In addition to everything below, there are about a thousand specific terms to describe the conformation and physical aspects of a horse. Check them out if you're interested at Equibase.
Typically, when selecting a stallion to breed a mare to you have to take a close look at a large number of things. I can’t cover all of them. But briefly:
Price: You shouldn’t overbreed your mare, meaning if she’s not amazing, don’t breed her to the $100k stallion. Understanding your mare’s limitations is a hugely important factor. Else you’re just throwing good money after bad.
Conformation: If your mare is crooked, best breed to the straightest thing you can find. While it is not a science, understanding that downplaying faults is important is crucial. This also plays into size. If your mare is small, going to the biggest stallion you can find is probably a waste. Her physical limitations won’t get you a huge foal. Breed to something size appropriate.
Distance: You have a speed ball mare. So do you breed to Speightstown to get something that will run 21s through 5.5f? Or maybe think about something with a little more distance to be able to try to stretch sprinter speed out to mile. Personally, I’m all about accentuating strengths.
Nicks: Personally I don’t think the Nicking system is the best, but it still is a baseline for the industry to compare matings. So you have to play ball at some point with the system. An “A” rating will go a long ways to convincing yourself that a specific pairing is the best.
List of Commonly Used Breeding/Pedigree Terms:
Age: Every thoroughbred’s birthday is January 1st.
- Suckling: Still nursing from their dam (also just called a baby)
- Weanling: Has been separated from mother, but has not turned 1 yet
- Yearling: Has celebrated 1 birthday, is not normally in training.
- Colt/Filly: a 2, 3, or 4 year old
- Horse/Mare: a 5 year old (or older) horse.
- Gelding: A male horse of any age that has had its testicles removed.
Barren: a mare that could not get in foal the previous breeding season and is currently open.
Black type: Indicates a stakes winning/placed horse in a pedigree. Typically will specify the race if a graded/group event. More black type can typically indicate a better pedigree.
Bloodstock Agent: An authorized agent that will act on behalf of his/her clients in the purchase and sale of horses both privately and while at auction. Can prep horses for sales. Works on commission.
Book (aka a Stallion’s book): The schedule of mares that are due to be bred to any stallion. Typically, the most popular stallions will cover anywhere from 50-150 mares. A full book denotes that the stallion’s handlers have successfully courted and received a large number of high quality mares.
Breaking a horse: The process by which a 2 year old become trained to accept a rider, exit the starting gate, and become accustomed to racing. Is conducted at off-track training facilities.
Bred (KY bred, FL bred, etc): Different states have different rules, but typically (state) -bred means a horse is bred in a state/country if it is foaled there.
Broodmare: A mare solely used for breeding.
Broodmare Sire (aka Damsire): The sire of the dam of any horse.
By: i.e. By Mr. Prospector means a given horse is sired by Mr. Prospector. X horse is by Y horse means Y is X's sire.
Chef-de-race: Recognized sires that are considered “superior”
Commercial Breeder: An owner that is breeding foals for the express purpose of selling either privately or at auction before the foal reaches the track.
Cribbing: Horses that bite fences, stall walls, etc in an attempt to suck air into their stomach.
Dam: the mother of any horse
Dosage: Although there are actually many "Dosage theories," the one most commonly thought of as Dosage is the one as interpreted by Dr. Steven Roman. A variation of Dr. Franco Varola's work on pedigree analysis, the system identifies patterns of ability in horses based on a list of prepotent sires, each of whom is a chef-de-race. The Dosage system puts these sires into one of five categories brilliant, intermediate, classic, solid and professional, which quantify speed and stamina. Sires can be listed in up to two chef-de-race categories. Each generation of sires is worth 16 points, divided up by the amount of sires, i.e., the immediate sire is worth 16 points while the four sires four generations back are worth four points apiece. Dosage index (DI) is a mathematical reduction of the Dosage profile to a number reflecting a horse's potential for speed or stamina. The higher the number, the more likely the horse is suited to be a sprinter. The average Dosage index of all horses is about 4.0. h/t to Equibase.
Female Tail: The direct female lineage of the horse in question. Typically a good indicator of the quality of the family in terms of production since the broodmares are a limited quantity while sires can have hundreds of foals a year.
Founding Sires: Every single thoroughbred must be able to trace their lineage back to the three original sires: the Darley Arabian, the Byerly Turk, and the Godolphin Barb.
Full Brother/Sister: Horses that share the same sire and dam. Half brother/sister denotes sharing only the same dam. Sharing only the same sire does not make siblings “halves”
Homebred: A horse that is bred and raced by its current owner.
In foal: Currently pregnant.
Inbred: Where the same horse appears multiple times in a pedigree. Typically, anything further back than the 5th generation is ignored. For example, a 3x3 inbreed to Mr. Prospector would have him in the third generation (Great-grandsire) on the sires (top half) side an on the dams (bottom half) side as the great-granddam sire. 2x4, 3x3, and 4x2 inbreeds are commonly seen as the same amount of inbreeding, though that is debated. 2x3, 3x2, and 2x2 inbreedings are extremely rare and are not commercial. For multiple inbreeds in a pedigree the following formula is used: 3m,4m X 3f. “m” is male, “f” is female lineages. Inbreeding is used in the hope that having more genetic contributions from a great racer/producer that you will see greater similarity to that horse. Results are murky at best if this is true.
Intact: Male horses that have not been gelded.
Live Foal Stands and Nurses (LFSN): A condition to a stallion season contract that there is no stud fee due if you do not get a Live Foal that both stands up and nurses the dam. This ensures that offspring are viable prior to payment of the stud fee.
Nicking: A process which compares all previous, registered foals/runners with any prospective cross the breeder is interested in. Typically graded from A+++ to D. The higher the grade, the more stakes winners have been produced on similar crosses. At a minimum, this compares a sire crossed with mares from one broodmare sire. More typically, due to sample size limitations, the crosses will be composed of sire and grandsire crossing with Broodmare sire and the broodmare sire’s sire. Complicated yes, but it is an easy way to see the productivity of certain families when crossed with certain sires. Can be found at Enicks and TrueNicks websites.
Open: Mare currently not in foal.
Outcross: a horse with no inbreeding within 5 generations of its pedigree. Not typical since major sire lines typically dominate regional breeding. For instance in NA to find a horse with zero Mr. Prospector is near impossible. In EU, the same can be said for Sadler's Wells. And in JPN, nearly every serious runner has Sunday Silence in its pedigree. To find two horses for breeding without these kinds of major influences is difficult.
Out Of: i.e.out of Bayakoa, means a given horse's dam is Bayakoa. X horse is out of Y horse means Y is X's dam. Alternatively you can see it as Shanghai Bobby is by Harlan’s Holiday out of an Orientate mare (Steelin’). [horse “by” sire “out of” damsire (dam)]
PedigreeQuery.com: The database that contains the pedigree of every registered thoroughbred and quarterhorse. Also contains information on winnings, stakes races, progeny, and progeny earnings. However, it must be manually updated, so cross referencing with Equibase is highly recommended. http://www.pedigreequery.com/
Pinhooker: A commercial buyer who purchases a horse at sale with the intentions of reselling. Often seen at the Keeneland September Yearling Sale where a pinhooker will then resell at Ocala for the 2 Year Olds in Training Sale.
Reines-de-Course: The identified preeminent foundation mares that make up the genesis of families of dominant races. Their actual effects in pedigrees are disputed, but they will normally have outstanding production records. Denoted in PedigreeQuery.com with a green star.
Ridgling: Horse only has one descended testicle.
RNA: Reserve Not Achieved. Used in auctions where the final bid does not reach a predetermined price. Typically set at the stud fee for younger horses and mares in foal, it can be up to 7 figures in certain cases.
Service: Date of last mating. For mares in foal you can determine an approximate delivery date quickly with the information.
Slipped: Mare lost a foal due to a spontaneous abortion.
Stakes placed: Horse finished second or third in a graded or listed stakes event. See Black Type.
Stallion: Male horse used for breeding.
Stallion Register: The site administered by Bloodhorse that is the main source for all information for any stallion. http://www.bloodhorse.com/stallion-register/
Stallion Share: A lifetime breeding right to a stallion. Only one mare per share can be used in a season. Typically awarded to Trainers and Jockeys of major stallions upon retirement. Can be resold at any value the share holder wishes.
Stallion Season: One breed to one stallion in a given year.
Stud Fee: The contractual price for one breeding. Can range from free to $150,000 for one foal. Typically, stallion operations can and will offer deals to reduce fees in exchange for bundling mares, mares with great pedigrees, or for other promotions like Spendthrift runs.
Tattoo: The permanent tattoo indicating the official registered status of any horse with the Jockey Club. To race, all thoroughbreds must have a tattoo inside their upper lip.
Teaser: A stallion used to prepare mares for breeding. Typically not an actual stallion at the stud farm, instead, it is just another intact horse.
Check out Equibase for more horse racing technical terms.