just got around to checking out this board and found a subject from a few weeks ago. line breeding is used and is still being used quite extensivly in many species of critters. It just shows results much faster in animals that have quick turn arounds, rabbits, hogs ect. The USDA still has one or two experimental herds that are closed and have been since the 1920,s. I toured the Line One herd in Mont. several years ago. No outcrosses for 80 years! The speaker stated that they were just now sure enough on a few selected traits that they could guarentee the effects of selected outcrosses. There was some line-breeding suppression but the herdjust looked normal, no 7 frame animals, and they all had the right number of legs! The good part was that they could also just about guarentee no throw backs, and a 20% (I think the number is right, but it is coming from my memory) bump in selected traits thru hybird vigor in outcrosses. I think that the problem with a lot of seed stock producers is that they dont cull hard enough to make a line-breeding program stand out and pay off.