Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 9/30/2022
Publication Date: N/A
Technical Abstract: One factor limiting the growth of the hybrid striped bass (HSB) industry is year-round spawning, which requires refined methods to rear larvae in tanks with minimal time spent on live feeds while maximizing growth and survival. The most cost-effective way to accomplish this would be using manufactured microdiets (MDs) in lieu of live feeds. Traditional tank rearing methods for this species involves up to 3-weeks of live feeds followed by weaning onto a high protein starter meal. Our lab has previously established the optimal feeding duration for live feeds to maximize growth and survival. In the current study, we looked at two methods of replacement of live feeds with: 1) direct replacement (substitute live feeds with MDs with no overlap); or 2) cofeeding replacement (live feeds then live feeds cofed with MDs before feeding MDs alone) using six different commercial or experimental MDs measured at two different developmental time points (18 days of feeding and 36 days of feeding). Significant differences in growth were found for diet, replacement strategy, and developmental time point (P < 0.0001 for every comparison). When comparing diets x replacement strategy at 18 days, the effects on growth was not clearly defined, possibly due to the short cofeeding duration. However, after 36 days all diets showed significant improvement in growth under the cofeeding strategy, but still showed inferior growth to an all-live feed strategy. This study demonstrated that when transitioning larval Morone onto manufactured feeds, cofeeding replacement maximizes growth. Further experiments to shorten the period of cofeeding while still maximizing growth will further reduce the costs of live feeds, with the ultimate goal of completely eliminating live feeds from Morone indoor larval culture.