I am new to beekeeping and have followed this thread with some interest.
Searching on line it seems most DIY recipes have brewers yeast, soy flour, sugar and water in various amounts. Some add in commercial pollen supplements, low fat milk powder, egg, oil etc. Some advocate feeding in a dry form others moist.
When checking nutritional values on some of the commercial products I could not find tryptophane and many other nutrients found in honey, pollen and nectar listed on any I saw (likely only saw the tip of the ice berg) and the % of amino acids all differed and differed from the de Groot values. I presume these are based on a dry matter analysis. It appears that that resource listed only 10 essential aa for bees. Also that resource, unless I am wrong, is from 1953...not exactly recent science....not meaning it is wrong but perhaps very incomplete.
A quick search for pollen chemistry indicates there are many things in pollen that aren't listed in commercial bee supplements...not certain of source but an example is: http://www.envirobee.com/beepollen3.htm
The same data can be found for honey and there is a lot of data on plant nectars as well.
In short I remain confused as to what supplement is best nutritionally for my bees in both the short and long term.(I can't really get my head around cane sugar or equivalent being an optimum nutrition source on its own).
Is the biggest over wintering issue subclinical or clinical disease combined with housing husbandry rather than nutrition? If we feed our bees substances that do not accurately meet their physiological needs are we in the long run doing more harm than good?
Are there any firm double blind peer reviewed studies that can demonstrate that any one of the commercial and/or homemade feeding supplements is better than another or if any are better than nothing (given a hive has adequate natural reserves) or sugar alone?
It seems that there are a lot of these products purchased and fed but is it being done on anecdotal or scientific evidence?
Hopefully someone will be able to help me sort out these feeding issues (spring build up, summer dearth, fall build up, over wintering).
Thanks so much...