It's time for me to switch to Layena since my girls will be 18 weeks old on Monday. So I'll be heading to the store to buy new feed on Friday. I will have about 3/4 of a 5 gallon bucket of start & grow left over though. Can I just keep this for my next batch of chicks (probably order a batch of chicks this spring) or should I go ahead and get rid of the start and grow and just buy new when I get new chicks? I'm not sure what the shelf life of the chick feed is. Thanks!