I've always left Haylage for 3 months and Hay about the same , if when you open the haylage and it smells sweet and "heady" its a good'un , sour or musty, take it back or if you made it yourself, bad luck.Take a look at the wrap to see if there were any holes from mice or bad handling,look through the haylage for any contamination as well , lessons learnt etc etc