US swine inventories in nearly all classifications are on the decline, the US Department of Agriculture's December Hogs and Pigs report shows, say Iowa State University economists John Lawrence and Shane Ellis.

Total hog and pig numbers declined 2.2% to 66.7 million head. The inventory of breeding swine declined 2.4% to 6.1 million head, while market hog numbers were down 2.1% from last year at 60.6 million head.

In Iowa, market hog numbers were up 2.2% at 18.7 million head while sow numbers declined a percent to 1.1 million head. The decreased pig crop in the fourth quarter of 2008 and reduced imports from Canada have driven feeder pig inventories down more than 5%. With farrowing intentions down in the next six months, the retraction of the industry continues, say Lawrence and Ellis.