Half sibling vs by same stallion, different mare?

[Where_sMyWhite]

I get the difference between the half sibling (same dam, different sire) vs just stating who the offspring is out of and by stallion (different dam, same sire).

Curious from a breeding, selling, buying (and heck, maybe even handicapping) perspective why, it seems to me (and maybe it’s really just my personal misperception) that a bigger deal is made of offspring that are half-siblings to a horse already performing at the track vs the plethora of horses that have the same sire but different dam.

Was looking at the BH article this morning on the Fasig-Tipton sale about the timing of the F-T Saratoga sale specifically as it relates to a dark bay or brown filly by Verrazano (Hip 105) and how she is a half sister to Separationofpowers who won the Test on Saturday and didn’t go through any F-T sale.

Is it really significant when the dam is the same vs the sire?

If you were buying at this sale, would the half sister thing be a bigger deal than an opportunity to buy a Bellamy Road offspring who was the same sire as Diversify’s who won the Whitney?

Or half siblings are more “interesting” because there are going to be fewer of them??

[PeteyPie]

The difference I see is that the stallion’s quality is a known factor because he has so many offspring. It is an easy thing to measure. Also, pretty much all the stallions are great or they would be geldings. But a mare only has a few babies, so if she has had an outstanding performer, you know she can pass on that ability. Sometimes not even the best race mare will produce good race horses so if you are comparing two really good mares who are say, stakes winners, the one who has already produced winning offspring will be a better deal.

[EventerAJ]

Stallions breed up to 200 mares a year. What separates the quality of those foals is likely to be the quality of the mares. There are many stallions who can get a good horse…IF he has the best mares.

Every stallion with a significant book can get winners, even a stakes winner. But he’ll have a hundred “also rans” too, just by sheer numbers. A mare will only have a dozen or so foals, and the proven producer is more likely to get a good runner, perhaps even from a “lesser” stallion. True, there are some mares who are a one-hit-wonder, but it’s more likely than not that success runs deep in a female family…that’s why one paragraph of a sales page is for the sire, and everything else is detailed info about the produce of the first, second, third dam etc.

A mare is more interesting if she’s young, and her first runner or two does well from modest sires, as opposed to the older “proven not great” mare with 9 foals of racing age, 5 to race, 2 winners at MNR, no black type.

Buyers aren’t as interested in Bellamy Road because he’s an older, known stallion. He’s had some stakes winners, but he’s not a “hot new thing,” and he’s had time to prove himself to be a useful sire, but not in the league of Tapit, Distorted Humor, Scat Daddy, Uncle Mo, etc.

[Scribbler]

Mares imprint a lot on their foals.

And think about the huge difference between mules and hinnies.

[PeteyPie]

@Scribbler

Mares imprint a lot on their foals.

And think about the huge difference between mules and hinnies.

I would think about this but I was not aware that there is a huge difference between mules and hinnies.

Who knew? Well, you, apparently.

[LaurieB]

Pretty much what everyone has already said. A stallion has numerous chances to sire a good horse. Mares have relatively few. So a mare who has proven she can produce top flight offspring is a very valuable commodity and the half-siblings she produces to her “big horse” are justifiably sought after.

[Scribbler]

@PeteyPie

I would think about this but I was not aware that there is a huge difference between mules and hinnies.

Who knew? Well, you, apparently.

Someone accused a pony at our barn of being a hinny so I did some Googling (they might have been right). It answered a question that I’d had for years, why would you tie up mares as breeding stock for mules when using jennies and a horse stallion would be cheaper and easier?

Mules have horse bodies and donkey ears and tend to be bigger and hardier than either parent. Hinnies have donkey bodies and horse ears and tend to be donkey or pony sized. They don’t look remotely like the same genetic mix.

[Where_sMyWhite]

Thanks all and great answers Some of which I kinda knew but LaurieB’s response hit the nail on the head with respect to a mare producing a top flight offspring means she’s a valuable commodity when looking as subsequent offspring.

I knew the boys can share more of that love around with a wider based of mares which may or may not hit big (even the hot, new stallions like AP who will already start with an, or so I am assuming, elevated book)

[Palm_Beach]

It’s simple statistics. Take the top 10 stallions, who will breed 150 - 200 mares each, so the top 1,500-2,000 mares will be bred to only 10 different stallions. And some of those stallions are closely related. We can all name 10 stallions, but who can name 1,500 mares? Both mares and stallions contribute absolutely equally, but the quality of mare will vary much more than the quality of stallion, because you are looking at 2,000 different mares vs. 10 stallions. Anyone who says mares contribute more does not know basic genetics.

[Scribbler]

There are genetics and then there are epigenetics. And mares do teach foals things.

[skydy]

@Palm Beach

It’s simple statistics. Take the top 10 stallions, who will breed 150 - 200 mares each, so the top 1,500-2,000 mares will be bred to only 10 different stallions. And some of those stallions are closely related. We can all name 10 stallions, but who can name 1,500 mares? Both mares and stallions contribute absolutely equally, but the quality of mare will vary much more than the quality of stallion, because you are looking at 2,000 different mares vs. 10 stallions. Anyone who says mares contribute more does not know basic genetics.

Have you considered in your statistics the freshman stallions that are bred to many mares, that subsequently fail at producing good racehorses? Are you talking numbers covered or proven sires? If you mean proven sires, are you considering only the produce of proven mares as well?

[Palm_Beach]

@skydy

Have you considered in your statistics the freshman stallions that are bred to many mares, that subsequently fail at producing good racehorses? Are you talking numbers covered or proven sires? If you mean proven sires, are you considering only the produce of proven mares as well?

What hair are you trying to split? I’m referring to the original post.

[Scribbler]

As I understand it there’s a 50/50 chance that any gene will transmit from either father or mother. This doesn’t guarantee that every offspring is a 50/50 mix. And it doesn’t guarantee that in the genes that control for a given aptitude, the offspring will inherit the abilities we most prize.

So i think an offspring could end up with let’s say a 60/40 split in genes favoring either parent. We see this in human families where one child much more resembles the father in looks and aptitude, and the other resembles the mother.

Mother’s health, nutrition, bad habits, all influence the offspring as well. Maybe even her emotional state.

Fortunately good brood mares get good care, and aren’t out partying unaware in the first trimester

[beowulf]

@Scribbler

Mares imprint a lot on their foals.

And think about the huge difference between mules and hinnies.

I’ve thought a lot about this, because it was something I asked a long time ago in one of my biology classes, is the mode of inheritance across hybrids - and how similar species have drastically different inheritance patterns depending on the dam/sire combination (think ligers, mules, zorses).

The reason for the difference, is because horses and donkeys have different chromosome numbers - a horse has 64, while a donkey has 62. This certainly matters significantly when you consider which species is female, because the number of chromosomes you inherit from either parent depends on which species is the mother, to my knowledge.

There are a lot of things we can prove are inherited from the sire or dam - but that is generally documented in same species pairings. I am not sure if we can say with confidence if the same is true when the pairing is of two different species.

[Scribbler]

@beowulf

I’ve thought a lot about this, because it was something I asked a long time ago in one of my biology classes, is the mode of inheritance across hybrids - and how similar species have drastically different inheritance patterns depending on the dam/sire combination (think ligers, mules, zorses).

The reason for the difference, is because horses and donkeys have different chromosome numbers - a horse has 64, while a donkey has 62. This certainly matters significantly when you consider which species is female, because the number of chromosomes you inherit from either parent depends on which species is the mother, to my knowledge.

There are a lot of things we can prove are inherited from the sire or dam - but that is generally documented in same species pairings. I am not sure if we can say with confidence if the same is true when the pairing is of two different species.

Good point.

[Palm_Beach]

Any behavior that is taught to a foal by the dam can be changed by a person.

[merrygoround]

@Palm Beach

Any behavior that is taught to a foal by the dam can be changed by a person.

Yeah but, there’s a lot of genetic tendency involved. So’ I’d say “not always”. It can be modified but it will always be there.

Nature vs Nurture. They are still arguing over it.

[Scribbler]

@Palm Beach

Any behavior that is taught to a foal by the dam can be changed by a person.

On the other hand not every behavior that is learned as a foal can be eradicated. I’m thinking of bottle fed orphan colts that grow up to be dangerous horses and also sometimes have trouble integrating into herd situations as adults.

I do think that the basic education in horse social skills that a foal gets in a herd situation sets the basis for the horse being teachable by humans. That’s why mustangs in general are much easier to tame and train than you’d expect.

[Palm_Beach]

An orphan that grew up to be dangerous had poor handling.

[endlessclimb]

@Scribbler

As I understand it there’s a 50/50 chance that any gene will transmit from either father or mother. This doesn’t guarantee that every offspring is a 50/50 mix. And it doesn’t guarantee that in the genes that control for a given aptitude, the offspring will inherit the abilities we most prize.

So i think an offspring could end up with let’s say a 60/40 split in genes favoring either parent. We see this in human families where one child much more resembles the father in looks and aptitude, and the other resembles the mother.

Mother’s health, nutrition, bad habits, all influence the offspring as well. Maybe even her emotional state.

Fortunately good brood mares get good care, and aren’t out partying unaware in the first trimester

I might be stupid here, but isn’t it always a 50/50 split in terms of genes, but the expression of the genes can favor one or the other parent?

To my recollection - The mitochondria are 100% inherited from the female, so from that angle the dam has more influence.

Note: I stuck with chemistry, not biology lol. Any or all of the above can be wrong.