What are inbreeding and line breeding, and what effect do they have? My thanks to Sue Bowling for allowing me to quote extensively from her articleįirst and foremost I should emphasise that line breeding is the cornerstone of selective breeding. Selective breeding has given us cows that give the maximum amount of milk, sheep that give the maximum amount of wool, chickens that lay eggs almost every day and the most beautiful dogs in the world. There is nothing wrong with line breeding but it is like using a satellite navigation device – if it is not used intelligently you land up in Richmond, North Yorkshire when you intended to go to Richmond in London! If you are to use line breeding intelligently you have to know the basics. I hope that this short article will help. Animal Care College – caring for people caring for animals