in 48 states, Mexico, and Canada. Today, the southern Mexico subspecies Meleagris gallopavo gallopavo is almost extinct, but in the early 16th century it was taken to Europe from Mexico by the Spanish. Its descendants later returned to America. Twentieth century commercial varieties of turkey were bred from these European descendants. The Beltsville Small White turkey was bred by the USDA at the Beltsville Agricultural Research Center in Maryland in response to consumer demand for a small (8-15 pound) turkey with more white meat and no dark feathers. It was introduced commercially in 1947 and dominated the market for nearly 20 years. The Small White was supplanted by the Broad Breasted White turkey, bred specifically for large feasts such as Thanksgiving. These turkeys can grow to over 40 pounds, but the breed must be artificially bred and suffers from health problems due to its size. It is estimated that more than 99% of the American turkeys eaten are Broad Breasted Whites. In 2006, American turkey growers were expected to raise 270 million turkeys, to be processed into five billion pounds of turkey meat valued at almost $8 billion, with one third of all turkey consumption occurring in the Thanksgiving-Christmas season (and a fifth of the overall total coming from Thanksgiving alone), and a per capita consumption of almost . Thanksgiving turkey is often stuffed with a traditional savory bread pudding and roasted. Sage is the standard herb added to the stuffing, along with chopped onions and celery. Other ingredients, such as chopped chestnuts or other tree nuts, crumbled sausage or bacon, carrots, cranberries, raisins, and/or apples, may be added to stuffing. If the mixture is cooked outside the bird, a stock is generally added to prevent it from drying out. A number of cultural and regional factors affect whether this is referred to as "stuffing" or "dressing". Turkeys may be deep-fried instead of roasted due to the shorter preparation time, but this method carries higher safety risks. The consumption of turkey on Thanksgiving is so ingrained in American culture that each year since 1947, the National Turkey Federation (and, as far back as 1873, commercial turkey farmers) has presented a live turkey to the President of the United States prior to each Thanksgiving. These turkeys were initially slaughtered and eaten for the President's Thanksgiving dinner; since 1989, the presented turkeys have typically been given a mock pardon to great fanfare