A traditional British name for a small load, especially a small load of hay. Never standardized, the jag represented roughly 20-25 bushels (0.7-1.0 cubic meters)
Russ Rowlett (Director), How Many? A Dictionary of Units of Measurement, Center for Mathematics and Science Education University of North Carolina, USA 2005. http://www.unc.edu/~rowlett/units/dictA.html, (Unit of Meas and Covr Factors - Amer) {608}