I got a 6/7 in AP Bio but I hated all of it EXCEPT the genetics chapter*

[cimorene]

When casual chatting about livestock leads to google leads to random forums where some people are like:

"OH if you're so in favor of responsible livestock breeding practices and 'not risking animals' lives with high probability of deadly pregnancies and stillbirths', then how would YOU feel if someone FORCE STERILIZED you and maybe YOUUUUU should post some pictures of YOUUUUUR family health history for us to mock, Ms. High-and-Mighty 'I Know What Genetics Is'!"

We've encountered this kind of anger twice today, once in the context of horses with genetic skeletal faults and once in the context of Dexter cattle, a heritage breed with a dangerous dwarfism trait.

It gives a whole new context to the phrase "some people shouldn't be allowed to breed", which I never thought I'd have a response to other than "kill it with fire"; but it turns out all you have to do is add "livestock, if they can't be bothered with Punnett squares*".

I honestly never thought I'd be getting enthusiastic about cattle breeds and sheeps' hooves, but I guess that's what happens when you marry into hearty farmworker stock.

*Full disclosure: as a teen (mumble 16 years ago) I loved Punnett squares. Our AP Bio teacher happened to have a teachers' edition of the text with a misprint that omitted the answers to a big section of the genetics problems, and our teacher kept getting lost trying to work them out, and several of us spent several class periods arguing with her... which I still look back on with fondness.

Comments

[spark]

I have a flock of shetlands and am always entertained when you post sheep pics =) Never heard of Punnett squares I confess. I think I have a ewe and lamb with possible congenital dwarfism -- won't be breeding from them in future, luckily that ewe is not related to the rest of my flock.

[cimorene]

Heh, I was a liiiiittle facetious there referring to the squares - that isn't really necessary for responsible behavior. I mean you already know that the biggest danger is if you breed two likely carriers together. Apparently it's a serious issue in Dexters, where breeding two "short-legged" types is highly likely to result in a stillbirth but as long as "short-legged" are bred to "long-legged" you're safe. Now that they have genetic testing, they can find out that way which animals are carriers of course, and it's possible for a short-legged cow to not have whatever gene it is.

And of course dwarfism isn't inherently dangerous (not all of it?) I think - that must depend on breed, I imagine.

[spark]

Yes, for practical matters of sheep health it mostly just comes down to, if the sheep is not a fine healthy specimen of a sheep in general, or if it has lambs that are not, then don't breed from it. Where I do spend time puzzling over recessives etc is for fleece colour genetics, which is v. complicated and interesting, you might enjoy delving into it if you haven't already.

[devon]

I lived with dog breeders who were mostly ethical, but they had this one bitch who had really perfect conformation - top show quality. Unfortunately, as she got to the age for breeding, she started having brain seizures where she'd act rabid and wild, trying to tear anyone apart. She had to be caged almost constantly because nobody could tell when the next bout would happen. It was daily, at least.

Alas, the co-owned the dog with another owner. The dog needed to be put down for real. She was a risk, and selling her puppies (big bucks!) was completely unethical. Responsible breeders would never have bred her. As it was, the other owner insisted that she not be put down, and the other owner bought out their share, and the dog went away.

I was furious about the whole thing.

[cimorene]

Oh wow, that's like BLACKOUT level rage-inducing!!! And I am not even sure who you could report it to - I don't know that the humane society is empowered to do anything? Maybe to the registering agency, whichever kennel club it is, since they would have to issue the papers? But I'm not sure if there's even any mechanism for that to be taken into account. :(

[krait]

I also loved (okay, love) Punnett squares, and used to design them for made-up fantasy or alien species of my own!

Personally, I'd just be happier if people who have assessed their own fitness for breeding and found it wanting could get voluntarily sterilised, without having to pay a fortune and/or jump through a million hoops. If getting spayed was as easy for me as it is for my dog, I'd've signed up a decade ago. Instead, it's one of those things I can only dream about in a "well, if I picked up the winning lottery ticket in the street one day..." kind of way. :/

I enjoyed reading about equine skeletal faults! Thanks for the link. :D I was a HUGE horse-crazy kid, and I remember one of the first genetic defects I learnt about in horses was Lethal White Syndrome. There's now a DNA test available so that potential parents can be checked before breeding, but for a long time coat colour was the best indicator, and "never breed frame overos" was the best guideline (sometimes ignored by uneducated or unscrupulous breeders, alas) and sometimes resulted in unpleasant surprises when unusual markings prevented correct identification of an overo.

There's a condition in merle-patterned dogs I know about, too -- Double Merle, sometimes called Lethal White Double Merle (though the dogs affected are rarely solid white, and their health problems are serious but not fatal) -- that seems to result in the kind of flame wars you found over livestock! The merle pattern is pretty, and merle pups sell well, so unscrupulous breeders will breed merle to merle in order to get guaranteed-merle puppies, despite the 25% risk of deaf-blind offspring. And, as with the overo horses, sometimes dogs can have atypical markings that mask their merle status, so breeding is assumed to be safe when it isn't.

[cimorene]

Ugh, unscrupulous breeders are just so upsetting and the refusal of legal agencies to do more about it too!

If you're interested in equine skeletal faults, there's a blog here... http://fuglyhorses.tumblr.com/ I thought Wax was reading it on Twitter, but I can't find that now so maybe I hallucinated that.

[brownbetty]

I'm not allowed to talk about dog breeding because I start frothing at the mouth.

[cimorene]

I know the feeling even though I have no actual experience of it as a community. There are also cat breeds where practices to breed for appearance and show standards put them at risk or certainty of painful or fatal conditions which are also enraging, but I haven't stumbled onto the flamewars there, either.