Archive for March 19th, 2009

I went to an alpaca genetics seminar where the speaker was asked : What is the difference between linebreeding and inbreeding? The answer: it’s called inbreeding if it doesn’t work and linebreeding if it does.  Although his answer was slightly off the cuff, I have to admit that it seems to be true as far as how the terms are used. Inbreeding has the connotation of a very close relationship (sister to brother, parent to sibling) but linebreeding seems more respectable (grandfather to granddaughter). And although both inbreeding and linebreeding for U.S. alpaca breeders seem to have a heavy negative connotation, the linebreeding prejudice seems to be waived if the resulting animal is spectacular. Ironically, linebreeding seems most evident among some of the most respected and successful breeders.  Recently in the past year or so as alpaca auction prices have seemed to start a steady decline, I’ve noticed the more frequent appearance of linebred animals in the auction catalogs. It’s just one of those things that make you stop a second and think, maybe rethink, your own stance on linebreeding.

First off, I think it must be acknowledged that to a certain extent, the reason not to linebreed may be marketing-driven in many breeding programs and I’d like to put out there for consideration  – especially for small and lesser-known breeders. It’s much harder to overcome a prejudice if you don’t have a nationally recognized program or the numbers in your breeding program to prove out a program of linebreeding. And no one wants to shrink their target market more than they need to.

On the other hand, it’s hard from a practical standpoint to draw a hard line against any linebreeding at all. After all, we have a closed registry in this country and after multiple generations,  it becomes more difficult to avoid any commonality somewhere in the pedigree on both sides.  And reasonably, what real genetic impact does an animal have three or four generations back? The answer per the above-mentioned geneticist was “None”. In fact, he felt you got neither a negative nor a positive impact when the related animals are separated by at least two generations.

So as these thoughts have been milling around in my head over time, I’ve noticed that my own position against linebreeding has ameliorated.  I’m no longer feeling the aversion over it and part of that is from my own thought processes but also from what I perceive is its overall increased acceptance in the community.

It’s also ironic that while the market seems to value the original imports over their subsequent progeny, we like to ignore any possibility that their strengths were the results of linebreeding themselves. We as breeders are always saying we strive to improve each generation but there aren’t many offspring of the “name” imports who have offspring considered to be their equal or better.  So what does that mean? Have we actually diluted the genetics that produced the desired phenotype due to our emphasis on outcrossing? Or are we just hung up on marketing? Or do the offspring just need more time and numbers to prove themselves? Or is it a reflection of the relatively young breeding expertise in this country compared to the source country?

Part of me also has to wonder if the recent devaluation in alpaca sale prices in the past year or so may have also influenced the acceptability of linebreeding. For the first time, I am hearing people talk about a meat market for alpacas and the culling of males beyond a fiber herd.  But obviously when one hand is experimenting with linebreeding, the other hand must be the hard arm of culling. So are the lower prices driving breeders to consider more aggressive breeding strategies to get better animals and making the thoughts of culling males more acceptable?

I sure would like the answers. I’d love a crystal ball, too, to tell me what would allow someone to avoid all those nasty recessive genes combining in the offspring if one ventures into linebreeding. As it has always been, everyone will decide what level they find acceptable. Right now, I’m getting my comfort level around the two generation rule. I also think that linebreeding should only be done when a breeder is so intimately familiar with a familial line that they know what dangers and benefits may result from the cross and can assess the risk responsibly. But beyond that, I haven’t drawn any conclusions. I think I would need a peek into the minds of those few breeders who do successfully linebreed.

As for inbreeding less than two generations…yuck. I’m not there yet and don’t know if I ever will be. But I’ll admit, it’s a purely instinctive and puritan reaction. The original Caligula would famously disagree.


Read Full Post »