Line Breeding: What and Why?

[CanadianRider]

There have been a few threads around lately about the breeding of a persons horse, and whether it is good etc.

Some of the replies mention line breeding.

So what is line breeding and why is it used?

 

[chev]

Linebreeding is a method of breeding (for example) a mare back to her grandsire, great grandsire or great-great grandsire to 'fix' desirable traits in a certain bloodline. The idea is that if a horse is prepotent for some desirable trait (throws that a lot) then by using him more than once in a foal's breeding, that trait is fixed in the line and srengthened.

It can work. It can also go horribly wrong. It is not without considerable risk; and the biggest risk is that while short-term it can appear to work, long-term physical weaknesses can start to appear in that line.

It's been used extensively in Welsgh breeding, and has given us a breed that's fantastically versatile, athletic, strong and talented. It's also given us a breed with a reputation for being sensitive at best; and largely unhinged at worst.

Not something I'd choose to do, but I don't have an issue with breeding from a line-bred horse with no faults using unrelated lines.

 

[fiesty_filly]

Breeders like to use line breeding because then you have a better chance of "knowing" what you are going to get. When you do a complete outcross, even within the same breed you can get some really wonky results because different lines carry different desireable traits.

My family breeds weimaraners (dogs) and we always use a distant linebreeding, such as a great great uncle, or a cousin of some sort. We pick a stud dog with desirable traits of our line (that our girl has too) and not any undesirable traits of our dog personally (such as too high set tail). The offspring from this breeding will often always have the desireable traits from the line, because it is in their genes from both sides, and if we are lucky they will get the good traits from the dam and sire.... that part all depends on luck. But overall you can better control the strong traits when line bred because those traits are well developed in both animals.

In a nutshell, line breeding is breeding for consistency.

Sorry if that is confusing, I seem to be able to describe it so much better verbally...

 

[Rips]

I don't really understand it though - its been shown and shown again that inbreeding manifests weaknesses right? In all species/breeds?
Isn't that a main problem with reastablishing rare breeds, they get inbred because theres a small gene pool and end up being weaker then the original breed was? Were welsh once endangered?

 

[Just.Jump]

Rips, inbreeding is referred to as the breeding/pairing of direct relations- brother to sister, mother to son, father to daughter. People don't do that currently, but if you look in the exceedingly common Tb or QH lines (allbreedpedigree.com), you will see that not long ago, not many people really cared to much to check just HOW related they were.

The bad effects are less so with half siblings/half relatives, but I would not do it.

As someone who wants to breed horses eventually, I wouldn't be put off of searhcing high and low for desireable traits outside of the line. I'm in NorAm, so that may every well mean searching in the smaller european countries for farm studs, but so be it. I would flat out refuse a breeding to any relations within 4 generations.

Welsh are not that bad. Technically, niether are QH or Tb horses.

You know it's bad when there is an inbreeding PERCENTAGE on a horse, specifically the friesian breed.
And yes, you need to inbreed to re-populate. We all came from maybe a handful of 'sires' ourselves, as did the thoroughbred. Just look at the cheetah as well.

 

[notpoodle]

they do it quite a bit with exmoor ponies ... often because theres not much choice in the matter (with under 1500 in the world, and as far as i know under 200 mares in the UK ....). my pony has the same stallion several times in her breeding. it reads quite worrying, but theres nothing wrong with my pony (other than sweet itch .... i know theres no hard and fast evidence for hereditary sweet itch BUT i dont think its a coincidence that so many exmoors have it compared to other breeds!)

Julia
x

 

[Kanuma]

Just jump inbreeding happens quite alot in arabs, and im convinced it is mostly to blame for the skizy stupid reputation they have. I saw quite reacently a colt born to a mare who had been put to her own sire. that was disgusting and whilst they may have gotten a sane foal from it, there are no garentees that future foals from that colt will be sane or healthy.

line breeding if done properly can be good for a breed, but too much or too close will destroy a breed

 

[chev]

Just.Jump - yes, Welsh are that bad. If you don't like line-breeding then stay away from Welsh pedigrees!

It is still very common practicve in Wales to inbreed for desirablke traits. Every single pony I own has been inbred (or line bred) to an extent. It's almost impossible to find a Welsh pony that isn;t.

do please do your research before you post.,