Older mares vs Younger mares

[Quiet Chris]

I know a guy who is looking at a few yearlings and one is out of Seattle Slew mare who was born in 1997. Someone told him to never buy a horse out of an old mare. Is there any statistical evidence younger mares are better producers or that mares tend to produce their best runners when they are young? Seems odd, but I guess there could be a biological reason for it.

Secretariat was out of an older mare and so was Sea the Stars, so I guess older mares can produce big runners, but are they just aberrations and for the most part a mares younger years are her best?

[Treve]

I know a guy who is looking at a few yearlings and one is out of Seattle Slew mare who was born in 1997. Someone told him to never buy a horse out of an old mare. Is there any statistical evidence younger mares are better producers or that mares tend to produce their best runners when they are young? Seems odd, but I guess there could be a biological reason for it.

Secretariat was out of an older mare and so was Sea the Stars, so I guess older mares can produce big runners, but are they just aberrations and for the most part a mares younger years are her best?

It's an old belief that has been debunked, but that has some truth to it as so:
The logic dictates that if the mare is older and hasn't produced anything noteworthy yet (if she has multiple foals on the ground) she's probably not a good producer. But that's less due to age and more due to sheer numbers. Course it could always be that they've failed to find the magic nick.
To my knowledge there is no biological evidence that an older mare produces less good runners, it's just that if she has many foals on the ground, of racing age and nothing to show for it, she's not likely producing a winner any time soon unless you somehow find THE nick late in her life (less likely than picking a younger mare who already has one or two winners). With a good mare who produces good foals, the quality doesn't seem to decrease with age, certainly. The only biological reason I could think of for a decrease in quality is if the mare is not healthy or has a difficult pregnancy that could affect the foal congenitally, but then she probably shouldn't breeding in the first place.

As with many old wives tales and ancient beliefs, sometimes the saying is passed down without the explanation, and therefore the thinking behind the belief gets distorted.

In both the examples you cited, Somethingroyal and Urban Sea produced winners, excellent ones even, before Secretariat and Sea the Stars respectively.
There were 10 years between Miesque's highest earner (Kingmambo) and third highest (Mingun).

I seem to recall there's an older rather well bred Seattle Slew mare who's last yearling didn't sell or sell well simply because her production record is atrocious and has never produced anything worthy of note. Dunno if this is the one I am thinking of or a different one, but with an older mare, always look at the previous nicks and her production record to date.

[TBird]

Younger mares get the best opportunities. It is a rare old(er) mare, even one who has produced well, that is bred to stallions the same caliber as the ones she started with, mostly due to the prejudice against the offspring of old mares. It is true that older mares tend to produce smaller foals which of course is another strike against them at the sales.

In my admittedly limited experience, the prejudice against older mares has not proven true. We're currently racing the 11th foal out of a very good mare. The filly was born when the mare was 18. Our filly is currently the 4th best foal out of the mare (the better ones are graded stakes and listed stakes winners) as she is "only" stakes placed but she is 3 and hasn't had that many starts yet.

When it comes to evaluating the offspring of older mares, I would look at each one individually rather than lumping them together as all the same.

[Ioya Two]

I know a guy who is looking at a few yearlings and one is out of Seattle Slew mare who was born in 1997. Someone told him to never buy a horse out of an old mare. Is there any statistical evidence younger mares are better producers or that mares tend to produce their best runners when they are young? Seems odd, but I guess there could be a biological reason for it.

Secretariat was out of an older mare and so was Sea the Stars, so I guess older mares can produce big runners, but are they just aberrations and for the most part a mares younger years are her best?

It's an old belief that has been debunked, but that has some truth to it as so:
The logic dictates that if the mare is older and hasn't produced anything noteworthy yet (if she has multiple foals on the ground) she's probably not a good producer. But that's less due to age and more due to sheer numbers. Course it could always be that they've failed to find the magic nick.
To my knowledge there is no biological evidence that an older mare produces less good runners, it's just that if she has many foals on the ground, of racing age and nothing to show for it, she's not likely producing a winner any time soon unless you somehow find THE nick late in her life (less likely than picking a younger mare who already has one or two winners). With a good mare who produces good foals, the quality doesn't seem to decrease with age, certainly. The only biological reason I could think of for a decrease in quality is if the mare is not healthy or has a difficult pregnancy that could affect the foal congenitally, but then she probably shouldn't breeding in the first place.

As with many old wives tales and ancient beliefs, sometimes the saying is passed down without the explanation, and therefore the thinking behind the belief gets distorted.

In both the examples you cited, Somethingroyal and Urban Sea produced winners, excellent ones even, before Secretariat and Sea the Stars respectively.
There were 10 years between Miesque's highest earner (Kingmambo) and third highest (Mingun).

I seem to recall there's an older rather well bred Seattle Slew mare who's last yearling didn't sell or sell well simply because her production record is atrocious and has never produced anything worthy of note. Dunno if this is the one I am thinking of or a different one, but with an older mare, always look at the previous nicks and her production record to date.

Ask Me No Secrets?

[Treve]

Ask Me No Secrets?

I think that may be exactly whom I'm thinking of. BM Sire, Secretariat right? 1998 mare this one, only one winner, by Tapit... 9-1-0-1 record. Yep I think it's her.