The "Pound" weight unit type can't lower the precision more then 0 lb 0 oz, so you will always get the ounce note next to the pound value, and the rounding up will take it into consideration. To round the value to the closest pound, you need to express the Weight in "Pound decimal", and set its precision to 0. The template units is avaliable in BoM editor -> right click on the template in the tree view -> Template Units -> Weight (see the attached picture).
Attachment: change_precision.jpg