I hope not.
Pretty sure that's how they got those mass producing Holsteins. I was doing unrelated work at a retired dairy farmers place, blew me away that his calves would have sold for 6 figure prices and were shipped worldwide. Roybrook Farm was the name of the farmer and he was in his 90's would come out every morning and go visit his 70 yr old son who was in a nursing home.
http://www.thebullvine.com/breeder-profiles/roybrook-revisited/No.
Close inbreeding is an acceptable practice as long as the breeder is willing and able to drastically cull 75% of the resulting stock. According to Mendelian percentages, 50% of the results would be about average, 25% of the results would be dramatically below average, and only 25% would be exemplary. If one is striving for that exemplary 25% and willing to discard 75%, then one would have way above average results. Works for people, too, which is why there were such varying results in royal families where brother/sister matings were mandatory.
