This is long, but it gets more interesting at the end.
---
I was reading "Research Reviewed" in the latest Bee Culture and noticed
something of interest.
The article synopsized this article:
--- begin abstract ---
The effects of different levels of dietary crude protein on the
development, antioxidant enzymatic activity, and total midgut protease
activity of honey bees were investigated in the study. A total of 30
colonies of bees with sister queens were used in the test. Dietary
treatments were pure rape pollen (Control) and pollen substitutes (PS)
with crude protein (CP) levels at 15%, 20%, 25%, 30%, and 35%
(designated as PS15, PS20, PS25, PS30, and PS35), respectively. We
compared the effects of these diets on honey bees by measuring diet
consumption, bee development (egg hatch, pupation success, and pupal
weight), and the protein content of emergent adult bees, their
antioxidant status and the activity of their midgut digestive proteases.
Bees consumed significantly more (P < 0.001) natural pollen than any PS,
and bees fed PS had similar diet consumption over the entire
experimental period. However, the total protein intake was varied (P <
0.05). PS with a protein level about 30% was recognized as excellent
quality diet for maximum body weight, highest protein content and
antioxidant enzymatic activity, and PS with a protein rate about 35%
exerted the greatest effect on increasing percentage of hatch and
percentage of pupation. All these results indicate that PS appeared to
be a valuable proteinaceous food approximated to the pollen, and 30?35%
of dietary protein level was optimal to maintain the colony development.
-- end abstract ---
The Sheppard article states:
---begin excerpt ---
The control group received pollen of oilseed rape only and the other
five were fed pollen substitute diets containing 15%, 20%, 25%, 30% or
35% crude protein. The pollen substitutes contained corn meal, soybean
meal and corn gluten meal and, aside from the crude protein levels, were
considered by the researchers to have "nutrient levels.. . similar to
that of rape pollen."
_AND most importantly,_
The materials were fed in 500 gram patties (replaced as needed) that
consisted of 40% of the various dry PS or pollen materials, 50% sucrose
and 10% honey.
<snip>
The researchers also found that the antioxidant status of bees was
improved in the groups of colonies fed protein above the PS 15% level.
The two groups of bees fed patties with dietary protein levels of 30%
and 35% had significantly more midgut protease activity than the groups
fed less crude protein (including the pollen fed group). Li and
colleagues interpreted these results to suggest that the bees fed PS3O%
and PS35% not only "ate more protein but also digested and absorbed more
protein than others." In conclusion the researchers noted, "PS with a
protein level of about 30 to 35% were recognized as an excellent diet
for promoting bee
--- end excerpt ---
What is not emphasized is that the effective diets fed were NOT actually
30% and 35%, but actually, 40/100 x 30 or 35%. i.e. 12% and 14% based
on actual patty composition.
As far as I know, most patty material on th ,market is right in that
range, so this seems to be much ado about nothing.
We talk about false impressions that people get from articles in the
press. Right now, there are beekeepers thinking that they should be
seeking patties with 30 and 35% protein.
That would require a supplement with 87.5% protein! Normal ingredients
run in the 40% range.
*** In fact, it seems that they did NOT test a feed with 35% protein,
but rather _patties_ with 12 and 14% protein made from 30% and 35%
protein feeds ***
There is a difference.
Don't you think it would have been nice if someone -- the researchers,
the writer of the article or the editor -- had noticed that and
mentioned it prominently?
Or maybe I am mistaken?
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