Overview
The data set for U.S. interstate livestock movements is a one-time
collection of annual shipment data compiled from USDA's National
Agricultural Statistics Service (NASS) and State animal health departments.
The data include total numbers of cattle, hogs, and sheep shipped
into States (10 years of annual data from NASS), as well as an annual
approximation of state-to-state and regional livestock flows (2001
or most recent available, from State animal health departments).
Source Report
We highly recommend reading the Interstate
Livestock Movements report for information on the economics
of livestock shipping patterns, data sources, and the methods used
to compile the data.
Total Inshipments
 Total
inshipments are the total number of livestock (cattle, hogs,
and sheep) shipped into a State for feeding or breeding and exclude
animals brought in for immediate slaughter. These data represent
the most comprehensive data set because NASS reports U.S. and State
totals for each species. Ten years of electronic data are also available.
Shipping patterns between regions and States cannot be determined
from these data because they do not provide information on origin.
For example, the map at the left illustrates total livestock inshipments
to Iowa and all other States, but does not indicate from where shipments
originate.
Livestock Flows
Regional and state-to-state
livestock movements are approximated by compiling data from State
certificates of veterinary inspection for animals destined for feeding
or breeding purposes and exclude animals for immediate slaughter.
Since source-destination data are not
available from all States, shipping patterns generated from these
data underestimate actual flows, and hence only provide a general
sense of livestock movements. For example, the map at lower left
illustrates the source of most, but not all, cattle inshipments
for the Northern Plains, because tabulated data are not available
from Nebraska. Shipments from other States to Nebraska are: 1) used
as a proxy in the lower right map and 2) included in regional flows
(lower left map). Shipment data to Nebraska are available from 17
States (thus, do not provide complete coverage).
Questions and Answers
Answers to questions such as: What are
the two sources of data used in this data product? When would I
use one source instead of the other?
|
