Glossary of Breeding Terms

As breeders book their mares and start to see their foals being born, now is a good time to brush up on some breeding terminology you might come across when discussing your horses.  For those new to the breeding game, this information might help to make sense of the plethora of information you will receive when deciding where to send your mare.

Keeping track of what’s what…

COLT – A male horse under the age of four years which has not been gelded.

FILLY – A female horse under the age of four years.

FOAL – The offspring of a dam.

GELDING – A male horse of any age which has been castrated.

RIG – A male horse which has a testicle that has not descended into the scrotum. Gelding of a rig requires a surgical operation.

STALLION – Male horse over three years old which has not been castrated, also known as an ‘entire’.

WEANLING – Horse under the age of one year (at 1st August) which has been weaned from its dam.

YEARLING – A horse born after 1st August officially becomes a yearling on the following 1st August. Tingling Sensation x Primus_08 filly2


Keep it in the family….

DAM – The mother of a horse.

DAM SIRE – Also known as the broodmare sire – the sire of the dam of a horse, or maternal grandsire.

FIRST DAM – The mother or ‘dam’ of a horse.

FIVE EIGHTHS SISTER / BROTHER – Where five of the eight great-grandparents are the same as those of another horse.

FULL SISTER / BROTHER – A horse by the same sire and same dam.

HALF SISTER / BROTHER – A horse from the same dam. A horse by the same sire is not termed a ‘relation’ – it is referred to only as being ‘by the same sire’. This is because a stallion may have 100-odd progeny every year for many years, whereas most mares will only have 10 or so foals in their lifetime, making the relationship more relevant.

SECOND DAM – The grand-dam (grandmother) on the female side of the pedigree.

SIRE – Father of a horse.

THIRD DAM – The great grand-dam on the female side of the pedigree.

THREE QUARTER SISTER / BROTHER – Where a horse is by the same sire and the dam is a half sister to the dam of the other horse (three of the four grandparents are the same).


What’s in a pedigree?

BY – A horse is ‘by’ a certain sire – this term is never used for the dam.

CATALOGUE-STYLE PEDIGREE – This is where a pedigree is laid out as it is in a sales catalogue.  There is a tabulated pedigree at the top, followed by a description of the sire’s results at stud, then detailed information on the dam including her race record and her other progeny.  This is then followed by similar information on the second and third dams.

DISTAFF – The female or dam’s side of the pedigree.

FROM – A horse is ‘from’ or ‘out of’ a certain dam – these terms are never used for the sire.

INBREEDING – Mating a mare to a stallion who carries the same individual within the first three generations is ‘inbreeding’ to that individual.

LINE BREEDING – Takes over as an extension of inbreeding – the reinforcement of ancestor’s further back in the pedigree.

NICKS – Crosses (usually of a sire over a broodmare sire) which have proven to have an above average record for producing stakes winners.

OUT OF – A horse is ‘from’ or ‘out of’ a certain dam

PEDIGREE – Family tree of a horse – in the Thoroughbred it can be traced back to the creation of the breed two hundred years ago. Modern day Thoroughbreds can trace their ancestry back to one of three particular foundation stallions, the Godolphin Arabian, the Byerley Turk and the Darley Arabian.

PINHOOKING – The purchase of a weanling with the intention to re-sell it as a yearling for a profit.

PROGENY – The offspring of a horse.

SEX BALANCED – Usually referred to when inbreeding, if the individual to which the horse is inbred (or closely line bred) appears through both a son and a daughter, it is said to be ‘sex balanced’.

TABULATED PEDIGREE – A pedigree displayed in table or grid format. The sire is always positioned at the top of the pedigree and the dam at the bottom.

TAIL FEMALE LINE – The ‘bottom line’ of a tabulated pedigree – i.e. the dam, second dam, third dam, fourth dam etc.

TAIL MALE LINE – The ‘top line’ of a tabulated pedigree – i.e. the sire, grandsire, great-grandsire etc.


By Sally Greenwood