Hog Inventory

The Hog Inventory surveys provide detailed inventory of breeding and marketing hogs and the future supply of market hogs on a quarterly basis. The United States Code, Title 7, Section 2204 authorizes the quarterly Hog Inventory survey.

Hog owners, including contractors, are the target population. The sampling universe for the hog estimation program is all hog operations with capacity to raise breeding or market hogs. A sample of hog operations from the list frame maintained by NASS is supplemented by a sample of area tracts to ensure complete coverage. All states are included in the December Hog survey while producers in the largest 29 hog producing states are surveyed during the following three quarters. Hog operations who own hogs in more than one state report inventories by state so the hogs and pigs are allocated to the proper state.


NASS publishes a quarterly Hogs and Pigs report with inventory and breeding information for each of the 16 largest hog producing states, accounting for nearly 95 percent of the total U.S. inventory. In addition, a combined total for all other states is estimated in order to publish U.S. level data. In December, NASS publishes hog information by state for all states.

About one month after each hog report, the United States and Canadian Hog Report is released. This report combines NASS hog and pig estimates with quarterly hog statistics released by Statistics Canada.

Estimates of the number of operations with hogs by herd size groups and percent of inventory on these operations are published in the Farms, Land in Farms, and Livestock Operations in February.

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Program Content

For the quarterly hog surveys, nearly 10,000 hog owners are contacted for inventory as of the first of the month for (1) sows and gilts for breeding, (2) sows and gilts expected to farrow for the next six months, (3) boars and young males used for breeding, (4) weight groups of market hogs and pigs (under 50 pounds, 50 to 119 pounds, 120 to 179 pounds, and 180 pounds and over), (5) sows and gilts that farrowed during the previous three months and the resulting pig crop whether the hog operation still owned, sold, or slaughtered the pigs, and (6) information on contractor/contractees..


Producers use this data to determine production and marketing strategies. The agricultural industry utilizes this information to assess markets and potential demand for products. USDA agencies that use this information include the Economic Research Service, Foreign Agricultural Service, Agricultural Marketing Service, and Farm Service Agency. The USDA's Office of the Chief Economist uses the data to prepare the World Agricultural Supply and Demand Estimates report. The Department of Commerce, Bureau of Economic Analysis is a major non-USDA agency that utilizes the data to prepare national and regional estimates of farm income and production.


The quarterly hog surveys are conducted in December (base quarter), March, June, and September.


The quarterly hog sample is drawn from the list of known hog owners on the NASS list frame. Owners are stratified by size of total inventory.

Information for the quarterly hog surveys is collected by mail, telephone interview, face-to-face interviews, and web-based electronic data reporting.

Special Features

A special publication, U.S. Hog Breeding Herd Structure, is periodically released. This publication includes an analysis of the hog breeding statistics.

Related Programs

Meat Animals: Production, Disposition, and Income
Livestock Slaughter
Farms, Land in Farms, and Livestock Operations

Last Modified: 11/09/2018