In 1966, the French stud book was changed to include draft types from other areas of France that were closely related to the Percheron – including the horses of Berrichon, Nivernais, Marne, Augeron, Bourbonnais, Loire and Saône-et-Loire.[1] French Percherons were also hit hard by the advent of mechanization, and between 1970 and 1990 focus was placed on breeding horses of greater mass for the meat market. The largest and heaviest stallions were selected for breeding.[2][27] Beginning at the 1989 World Percheron Congress, French breeders realized that they needed a lighter breed for tourism, export to Japan for draft work, and other markets.[26][28] In 1993, a trend of importing American stallions to France was started with the black stallion Silver Shadows Sheik.[29] This stallion and others were used to create a more elegant, smaller and sleeker look in the French Percheron, while still retaining the traditional bone and foot structure. All the imported stallions were black, reviving the popularity of black Percherons in France.[26] French breeders continue to import American-bred Percheron stallions in order to produce lighter foals, moving away from the heavier meat-type horses of the late 20th century.[30] Also in 1993, the Société Hippique Percheronne anticipated the increasing tourist and exportation markets by prohibiting docking, which was not prohibited for other draft breeds until 1996.[31] This was partly at the request of the Germans,[32] and partly due to the influence of magazines such as Cheval.[33]