I've run two formal trials to determine whether feeding pollen sub was of
benefit if there was a natural pollen flow going on.  In neither case was
there a measurable benefit.  This may be the case for many areas that
receive summer rain fall, and clearly in much of the East.

On the other hand, here in Calif, we received our first appreciable rain in
nearly 6 months.  There is very little late-season pollen under those
conditions, and we find a clear benefit from feeding pollen sub at
appropriate times.

In my 2013 trial of feeding when there was a pollen dearth in late summer
through January, I fed 7 lbs of pollen sub per hive.  The difference in
median colony strength at almond bloom over those fed sugar alone was
roughly 3.5 frames of bees.  Mann Lake Bulk Soft costs us about $1.05/lb,
so $7.35 cost (plus labor).  We get paid $23/frame on graded contracts, so
the benefit was $80.  Thus benefit/cost = $80/$7.35.

I'm currently running another similar trial, all colonies starting at 5
frames in early August.  At our grading on Oct 30, after feeding 6 lbs of
sub, the sugar controls graded at a median of 6 frames, the natural pollen
controls (protein matched to the pollen subs) graded at 8.5 frames of bees,
and the commercial product at 8 frames.  Since that grading, that
difference has clearly increased, but I don't yet have a formal grading.
So even at this time point, we've gained at least 2 frames of bees for a
$6.10 investment.  I expect that the return will increase by almonds, since
a larger winter cluster typically produces a much larger colony by February.

We also see a higher benefit when feeding stronger hives in September.  In
our full operation, in which we took 1000 hives to almonds last season, few
unfed colonies would have been large enough to take to almonds.  We fed fed
all our hives roughly 7.5 lbs ea in fall, and averaged 16 frames strength
in almonds, getting paid $215 for our better contracts.  Thus, under our
conditions, there is a clear benefit from feeding, with a benefit/cost of
roughly $200/$8.

I've skipped over some of the posts to this thread, so apologies if I
repeat what someone else has said.  Under my conditions, there are two
times of the year in which it is cost effective to feed sub--in January
(only if it's raining), and from Sept 1 through the end of Oct if there is
no natural pollen flow.  During those times, there is a very good return on
investment.

For those of you who don't go to almonds, such feeding may result in early
swarming.

We make all of our feeding decisions by counting backwards from when we
want colonies to reach their population peak (such as at the beginning of
the honey flow).  We feed, if necessary, to maintain the momentum of
buildup.
-- 
Randy Oliver
Grass Valley, CA
www.ScientificBeekeeping.com

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html