Comments on: Genetic variation & cattle

By: Eric Gagen

Eric Gagen — Fri, 01 Feb 2008 08:01:26 +0000

I also thought along the lines of pconroy. If the Ankole are good beef cattle they should be improved following those lines. I live in South Louisiana and the most popular beef cattle breed here is the Brangus – a cross between Angus (tasty) and Brahma (good resistance to heat and tropical diseases) Perhaps the Ankole is another candidate for introducing heat and tropical disease resistance to standard beef cattle.

The real problem in Uganda isn’t that there is cross breeding occuring, but that most of it is being done helter skelter rather than with any particular objectives in mind. It’s likely that it will produce no positive results, or at least not the positive results that could be produced by a directed breeding program.

By: pconroy

pconroy — Thu, 31 Jan 2008 12:15:47 +0000

I read the whole article, and came away with a different conclusion that some of you.

Ankole had been kept for both meat and milk production, making them neither great at either. Holsteins are specialist milk producers, so compared to the Ankole, they will always beat them. Ankole however supposedly produce a rather good tasting steak. So with a little more selective Ankole breeding, they may be turned into a meat producing breed to possibly rival Aberdeen Angus, for prime quality.

Obviously it would be useful if the Holsteins could pick up some drought and tropical disease resistance alleles from the Ankole. But once these have been located, they can be transferred to the Holsteins later...

So there you have it, a best of breed solution.

By: Eric Gagen

Eric Gagen — Thu, 31 Jan 2008 11:16:07 +0000

I think if a very large # of Holsteins is suddenly introduced to a smaller population of Ankole, or the Holsteins are selectively bred more aggressively than the Ankole that there are three risks:

In a fairly short period of time nobody will remember what the good characterstics of the Ankole were - even if the genetics are still hidden in Holstein looking cows, nobody will look for them.

It's possible for the potentially positive Ankole characteristics to be the result of a group of genes working in concert - which would be broken apart by crossbreeding

It's possible that the beneficial genes get so widely dispersed among a large # of Holstein genes that they cannot reasonably be found even if people start to look for them later on.

By: razib

razib — Mon, 28 Jan 2008 01:34:28 +0000

right, but it’s not the cross-breeding per se that’s the problem. it’s the reduction in effective size and/or selection of the F1…Fn….

By: gc

gc — Mon, 28 Jan 2008 01:15:52 +0000

genetics is discrete, and that information isn't destroyed through cross-breeding.

Hmmm? Cross breeding of the sort described in the article will drive the frequency of local alleles down and of foreign alleles up. Many infrequent local alleles will quickly be driven to a frequency of zero, because of the strong artificial selection pressure against their propagation. The most common alleles will stick around for sometime, but it's not true that "information isn't destroyed".

By: AS

AS — Sun, 27 Jan 2008 11:04:40 +0000

Check out the Nazi yaks

By: Caledonian

Caledonian — Sun, 27 Jan 2008 07:17:44 +0000

If we have access to the original strains, we can later choose to make whatever crosses and hybridizations we please.

Once we've made the crosses, if we didn't preserve the parents, there's really no way to retrieve the originals without genetic engineering far beyond our current technology and a lot of guesswork.

Genes are discrete, but phenotypes are composed of the interaction of so many discrete elements that they often look and act continuous.

(sigh) This is so much simpler with potato breeding...

By: David Boxenhorn

David Boxenhorn — Sun, 27 Jan 2008 03:03:27 +0000

Here's the link.

By: razib

razib — Sun, 27 Jan 2008 00:34:06 +0000

Are either the Bahima or Bairu people lactose intolerant? From the descriptions it seemed the Bahima were Tutsi and the Bairu Bantu, but I'm not sure.

i think you're assessment is right. wikipedia calls the ankole 'watusi' cattle. as for lactase persistence (the PC-genetic term we prefer! ;-) it seems like it varies the way you assume. there is an allusion to this possibility in the text, but as you said, they didn't push it very far.

By: hj

hj — Sun, 27 Jan 2008 00:21:47 +0000

Are either the Bahima or Bairu people lactose intolerant? From the descriptions it seemed the Bahima were Tutsi and the Bairu Bantu, but I’m not sure.

If so, it is possible the Bahima may be overly attached to their status as lactose-tolerant Tutsis amongst lactose-intolerant Bantu populations and the ankole cattle that have conferred this nutritional advantage. The rise of dairy cattle as an export industry allows the potentially lactose-intolerant Bairu to profit off Holstein dairy cattle in a way that threatens the previous genetic-driven division of labor between the two populations.

I thought this article as especially interesting if viewed through a human genetics lens of lactose tolerance. How genetic variability between Bahima and Bairu produced the Ugandan social structure, and perhaps how the differing traits have slowly evinced themselves in marriage patterns and their creation myths:

http://www.ugandatravelguide.com/ankole-culture.html

The NYT article fails to talk about the cheapest method of saving the ankole. Allow a small feral population to breed like the Texas longhorns or the feral Dromedaries of Australia. Both populations have become valuable gene banks for the American cattle industry and Middle Eastern camel trade at practically no cost.