Question- when someone advertises their birds as being from a specific line ie..Greenfire farm are the chicken/eggs that they are selling directly out of a Greefire bird or do they have Greenfire somewhere in the lineage of the birds/eggs?
		
		
	 
 
	
		
	
	
		
		
			I guess what I'm asking is if I bought eggs from catdance silkies or Greenfire farm if I kept their birds separate and did not breed to my birds they would still be considered their line. But, if I breed their birds to mine, then I would no longer say they were catdance or Greenfire line?
		
		
	 
I'm going to put in my two cents and then be quiet, 

 LOL  A line is someone's breeder birds;  the ones they specifically choose to place into their breeding program.  There have to be descendents and progenitors in order to be a 'line'.  There are all sorts of differing opinions on what makes a line, a line...
nobody is necessary right and nobody is necessarily wrong - just different.
 
In my opinion - a line stops belonging to Person A the moment they sell those birds to Person B.  Even if they are a trio, and kept separated from all other flock members, they are still going to have chicks out of a clutch that hatch out, that Person A may have considered a cull for one reason or another.  Because of this, that isn't the original line, because there would be no descendants or future progenitors brought forth by the original breeder.  Thus, it becomes Person B's line, because *
they* are choosing which chicks are culls and which are going to be in their breeding pens - Person A has no say so in which chicks are culled and which are kept, so really it is no longer their line because they are not picking their progenitors.
 
Also, environment, feed & nutrition, free ranging versus coop/run all effect a "line".  One chicken from Person A may be the epitome of perfection on their farm...but once it transfers to Person B, they may not keep them in any sunlight, or feed them anything of nutritional value, or treat them when they have lice, mites or other parasites, or treat them when they are otherwise ill..or let them live in filth - but still let them breed constantly. Thus...that bird that was in Person A's line (in my opinion) is not the same bird at all, and will not produce the same eggs nor will it produce the same chicks.   Chicks health is very much dependent upon the health and composition of the hen and the roo that created it.   If those birds used to be show birds and are now an absolute mess because of Person B - they will not be the same composition as they once were and thus their offspring will not be the same line.
 
Like I said..just my two cents.  My shortened version is "my line starts when there's a package of chickens with a shipping label on it delivered to my door".  
 
[
Edited to add]:  Once I start breeding and selling Seramas I plan on advertising them as "My Name's line, originating from the stock of so-and-so."
 
(
but I 100% respect the opinions of those who disagree)