Quarterly Hogs and Pigs is a NASS survey of U.S. hog and pig producers, released four times a year (typically late March, late June, late September, and late December). It is the most important single forward read on U.S. hog supply, comparable in role to Cattle on Feed for the beef market but covering a longer planning horizon because the pork production cycle stretches further forward in time than the cattle feeding cycle.
The report covers six headline numbers. Total hogs and pigs (the inventory of all hogs in the U.S. on the survey reference date), the breeding herd (sows and gilts kept for breeding), the market hog inventory (hogs being raised for slaughter, broken into weight categories), the pig crop for the prior quarter (pigs born), sows farrowed in the prior quarter, and farrowing intentions for the next two quarters. Each number tells a slightly different part of the supply story.
Why the breeding herd matters
The breeding herd is the structural supply lever. Each sow produces a litter every 142 days (gestation plus weaning plus rebreeding interval), so the breeding herd in March is what produces pigs in late spring and summer, which become market hogs in fall and winter. A 2 percent decline in the breeding herd, holding pigs-saved-per-litter constant, eventually produces a 2 percent decline in market hog inventory and slaughter. The lag is around 9 to 10 months from breeding herd change to slaughter change.
The breeding herd does not change quickly. Producers either keep more gilts (immature female pigs) for breeding or send them to slaughter. Either decision is reversible but expensive, so the breeding herd tends to drift up or down over multiple quarters rather than swinging sharply. When the breeding herd does change materially in a single report, the market reads it as a strong signal and prices in the implied supply effect over the next few months.
Why pigs saved per litter matters as much
The breeding herd is one half of the supply equation. The other half is productivity per sow, expressed as pigs saved per litter (or sometimes pigs weaned per sow per year). U.S. sow productivity has been on a long uptrend driven by genetics, nutrition, and management improvements, with pigs per litter rising from around 8 in the early 1990s to over 11 in recent years.
The combination matters: a 2 percent breeding herd decline can be fully offset by a 2 percent productivity gain, leaving total pig output unchanged. That has happened in several recent reports, and it is the reason headlines like "breeding herd at 30-year lows" sometimes coexist with stable or rising pork production. A pork buyer reading the report focuses on the implied pig crop (breeding herd times pigs per litter) more than on either number in isolation.
What the market hog inventory tells you
The market hog inventory is broken into weight categories: under 50 pounds, 50 to 119 pounds, 120 to 179 pounds, and 180 pounds and over. Each weight class moves through to slaughter on a predictable timeline. Hogs under 50 pounds reach slaughter weight in roughly 120 to 140 days. Hogs in the 180-and-over class are essentially in their last weeks before slaughter and move within 30 to 60 days.
The inventory by weight class is what gives the report its near-term value. A buyer looking at Hogs and Pigs in late March can read the 180-and-over inventory as a near-real-time slaughter forecast for April, the 120-to-179 inventory as a forecast for May and June, and the under-50 inventory as a forecast for late summer.
How buyers use the report
The market reaction to Hogs and Pigs is usually concentrated in lean hog futures and feeder pig prices, with the boxed pork market following on a lag of one to several weeks as the implied supply changes work through the slaughter calendar. A working pork buyer reads the report in two passes: a fast scan for the major surprises versus pre-report consensus, then a slower read of the weight-class breakdown and the farrowing intentions to plan for the next two quarters.
The report's revisions history matters here. Hogs and Pigs has a track record of underestimating the pig crop in some quarters and overestimating in others. Recent revisions to prior reports often appear in the new release, and a pork buyer benefits from reading the revisions as carefully as the new numbers, because the revisions describe what was missed previously and may signal continuing systematic biases.