The size of farms had also increased substantially, with the national average rising to 1,720 hogs per operation in 2011. Dairy farming Like poultry, dairy farming in Canada is restricted under the system of supply management. In 2016 there were approximately 17,840 dairy cattle and milk production farm operators in Canada. Horticulture Horticulture crops, which includes nursery, flowers and fruits, became easier to grow with the development of plant hardiness zones. Apples, pears, plums and prunes, peaches, apricots, cherries, strawberries, raspberries, loganberries and fruit orchards are numerous and reach commercial size in the Annapolis Valley of Nova Scotia, New Brunswick, Quebec, Niagara Peninsula and Norfolk County of Ontario and Okanagan Valley of British Columbia. Hazelnuts are harvested in Eastern Canada and British Columbia. Maple syrup and maple sugar, maple butter, and maple taffy are products of Quebec along the St. Lawrence River. The main market for Canadian maple syrup and sugar is the United States. Potatoes are an abundant harvest of the Maritime provinces. Sugar beets and beet root sugar are harvested in Quebec, Ontario, Manitoba, and Alberta. Viticulture Viticulture refers to the growing of grapes for the production of wine. Ontario, and British Columbia are the two largest wine-growing regions in Canada, although grapes are also grown in other regions of Canada, including Quebec, and the Maritimes. In 2015, Canada produced 56.2 million litres of wine. Approximately 62 per cent of all wines produced that year originated from Ontario, while wineries from British Columbia constituted 33 per cent of that years wine production. Canada is the largest producer of ice wine, producing more ice wine than all other countries combined. In 2015, there were 548 wineries spread across . More than half of Canada's vineyard acreage is situated in Ontario, with 150 vineyards spread across . British Columbia holds 240 wineries, spread throughout . There are 138 wineries in Quebec, which manage of vineyards in the province. Nova Scotia holds 20 wineries, which manages of vineyards in the province. Poultry and eggs Fowl, poultry, eggs, chickens, geese, ducks and turkeys are part of a system of supply management. Under supply management, production is limited, prices are raised, and competition is severely curtailed, raising profits for farmers through artificially high prices for poultry and eggs paid by consumers. There are around 3,000 poultry farmers and 1,000 egg farmers in Canada. Aquaculture 191,259 tonnes of aquatic life were killed in Canadian