This pic does not say if it's talking about the total or the total per unit consumed, nor does it give a measure of what the total is. The chart is unfortunately not especially helpful in a vacuum. Which is not to say you're interpreting it wrong, I just cannot tell if your conclusion there is actually valid. Or if it's post-consumer (i.e. table scraps) or industrial (i.e. animal feed that goes bad) which dramatically changes the interpretation if animal production and cereal grain waste are correlated.