no idea..
just open it and see from there id say
what it looks like, smells like should decide what to do.Ifs its properly sealed it might still be fine
At yard ours isn't bought stuff but made on the farm and we've just finished off Summer 08 haylage (big sealed bales) before we move onto this year's stuff. Due to odd tears in plastic where water/air got in some sections of a bale were off but most of it has been fine but you would need to judge what the stuff you've got looks like inside once you've opened it/smelt it to check it's OK.
Hi, would agree with others. As long as the bag is not punctured in anyway, it should have a shelf life of at least a couple of years. Open the bag and you can tell by the smell and appearance. It will have a vinigary (sp) smell if it is off. Also, a little bit of white yeast wont hurt them, but obviously dont feed if there is mould. Hope this helps.