thawed milk...need clarity

[Lizzybee]

In UK guidance on storing breastmilk is 5 days in fridge, 2-3 weeks in freezer compartment and 6 months in a freezer.
If I thaw it it fridge why is it only good for 24 hours and not the 5 days like it would have been if I'd just left it in fridge? I always freeze as soon as expressed.

 

[sheldonsmommy]

I think it's because some of the good bug-fighting antibodies die when it's frozen, so it can go bad much faster.