From 1998 to 2003, world pork production grew by 11%, while Canada grew by 42%. The productivity of the sow herd in the US and Canada today is still steadily improving. This is due to several factors that include improved management, improved genetics, modern facilities, and artificial insemination. An increase in slaughter weight improves the cost of each pig produced, because the costs can be spread out over more poundage. Although the number of pigs produced in the US and Canada is increasing, the number of operations is decreasing. In the US there has been a steady increase in production contracts. Hog producers that use contracts tend to be happier with their business than those that raise their own. The current trend in dieting is low carbohydrate/high protein diet, and this is contributing to an increase in the amount of meat eaten per individual. The number of pigs being bred and farrowed is increasing steadily, and is predicted to increase into 2005 as well.