I just ordered 40 BPRs with the intention of maintaining a purebred flock, as well as crossing them to produce BSLs from time to time. After I placed the order I found that breeding BPRs requires breeding sports, a few different color varieties in the breed, to maintain good barring and so on. I also would like to produce RSLs using birds with a columbian type colorings. Do breeds like the Columbian Rocks and Delawares breed true? or do they also require the use of sports to maintain quality breeders?