GLOSSARY OF SHEEP TERMS
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ADJUSTED LOIN EYE AREA - Loin eye area adjusted to a constant weight or age for the purpose of comparison. ADJUSTED WEIGHT – Weight that has been adjusted for age, sex, birth type, rearing type, and/ or age of dam for the purpose of comparison. ALLELE - one of two or more versions of a particular gene. An individual inherits two alleles for each gene, one from each parent. ARTIFICIAL INSEMINATION – The process where semen is placed in a ewe’s uterus in an attempt to achieve pregnancy without a ram present. BANDING - Applying rubber bands to the tail for docking or to the scrotum for castrating. BIRTH TYPE – Litter size (single, twin, triplet, etc). BIRTH WEIGHT – Weight of lamb at or very near birth. BODY CONDITION SCORE (BCS) – Scoring system used to describe bodily energy stores (fatness) of breeding animals. In sheep the BCS ranges from 1 to 5, with one being extremely thin and 5 being obese. BODY WALL FAT THICKNESS - Total tissue thickness measured between the 12th and 13th ribs, 4.5 inches from the center of the backbone. Used as an additional measure of fatness in a lamb carcass. BREAK JOINT - Cartilaginous area of the cannon bone that has not yet ossified. This joint fuses with age into a spool joint. Carcasses with a break joint are classified as a lamb where as carcasses with a spool joint are classified as mutton. BREED IMPROVEMENT – Strategies
ENTROPION - A genetic defect observed in newborn lambs where the eyelid folds inward causing eye irritation. EWE - Female sheep. EYE MUSCLE DEPTH – The depth of the loin eye muscle measured ultrasonically between the 12th and 13th ribs. Eye muscle depth measures muscle and more muscular caracasses are higher yield carcasses. F1 - Progeny resulting from the mating a purebred ram and a purebred ewe of different breeds. F2 -Progeny resulting from an FI sire and an F1 dam. FAMACHA - Parasite control regiment for controlling and treating Haemonchus Contoritus (barber pole worm). Uses eye color chart to predict level of anemia in the animal. FAT DEPTH - Subcutaneous fat thickness measured between the 12th and 13th ribs, over the mid-point of the rib loin eye muscle perpendicular to the outside surface of the fat. FECAL EGG COUNT - Number of worm eggs in a gram of feces – used to determine parasite load in a sheep. FEED EFFICIENCY – A measure of how effectively an individual sheep converts feed to product. Typically expressed in pounds of weight gain per pound of feed fed and/or the related cost of that gain. FIBER COLOR – Wool of any color other than white (black, gray, silver, brown, red, etc.) FINISH – Amount of fleshing and fat thickness, used to determine an animal’s readiness for harvest.
for improving the genetic and phenotypic quality of a breed and enhancing its acceptance within the sheep industry. These concepts are central to the United Suffolk Sheep Association’s mission and vision statements. BREED CHARACTER – Long- established phenotypic characteristics of a sheep breed, defined by breeders and/or breed associations. CARRIER - A heterozygous animal with one recessive and one dominant allele for a particular gene pair. The expression of the recessive allele is not visually observable due to the effect of the dominant allele. CHROMOSOME - An organized package of DNA (genes) found in the nucleus of the cell. Sheep have 27 pairs of chromosomes. CIDR – “Controlled Internal Drug Release”- an intravaginal progesterone implant used to induce and synchronize estrus in ewes. CLOSED FLOCK - An existing flock that does not introduce any outside animals, often for biosecurity reasons. Outside genetics, if used, are introduced via artificial insemination. CLUB LAMB – A youth oriented, terminal project (4H or FFA) lamb of either sex (typically a wether) that is shown as a market lamb and evaluated based on a combination of body composition (muscle and fat), conformation, and other characteristics. CODON - A specific location on a chromosome that forms a unit of genetic code. For example, the alleles present at Codon 171 determine the level of a sheep’s susceptibility to scrapie. In this case it is described as RR, QR (least
susceptible to Scrapie) or QQ (most susceptible to Scrapie) COEFFICIENT OF RELATIONSHIP – A measure of genetic similarity between two individuals, as predicted by pedigree. COLOSTRUM – Antibody-rich first milk that a ewe produces in the first 24 hours after giving birth. The antibodies are most readily absorbed by the lamb in the first 24 hour time frame. CONTEMPORARY GROUP – A group of lambs of similar sex and age that have been fed and managed the same way. COMPOSITE BREED – A new breed formed by crosses between two or more pure breeds, followed by subsequent matings among the crosses to stabilize the composite. CREEP - Supplemental feed provided to lambs that are still nursing, typically in an area that only the lambs can access. CROSSBREEDING - Mating of different breeds to take advantage of the strengths of each breed and gain hybrid vigor. CULL – An animal that has reached the end of its productive life and is removed from the breeding flock or sold for harvest. DAM - Mother of offspring. DATA COLLECTION – Gathering and recording data on traits important to your flock. Data may be submitted for across- flock genetic evaluation through central programs such as NSIP. DNA MARKER – DNA is mapped by finding the combination of single nucleotides that make up the DNA or the genome, a gene or DNA sequence with a known location on a
chromosome that is used to identify or track inheritance of nearby genes. DNA SAMPLE – A blood or tissue sample used for DNA testing, the commonly used sampling methods are blood tubes, blood cards and ear tag tissue samples. DOMINANCE - A single copy of a dominant allele typically masks or overrides the expression of a different allele in the same gene pair. DOMINANT TRAIT – An inherited characteristic that is expressed in the appearance of an animal that has one or two copies of a dominant allele in a gene pair. DRESSING PERCENTAGE - Hot carcass weight divided by live weight immediately prior to harvest; the normal dressing percent range for sheep is 44-56%. DYSTOCIA - Difficulty in giving birth. DWARF GENE – A genetic defect that is characterized by the affected offspring being proportionally reduced in frame size and weight. It is noted as FF (homozygous dominant, free non-carrier), FD (carrier) and DD (homozygous recessive, dwarf). ESTIMATED BREEDING VALUE (EBV) - An estimate of an animal’s genetic merit for a particular trait based on the individual’s performance and the performance of relatives. An EBV becomes more accurate in time as the database accrues more information on related animals across different flocks and environments. EMBRYO TRANSFER - Implantation of embryos or fertilized eggs from a “donor” ewe into a surrogate or “recipient” ewe.
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