The past half century has along with the steep decline in biodiversity in wild species also been accompanied by an incredibly rapid and often crassly intentional destruction of traditional livestock breeds and their associated cultures and adaptations.
The question I ask is do traditional genetically diverse livestock varieties have a place, or are they set to be replaced by intensively bred genetically uniform breeds?
Do you even care?
But you are talking about livestock breeds that were created by man in the first place. The only reason they exist is to fill some human need. If the need is no longer there, why should they continue existing? Anyway, we are quickly approaching the point at which artificial selection will become obsolete and any diversity we want can be created through genetic modification on demand at very little cost.
It's not really a problem. Factory farmed breeds aren't displacing all breeds. Hell, the government is even tracking who has what:
http://www.poultryimprovement.org/default.cfm (here's the chicken one)
>current extinction rates are 1,000 times higher than natural background rates of extinction and future rates are likely to be 10,000 times higher
If we want to only introduce a few adaptive traits,
but that presumes we know exactly what traits we wish to introduce and that you have maintained the source gene pool intact.
Another issue is cost effectiveness and reliability of this modification under real world conditions.