Long-Term Trends in Pigs per Litter

Key performance metrics for swine production include feed conversion, litters per sow per year, pigs per litter, and pounds of pork produced per sow per year. All of these metrics have improved dramatically over time. A recent article by Franken (2024), noted that pigs per litter reached another record in September. Improvements in production performance are critical to controlling production costs and for the industry to remain competitive in comparison to swine producers in other countries and competing meats. This article examines long-term trends in pigs per litter. Pigs per litter data for the U.S. are available from USDA-NASS on a monthly, quarterly, and annual basis. Figure 1 illustrates actual and predicted pigs per litter for the last 30 years, 1994 to 2023. A simple linear trend was used to predict pigs per litter for each year. The annual growth rate in pigs per litter was 0.107 pigs or 1.1 percent per year. This may seem small, however, over the 30-year period, this equates to an increase of 3.11 pigs per litter or an increase of approximately 37.4 percent over the 1994 to 2023 period. Production performance, measured using pigs per litter, has been particularly strong in the last few years. As evident in Figure 1, since 2015, pigs per litter have been above the trend line. This was particularly true for 2019 and 2023. Actual and predicted pigs per litter were 10.98 and 10.78 in 2019, and 11.42 and 11.21 in 2023. In other words, pigs per litter were approximately 0.2 pigs above the long-run trend for these two years.