With all the talk about "bee diet" based upon informal "Pillsbury bake-offs"
between various commercial supplements fed to statistically insignificant
numbers of colonies, it should be noted that there is work that is dialing
in the exact ingredients and amounts in the recipe for an optimal bee diet
down to the mg/g level (one part in a thousand).
"When the trp [Tryptophan] level was 11mg/g, worker bees demonstrated better
performance in terms of
food intake, body weight, and total protein accumulation. However, 12mg/g
dietary trp promoted trp deposition in the worker bees, stimulated
hypopharyngeal gland development, enhanced the survival rate and expedited
the formation of 5-HT (5-hydroxytryptamine). The worker bees fed with 13 and
14mg/g trp had higher malondialdehyde (MDA) levels, which suggested that a
higher level of trp may be disadvantageous in maintaining worker-bee
antioxidant ability, because MDA was the end product of lipid peroxidation.
We also found that
dietary trp regulated the mRNA expression of 5-HTRs and tryptophan
hydroxylase (TPH) in a dose-dependent manner, which was related to
phototaxis, aggression, and other factors. In conclusion, dietary trp exerts
regulatory roles in the growth, development and some physiological and
biochemical properties of worker bees.Therefore, 11-12mg/g tryptophan is
optimal for A. mellifera adult worker bees."
And to stress that "more" of anything is rarely always "better":
"With increasing levels of trp, the body protein deposition in the worker
bee changed [DECREASED] in a parabolic fashion (P < 0.05) (Fig. 2)."
So, my main concerns about any pollen supplement have always been more about
the particle size, and the particle size distribution, as bees can't handle
a particle grind size that is too large, but the standard seems to center at
around 500 microns, pretty darn big at the scale of a bee. The size
distribution is pretty pathetic for most I've tested (but I've not looked in
the past 4 years).
But I can now also ask (highly annoying) questions about the even
distribution of ingredients.
This presents a very difficult task for the "chef" preparing bee feed - how
can one assure an "even grind", a "narrow distribution of particle sizes",
AND an "even distribution" of something like Tryptophan, when there is a
significant difference in results within the range of 9 mg/g to 14 mg/g?
This has nothing to do with biochemistry, and everything to do with capital
equipment investment in how one grinds non-brittle media like bee feed
ingredients. I'm not current on that- the only solution I could offer would
be the old-skool "Cryogenic" grind, where you freeze the stuff with liquid
nitrogen to make it hard enough to get the grind size you want.
Can this ever result in affordable bee feed? LN2 ain't cheap. Neither are
the toys that use it. But can any powder bee supplement meet specs at 1
part in 1000 without it? The basic physics of the problem seem... extremely
problematic.
And what ever happened to Gordy Wardell's original idea (circa 2006/2007) of
a liquid bee feed that was _manufactured_ as a liquid? Someone talked him
down to making "yet another powder".
Anyway, full text below (Demand open-access publishing! Boycott paywalled
journals!):
http://jinsectscience.oxfordjournals.org/content/15/1/161.full-text.pdf
http://tinyurl.com/hwurrez
"The Appropriate Supplementary Level of Tryptophan in the Diet of Apis
mellifera (Hymenoptera: Apidae) Worker Bees"
Fengkui, Baohua, Ge, Hongfang
J. Insect Sci. (2015) 15(1): 161; DOI: 10.1093/jisesa/iev142
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