Customize the layout of the Loading Sheet by simply removing the "Brand" column and by replacing the "UOM" column with "Lot Number".
Proper operation of this feature requires System Option #53 - "Show Brand Name, Pack Size and Warehouse Location on Loading Sheet" to be enabled.
Update15 Dec 2008:
Extended this modification to include a "Total Cases" value in the page footer as well as the "Lot # Total" value. The "Lot # Total" is the numerical total of all the Lot Numbers listed on the Loading Sheet.