Dear Tim:
    Bees need pollen as their source of protein.  In bee colonies which
deprived of pollen, the queen stops laying.  Simple as that.  Pollen is mixed
with honey by the bees and stored as "beebread" which they consume later
especially during winter clustering and at times when flowers are scarce.  I
have found that feeding pollen is especially helpful to colonies that are
heavily parasitized by mites.  So that is another consideration to keep in
mind.  If you have mites, it may not be a good idea to take pollen away from
your colonies.  It might be "okay" to collect pollen depending on circumstances
in your area and time of the year, BUT, bearing in mind what I indicated above.
 
Good luck with your project.
Best regards.
Dr. Rodriguez
Virginia Beach, VA