Breeding myths...

[CrazyMare]

Thank you. Will buy some for my box!

[AndyPandy]

Within 12-18 hours should do it Will double check and post if anyone recommends a different time frame.

[Shilasdair]

QR
I didn't worm my last foal until she was over one year old...had her worm counted regularly and never found a single egg....especially if we're talking roundworms, and threadworms which show up on faecal worm counts, I believe.
The mare hadn't had any worms for a couple of years...and yes, that foal did scour.
Also - if it is roundworm, etc - why would you use ivermectin as many of the other wormers do not have resistance yet?
I'll look up the studies...thanks for the reference.
S

[Bezique]

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I drove my mare to the stud and knocked off the follicle!

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PMSL... sorry... I may have to come back later when I have stopped laughing!...

[kumala]

Hi AP, i wonder if you could help me with a possible myth as you are the breeding guru, ET foals are not as good quality as foals that were born by their natural mother? I have seen a conversation on another forum and was hoping this wasn't true as i plan to do it possibly in a few years with my mare!

[Tia]

I was advised to worm with Ivermectin within 12 hours of giving birth; which I did and my foals didn't scour.

[arwenplusone]

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I was advised to worm with Ivermectin within 12 hours of giving birth; which I did and my foals didn't scour.

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I wasn't and so haven't treated any foals/mares in this way. But last year my filly scoured so badly we had to put her on a drip could have been a bug but I will try the Ivermectin this year and see!

Thanks AndyPandy - good post

[AndyPandy]

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...ET foals are not as good quality as foals that were born by their natural mother?

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Right, this is nature versus nurture

Genetically, an ET foal is no different to a foal from a "natural" birth. So in this respect, ET and natural foals are exactly the same.

Size wise, I think the mare's uterus is 80% responsible for the size of the foal at birth. Then the foal's genetics determine the amount of growth from that point. So theoretically, the ET foal could end up smaller or larger than a natural foal, although in practise I really don't know what the final difference is (if there is any real significant difference at all).

The argument really comes up when we talk about the foal's upbringing. A lot of ET recipients are old TBs who were too slow or too stubborn to race well. Others are unwanted shires. Generally, they are not wanted for whatever reason (generally untalented or lazy etc.). The argument goes that a grade A SJ mare will have a really hard working personality, and that will be a part of her success. So, when she has a foal, she raises that foal to be like herself... she passes on her personality (to an extent) through nurture.

Now, imagine that particular foal was flushed and transferred to a TB who was pulled from racing at 4. She's been stuck in fields, being a mum/herd animal for a couple of years. She's dosile, a bit simple, and very polite. The foal then, might become lazy, thick and naughty (because mum is too nice to tell foalie off). There-in lies your difference...

Now, I don't know whether or not these foals will have the same potential. It could quite easily work the other way, where the recipient nurtures the foal to be BETTER than if he was raised by his natural mother. No-one really knows.

There was an instance of a cloned pair of mules racing, and they hoped for a dead heat. One came 3rd, the other 7th... due to nurture and training. Who knows which had more of an influence.

In my opinion, nurture is not that strong, especially as we take the foals away from the mothers at 4-6months of age, and then they have several years of human nurturing before competing etc. At the end of the day, the genetics are the same, and genetics are the most major player in what people and animals are able to do.

Sorry if that was a little garbled

[AndyPandy]

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I was advised to worm with Ivermectin within 12 hours of giving birth; which I did and my foals didn't scour.

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THANKS TIA!

So glad someone has used ivermectin and had good results - within 12 hours it is then

[SpottedCat]

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Eggs produced by a 20 year old mare, are themselves 20 years old, as each mare is born with a all the eggs they will ever have...

I only disagree with this one. DNA suffers damage as time goes on. As egg cells are essentially the same as normal body cells bar the number of chromosomes, their DNA can also be damaged. As the mare gets older the repair mechanism cannot always repair DNA damage sufficiently so mutations can occur.
Also, as DNA goes through the cycle of damage-repair-damage-reapir, it shortens and if shortended to a significant level, genetic material is lost.

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Well, I would agree with your disagreement if oocytes were "normal" cells which underwent mitosis throughout the mares life. However, they do not.

The mare is born with a set number of primary oocytes on each ovary. The primary oocytes remain dormant until they are recruited for maturation (ootidogenesis). They are therefore not under the same aging stresses that normal cells are under (no real metabolic activity, no mitosis, no changes to the DNA). Even when they do mature, their meiosis is halted at metaphase II until fertilisation takes place.

Normal cellular aging does not effect oocytes because there is no telomere shortening, because their is no cellular reproduction. So 20 year old oocytes are not any different to 3 year old oocytes.

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I know nothing about equine breeding, but a bit about biology - are horses not subject to the same age-related genetic problems humans are? Thinking of such things as the increased risk of Down's Syndrome as women get pregnant later in life etc?

As I say, I know very little about breeding, have no intention of doing any and am just curious as I have an interest in biology.