Hog producers in the 10 major hog producing states planned to increase their December-February farrowings by 4 percent, according to USDA's September pig crop report. This report has been a reliable indicator of the trend in total spring farrowings for the United States. This indicates a probable increase in farrowings for the entire winter-spring season, December through May.
Uhrig, J. William
Iowa Farm Science: Vol. 17
, Article 9.
Available at: https://lib.dr.iastate.edu/farmscience/vol17/iss6/9