I've wondered if feed is lacking particularly in the nutrition required to grow fish in the dimension of length. Certainly, feed grows LMB and when preferred foods like fish are unavailable. Feed grows them much faster than a diet of crustaceans and insects as Jim's work shows.
I think it would be great to understand how the improvements in the feed formulation may have allowed or encouraged changes in feeding strategy. For example, were the feed rates in terms of pounds of feed continued at the prior rate? Or did the increased concentration of beneficial nutrients allow a reduced feed rate? Or perhaps did it alter the strategy by encouraging an increase in feed rate where fish grew longer faster albeit with less obesity.
From a feed supplier perspective, I wouldn't want to increase the cost of feed if I could if for no other reason to keep it affordable for those depending on it. We understand how the feed has improved the condition of fish, it would be useful to understand whether growth rates in weight and length were improved or to what extent these may have been sacrificed to produce healthier fish.
My efforts discussed at top of thread did not test that well. I can grow LMB's at the genetic maximum using invertebrates alone, but the quantity and quality of such invertebrae forage required simply is not practical even in recreational pond settings. I can get growth in relatively large bass using just water fleas but the bass are not real good at sifting the critters requiring extremely high densities of prey. Bass can do things by changing behaviors you seldom if ever see then they have larger options like fish or even pellets that at first glance appear easier to consume.
Aquaculture Cooperative Research / Extension Lincoln University of Missouri
