Traditionally sows were of the Saddleback breed. Later the Saddleback x Landrace, known as the "Blue", was used. During the recent increase in outdoor pig production, Duroc crosses have replaced the Blue. The Duroc shares the same characteristics of hardiness and good mothering ability with the Saddleback but has significantly better growth and carcase characteristics and a resistance to sunburn. Despite improved breeding and selection, the progeny from outdoor pig production systems tend to have poorer carcase quality, in terms of backfat depth, than equivalent pigs from indoor units. Reports suggest that progeny from outdoor pigs tend to have an average of 1 mm more back fat.