Size and a solid build were considered key attributes by the folks who designed our modern farm breeds. Essentially, these farming pioneers of the 18th and 19th centuries took local and ancient breeds and crossed and selectively bred them to favour particular features. This meant they chose specimens good at producing milk, examples that appeared to be hardy and healthy, and in this way began to design animals to suit particular climates, landscapes, and production aims. At its heart though there was a great deal of guesswork involved and in many cases it was a simple story of super-sizing for maximum profit. If you do pop to the cinema to watch Peter Rabbit, look at the fizzy drinks and popcorn and its the same idea at work. A bigger box of popcorn and a larger drink can be sold for more money and, broadly speaking, breeders thought the same was true for farm animals. In other words, the bigger the unit, the larger the fleece and the meatier the carcass.