibs and progeny.

Scurs: Horny tissue or rudimentary horns that are attached to the skin rather than the bony parts of the head but may become attached to the skull in older animals. There is a large variation in the size and growth rate of scurs. Bulls generally show more prominent scurs than heifers, but sometimes even in bulls the scurs can be so small, like a scab, that they are hard to see even on close examination. Careful examination at 12 months of age will usually reveal scurs on bulls if they are going to have them. Some females don't show scurs until they are 18 months of age or older. The inheritance of scurs is more complicated than that of the polled/horned gene because of sex differences and also horned animals cannot express scurs, even if they possess the scur gene(s), but yet the horned gene is needed for scurs to be expressed. Females must be a carrier of the horned gene and also must have 2 scur genes (one from each parent) for them to be scurred, however, bulls if they are a carrier of the horned gene need only 1 scur gene for them to be scurred, therefore, scurs are much more frequent in bulls than in heifers.

Seedstock breeders: Producers whose primary goal is to produce breeding stock rather than animals for feeding and slaughter. Progressive seedstock breeders have comprehensive programs designed to produce animals with optimum genetic merit for the combination of traits to increase downstream profit of commercial beef production.

Selection: Choosing some individuals and rejecting others as parents of the next generation of offspring.

Selection intensity: The selection differential measured in phenotypic standard deviation units of the selected trait. It is inversely proportional to the proportion of available replacements actually selected to be parents of the next generation. For example, with A.I. compared to natural service, only a small proportion of bulls needs to be selected, and the selection intensity, selection differential, and selection response will be high.

Serving capacity: A measure of the libido--the motivation, willingness, and ability of a bull to detect and service females in estrus.

Shrink: loss of weight. Commonly refers to the loss of liveweight when animals raised for beef are stressed before harvest, such as being worked or transported.

Slick: A cow (or horse) with no brand, earmark, or other identification of ownership.

Siblings (Sibs): Brothers and sisters of an individual; full sibs have the same sire and dam, paternal half sibs have the same sire but different dams, and maternal half sibs have the same dam but different sires.

Single Nucleotide Polymorphism (SNP) — Pronounced “snip.” A SNP is a single nucleotide change in a DNA sequence. For instance, AAGGTTA is changed to ATGGTTA. Here the second “A” is changed to a “T.” Not every SNP causes a physical change in an animal. SNPs occur in the hundreds of thousands across the genome.

Simple Traits — Traits such as coat color, horned status, & some diseases that are generally controlled by a single gene.

Sire summary: Published genetic predictions (EPDs) of sires for economically important traits from national cattle evaluation programs.

Sperm: A mature male germ cell.

St. Elmo's Fire: The eerie glow sometimes seen on cattle's long horns during a lightning storm. It is caused by brush like discharges of atmospheric electricity and commonly accompanied by a crackling or fizzing noise. The discharge also appears as a tip of light on the extremities of such pointed objects as church steeples or the masts of ships during stormy weather. The strange light was so named because St. Elmo is the patron saint of Mediterranean sailors, who regard St. Elmo's fire as the visible sign of his guardianship over them.

Steer: male bovine made infertile through castration, less than 4 years old. Most steers have short life spans: They are usually raised and harvested for beef. Steer may also be a castrated male bovine for a future ox that is less than 4 years old. In miniature cattle, a few lucky steers become pampered pets and pasture ornaments. When raised and trained for pulling agricultural implements, equipment or wagons, they are called oxen when mature (after 4YO).

Stocker/ Grower/ Backgrounder: Guy who buys weaned calves to feed and grow. This is done in a variety of ways depending mostly on location, some are grazed and some are fed in lots.

Stray: (like a lost dog) A bovine found strayed away from its range or property where it belongs. Cattle from several neighboring ranches (away) can show up mixed in during the season and need to be sorted and sent back to their proper homes. This is the main reason for branding and marking.

Super ovulation: Process by which a cow is treated with reproductive hormones to induce her to produce more eggs than normal.

Syndicate: Syndication occurs when more than two people decide to partner on a bull or female. It allows owners to share risk, investment, genetics and profits. Syndication can be a great way to add top line genetics to your herd, especially through ET and semen sales. It is just as important to pick your partners as it is to pick the animal to be syndicated. When syndicates don't work it is simply because of some of the people who were involved, much more than the wording of the agreement. Make sure you are very clear on what additional costs there will be and what each investor can expect in return... and you have to do this before you agree to be a part of the syndicate. Each partner should have equal rights, as sometimes the seller of the animal will become a partner in the syndicate then expect to call all the shots after the animal is sold. Syndication is not something you should agree to without careful consideration. Pick your partners and set up the rules and regulations well beforehand.... not as a bull or cow approaches the sale ring to sell.

go to top Tandem selection: Selection for one trait at a time. When the desired level is reached in one trait, then selection is practiced for a second trait.

Temperament (disposition): A measure of the relative docility, wildness, or aggress ion of an animal toward unfamiliar situations, human handlers, or management interventions. See temperament score charts here.

Terminal sires: Sires used in a crossbreeding system in which all progeny, both male and female, are marketed. For example F, crossbred dams could be bred to te rminal sires of a third breed and all calves marketed. Although this system allows maximum heterosis and complementary of breeds, replacement females must come from other herds.

go to top Ultrasonic measurements: A non-invasive method used to estimate carcass characteristics and reproductive events. It operates off the principle that sound waves echo differently with different densities of tissue.

Ungulate: Hooved animal.

Upgrade: 1.) noun, the resulting high-percentage breed from a breeding up program.
2.) verb, the process of breeding up from a crossbred to a high percentage breed animal, using another breed to start out with. Usually done in cases where importation of cattle or genetics is not feasible (see purebred).

USDA: The United States Department of Agriculture is a federal corporation that serves as a research, educational, and production environment, in relation to food, health, and environmental concerns.

USDA yield grade: Measurements of carcass cutability categorized into numerical categories with 1 being the leanest and 5 being the fattest. Yield grade and cutability are predicted from the same four carcass traits.

go to top Variance: Variance is a statistic that numerically describes the differences (variation) among individuals for a trait in a population. Without variation, no genetic progress would be possible, because genetically superior animals would not be distinguishable from genetically inferior ones.

Veterinary Officials are private veterinarians who are accredited by USDA. They receive additional training and are authorized to complete specific tasks and paperwork on behalf of APHIS. These include animal inspections, testing and certifications. Accredited veterinarians serve as the first line of defense in defending our country from emerging and foreign animal diseases. They also play a key role in facilitating live animal exports. This is important for livestock producers, as it is another source of revenue. It is also important for everyday citizens who want to bring their pets with them when traveling overseas. Neither of these can happen without health certificates. Accredited veterinarians are an important resource for APHIS, our nation’s livestock and poultry producers, and our country’s pet owners.

go to top Waddle: A method of marking cattle. Similar to what occur naturally in some hogs & goats, a waddle in cattle is formed by cutting a piece of skin so that it will grow into a distinctive hanging mark in a certain location. Used in conjunction with brands and earmarks. Waddles on dewlaps often are more visible than brands in cold weather country where the winter hair obscures the brand, and are useful for quick recognition and sorting.

Weaning: Pulling a calf off of its mother and allowing the cow to dry up her milk supply. Most cattlemen wean at 5.5 to 6 months. The calf's rumen is not fully developed until 4 to 5 months of age.

go to top Yearling: In official research and record-keeping, the definition for yearling cattle is from 271–365 days of age, and long yearling: >365 days of age.

Yield: (see dressing percentage) Percentage of the live animal weight that becomes the cutable meat carcass weight.

Yield grade (see cutability): A numerical score ranging from 1 (high yield) to 5 (low yield) reflecting the expected proportion of boneless, closely: trimmed cuts from the beef carcass. It is estimated from a USDA prediction equation that includes measured or estimated values for hot carcass weight, rib eye area, fat thickness, and estimated percentage of kidney, pelvic, and heart fat.


GLOSSARY of Technical Terms

for Commercial Cattle Industry & Research

not frequently used in Miniature Cattle operations

Across-breed EPDs: Formulas, equations, procedures or adjustment factors that allow direct comparison of EPDs from cattle of different breeds. They are based upon across-breed EPD adjustment factors which are added to EPDs provided by the separate genetic evaluation of each breed. The adjustment factors, which are updated each year, are based upon estimates of current performance differences among breeds and differences among breeds in genetic base for their evaluations.

Additive adjustment factors:
A numerical quantity added to an animal's record to reflect expected performance if the animal had belonged to some baseline group. For example, 60 pounds could be added to weaning weight records of steer calves out of two-year-old dams to represent expected weaning weight if their mother had been five to nine years of age.

Additive Genetic Effects: Average individual gene effects that can be transmitted from parent to progeny.

Adjustment Formulas: In the standard cattle industry, there is a lot of research and science put into formulas to adjust measured numbers to more fairly relate to each other across different breeds, ages and environmental conditions, with the goal of being able to more accurately compare between breeds and animals, most especially when culling or selecting breeding cattle.

Adjusted weaning weight (WW): An unshrunk, off-the-cow calf weight adjusted to 205 days of age and to a mature dam age equivalence.

Adjusted yearling weight (YW): An unshrunk weight adjusted to either 365, 452, or 550 days of age.

Animal model: A genetic prediction procedure in which EPDs are directly computed for all animals in the population.

Best linear unbiased prediction (BLUP): A genetic prediction methodology providing the most accurate and precise genetic evaluations possible, given the information and family structure that are available.

Central test: A comparison conducted at a single location where animals are assembled from several herds to evaluate differences in performance traits under uniform management conditions.

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

Contemporary group: In research this refers to a group of cattle that are of the same breed and sex, are similar in age, 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.

Decision Evaluator for the Cattle Industry (DECI): A decision support system available through the U.S. Meat Animal Research Center that simulates the impact of alternative breeding or management strategies on production and profit within a producer's herd.

Deviation: The difference between an individual record and the average for that trait in the individual's contemporary group. For all animals within a contemporary group, these differences sum to zero when the correct average is used. A ratio deviation is an individual's ratio minus the group average ratio or 100 when expressed in percentage units.

Direct effect: For weaning weight that portion of preweaning growth that is due to the calf's genetics (see Maternal Effect).

Direct EPD: An EPD representing the effect of the individual's own genes on the trait of interest. A calving ease direct EPD, for example, represents calving ease of an individual's progeny. See also Maternal EPD.

Economically Relevant Traits (ERTs): Traits such as reproduction, growth, and carcass. These are usually not simple traits, but are usually complex traits that are controlled by numerous genes.

Effective progeny number (EPN): An indication of the amount of information available for estimation of expected progeny differences (EPDs) in cattle evaluation. It is a function of number of progeny of a parent 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 of progeny because the distribution of progeny is never ideal.

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 itself and sometimes performance of genetically correlated traits. EBV combines available performance information on the individual and sibs and the progeny of the individual and other relatives. Expected progeny differences (one: half EBV) have replaced EBV's in most breed association programs.

Fingerprint (DNA): Pattern of DNA fragments unique to an individual. Often produced by using restriction enzymes to cut the DNA into fragments at specific sequences of nucleotides. Using electrophoresis, these fragments can be sorted and then visualized, forming a unique “fingerprint" for each different animal.

General purpose breed: A breed with acceptable genetic merit in reproductive, maternal, growth, and carcass traits, but not specialized in either terminal or maternal characteristics. Such breeds frequently are used in rotational crossbreeding programs.

Indicator traits: Traits that do not have direct economic importance, but aid in the prediction of economically important traits.

Independent culling levels: Selection based on cattle meeting specific levels of performance for every trait included in a selection program. Equivalently, culling based on the failure of cattle to meet the required standard for any trait in the program. For example, a breeder could cull all heifers with weaning weights below 400 pounds (or those in the bottom 20% on weaning weight) and yearling weights below 650 pounds (or those in the bottom 40%).

Integrated resource management (IRM): Producing beef cattle in a manner that efficiently, profitably, and sustainably uses available human and physical resources.

Interim EPD: An expected progeny difference computed from an individual's own performance information and/or the EPDs of its parents. Interim EPDs may be used to support selection and merchandising decisions before EPDs from regularly scheduled national cattle evaluations become available.

International cattle evaluation: An evaluation utilizing data from more than one country, allowing comparisons of estimated genetic merit of cattle across countries.

Marker Assisted Selection (MAS): The use of genetic markers to select for specific alleles at linked QTLs and therefore specific traits.

Maternal effect: For weaning weight, the dam's maternal ability which influences preweaning growth.

Maternal EPD: An EPD representing the effect of the genes of an individual's daughters on the trait of interest. A calving ease maternal EPD, for example, represents the ease with which an individual's daughters calves are born. See also Direct EPD.

Maternal heterosis: Amount by which the average performance for a trait in the progeny of crossbred cows exceeds the average performance of progeny of purebred cows of the two or more breed ancestors of the crossbred cows.

Most Probable Producing Ability (MPPA): An estimate of a cow's future superiority or inferiority for a repeatable trait (such as progeny weaning weight) based upon the cow's past production in comparison to her contemporaries, her number of past records, and the repeatability of the trait in question.

Multiple breed evaluation: A genetic prediction simultaneously utilizing data from more than one breed or crossbred group. It accounts not only for differences among animals in transmissible genetic value (EPDs) but also in breed differences and heterosis effects.

Multiple trait evaluation: A genetic prediction which uses phenotypic measurements of two or more genetically correlated traits (birth weight, weaning weight, and post: weaning gain, for example) to simultaneously estimate breeding values for each of the traits. Compared to single trait evaluations, multiple trait evaluations produce EPDs with slightly higher accuracy and less bias from selection.

Multiplicative adjustment factors: A numerical quantity by which an animal's record is multiplied to reflect expected performance if the animal had belonged to some baseline group. For example, if calves from mature dams weighed, on average, 8% more than calves from two-year-old dams, the multiplicative factor to adjust calves from two-year-old dams to a mature age of dam equivalent would be 1.08. The use of multiplicative adjustment factors affects variability in the trait after adjustment, inflating it when the multiplicative factor is greater than 1.0 and deflating it when less than 1.0.

National Cattle Evaluation (NCE): Genetic evaluations conducted by breed associations to compute estimated genetic merit of a population of animals. Carefully conducted national cattle evaluation programs give unbiased estimates of expected progeny differences (EPD's). Cattle evaluations are based on field data and use on information from the individual animal, relatives, and progeny.

Nonadditive gene effects: Effects of specific gene pairs or combinations of gene pairs. Nonadditive gene effects occur when the heterozygous genotype is not intermediate in phenotypic value to the two homozygous genotypes. Undesirable homozygous gene combinations lead to inbreeding depression in inbred populations; whereas favorable heterozygous gene combinations lead to heterosis in outbred herds.

Number of contemporaries: The number of animals of similar breed, sex, and age against which an animal was compared in performance tests. The greater the number of contemporaries, the greater the accuracy of comparisons.

Performance data: The record of the individual animal for reproduction, production, or carcass merit. The most useful performance records for management, selection, and promotion decisions may not be the same for all seedstock breeders and may be different for seedstock breeders and commercial cattle producers.

Performance pedigree: A pedigree that includes performance records of the individual, ancestors, relatives, and progeny in addition to the usual pedigree information. Expected progeny differences may also be included.

Predictability or Possible change: The amount by which an individual's current EPD might reasonably be expected to change (either upwards or downwards) as more information becomes available in subsequent national cattle evaluations. This measurement of error in prediction decreases as the number of offspring per sire increases.

Rate of genetic improvement: The amount 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.

Ratio: An expression of an animal's performance for a particular trait relative to the herd or contemporary group average. It is calculated for most traits as:

Individual Record X 100.
Group Average

Regression: A measure of the relationship between two variables expressing the expected change in one of them per unit change in the other. Using regression methods, the value of one trait can be predicted by knowing the value of others. For example, easily obtained carcass traits (hot carcass weight, fat thickness, rib eye area, and percentage of internal fat) are used to predict percent cutability.

Relationship matrix: A table that stores numerical values for the genetic relationships among pairs of animals. It is used to predict genetic merit of each animal from its own phenotypic merit and that of all of its relatives.

Relative economic value: The amount by which net income to the cattle enterprise will change, per unit change in genetic merit for a trait.

Residual Feed Intake (RFI): The difference between actual and expected feed intake (e.g., actual feed intake: predicted feed intake estimated by multiple regression of feed intake on average daily gain and mid: weight during a test period as independent variables).

Selection differential (reach): The difference between the average for a trait for selected cattle and the average of the group that was available for selection. The expected response to selection for a trait depends on selection intensity and accuracy of EPDs.

Selection index: A formula that combines performance records from several traits or different measurements of the same trait into a single value for each animal. Selection indexes assign relative emphasis to different traits according to their relative net economic importance, their heritability, and genetic associations among the traits.

Sire x environment interaction: When the difference in progeny performance among sires is dependent upon some factor of the environment under which the progeny were compared. For example, sires might rank differently for progeny performance in different contemporary groups, herds, or regions.

Sire model: A genetic prediction procedure in which EPDs are directly computed for all sires with progeny in the population.

Standardized performance analysis (SPA): A set of programs that allow producers to collect, process, and interpret information on biological efficiency and economic returns to a seedstock or commercial beef production enterprise.

Stayability EPD: The expected difference among individuals in the probability that a daughter will stay in the herd to at least six years of age. Because the majority of cows culled before the age of six are open, the EPD is primarily a prediction of sustained fertility in female offspring.

Systems approach: An approach to evaluate breeding programs and selection schemes that involves assessment of alternatives in terms of their net impact on all inputs and output in the production system. This approach specifically recognizes that intermediate levels of performance in several traits may be more profitable than maximum performance for any single trait.

Threshold model: Statistical procedures for analyzing traits that are expressed in an all-or-none fashion (alive vs dead or pregnant vs open, for example) but that probably are affected by environmental factors and by genes at many loci. When genetic predictions are conducted for such traits using the threshold model, resultant EPDs reflect the expected proportion of an individual's progeny that will or will not express the trait.

Weight per day of age (WDA): Weight of an individual divided by its age in days.

Whole Herd Reporting (WHR): An inventory based performance recording system in which the production of all animals in a breeding herd and the performance of all progeny are accounted for annually. In calf-based systems, by contrast, progeny performance data may be recorded selectively but production information will not gathered on females that do not produce live calves. An inventory based Whole Herd Reporting system is necessary to acquire data for genetic evaluation of some reproductive traits.

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Beef Improvement Federation of North America
Beef Cattle Institute, Kansas State University
ADBA American Dexter Breeders Association
Texas Cooperative Extension and Texas AMU
Harlan Ritchie, Michigan State Univ Ag Dept
University of Tennessee
The Denver Post
Cowboy Showcase of Beef Cattle Ritchie
Schmutz, Sheila M. (2015). “Genetics of Coat Color in Cattle”, Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, Canada
Dun Galloway Genetics; a discussion of effect on phenotypical expression;
©Alan S. Bias, Permission granted for nonprofit reproduction or duplication of photos and text with proper credit for learning purposes only. March 16, 2015

homestead cattle green bar graphic

go home little cow

owner: Homestead Cattle Association
published online: January 2018
editor: Donna Grace