jpsdad, I will be interested in seeing your study on the FCR between cheaper lower protein feed and the more expensive higher protein feed. When will you be publishing the results?
Scott, I don't plan on comparing feeds but will state facts about lower protein feed and its in pond FCR. I am pretty sure I'll get better growth than you did in your trial and that after growing a month they will look better than the best of your caged fish. Heck, I fish ponds nearby with no feeding that are plumper than all of them (regardless of what you were feeding them). The only places I have ever seen BG that poor looking have been in stunted ponds. Anyways, you can rest assured that it will be a good experiment where the all the nutrients in the growing cell will be measured and reported with the results. My experimental cell will be cement lined and so feed will be the only source of nutrients for fish and other life.
This is the least of my interests, however, so different experiments are going to precede it. For now I will let Dogdoc's results speak for themselves. If after sharing my results enough would like me to do a similar experiment with high protein feed I would do it but I would want the experiment to be conducted over similar calendar period so that sunlight hours and water temps are as duplicate as possible. Wouldn't take much feed so maybe a nearby member could trade me a little in exchange for something I've grown. If I were to do the high protein experiment, I think I would do it on a protein equivalent basis. That way, the same amount of nitrogen will be introduced to the pond. How much nitrogen was assimilated will be evident at the end of trial in the weight of the fish. If there is some benefit to the higher protein feed in terms of its nutrition, then a greater proportion of the nitrogen of the feed will be assimilated in the fish of its trial. If there is no difference in assimilation then they would be essentially equivalent. If on the other hand, a counter intuitive result was evident, that is, that the lower protein feed produced greater assimilation than the higher protein feed .... well in that case I wouldn't say the lower protein feed was more nutritious. I would probably say that the result is consistent with other evidence that higher C/N ratio helps with nutrient cycling and that the carbon, the pond, and the forage organisms made the difference.
