summarizing data from several worksheets
 

I have five worksheets, each keeping track of a different feed used by date. Each feed has several ingredients with prices that change weekly. I have set up subtotals for month. I want to gather the subtotalled information from each sheet to calculate the total amount of ingredients used for all feeds. For example, each feed contains corn. I want to know for each month how much corn I used and how much I spent on it. I would also like these subtotals by month to calculate automatically at the end of the month without having to set up each sheet to do that. Is there a way?