Broodmare Sire (Damsire) Explained
The broodmare sire, also called the damsire, is the sire of a horse's dam. He sits in the second generation of the pedigree, on the bottom half, and he is analysed separately from the sire in almost all serious pedigree work.
Where he sits
Take any horse. Its sire is the top half of the first generation, its dam the bottom half. Go back one further, and the dam's own sire is the broodmare sire.
In a sales catalogue, he appears immediately after the dam's name, which is why you will see a horse described as "by Stallion A out of Mare B, by Stallion C". Stallion C is the broodmare sire. In shorthand, you will see the same relationship written as a cross: Stallion A over Stallion C mares.
Why he is treated separately
A broodmare sire contributes roughly a quarter of the genetic material, the same as the paternal grandsire on the top side. He is singled out for two reasons.
First, tradition and evidence both suggest the damsire's contribution shows up in particular characteristics. Breeders have long associated the broodmare sire with soundness, temperament and structural balance, the qualities that determine whether a horse trains on and stays sound rather than how fast it is at its peak. Whether that association is fully explained by genetics or partly by observation habit, it is deeply embedded in how the industry reads a page.
Second, and more practically, the sire and broodmare sire together form the cross that nicking is built on. Almost every commercial assessment of a mating starts with this pairing, so it has become the most heavily studied relationship in the pedigree.
Good sires are not always good broodmare sires
This is the point that surprises people new to pedigree, and it is one of the more useful things to understand.
Some stallions produce excellent racehorses, but their daughters do not produce at the same level. Others are moderate on the track as sires, yet their daughters become outstanding producers, and the stallion's lasting influence on the breed comes almost entirely through the female side.
The reason is that being a successful sire and being a successful broodmare sire are different tests. A sire is judged on what he transmits directly to his progeny. A broodmare sire is judged on what his daughters transmit, in combination with whatever stallions they are sent to. A stallion whose daughters are physically well made, sound and consistent can be a superb broodmare sire even if he never produced a top-class runner himself.
This is why a mare's page should be read with the damsire's record as a broodmare sire in mind, not just his record as a sire.
The damsire in a mating decision
When assessing a proposed mating, the broodmare sire does several jobs at once.
- He defines the cross. Sire over damsire is the pairing most nick ratings assess.
- He is a likely duplication point. Because he sits close up in the pedigree, any appearance of the same horse or his close relatives on the sire side creates meaningful inbreeding or linebreeding, often at 3x2 or 3x3.
- He shapes aptitude. A speed-oriented damsire under a staying sire produces a different profile to the reverse, and this is one of the main levers breeders use to adjust the likely distance range of a foal.
- He carries surface tendency. A damsire whose progeny excelled on one surface transmits that leaning to his daughters' foals.
How G1 Goldmine uses the damsire
The broodmare sire is a first-class filter throughout the platform rather than an incidental field. You can filter the stallion roster by sire and by dam sire when searching for a match, and the dashboard lets you save favourite damsires so that crosses you rate are easy to return to.
In pedigree search, the damsire is one of the ancestors you can specify directly, including targeting the exact generation his influence sits in, so you can find every stakes winner carrying a particular sire over damsire combination and examine what those horses actually did.
The Impact Profile treats the sire over damsire cross as one of the key crosses it assesses, but importantly it is one of 20 rather than the whole analysis. That keeps the damsire in proportion: influential, closely watched, and still only part of the pedigree.