Demonstration that Feeds Containing <1% Fishmeal Can Support Grow‐out of Large Juvenile Red Drum, Sciaenops ocellatus, and Reduce Nutrient Waste

Abstract

We conducted a 16-wk feeding trial with large juvenile red drum, Sciaenops ocellatus. Four diets were randomly assigned to six replicate tanks per treatment. Three isonitrogenous (ca. 44.5% protein) and isolipidic (ca. 14.1% lipid) extruded diets were formulated to compare a fishmeal-based diet with diets using alternative protein sources. Diet 1 contained 19.60% fishmeal and 21.42% poultry meals as primary protein sources. Two alternative diets were formulated reducing the fishmeal to 0.61% by substituting poultry meals (33.85%) and soybean protein concentrate (11.55% in Diet 2 and 11.70% in Diet 3). Diet 3 also included Allzyme Vegpro ® and Allzyme ® SSF at 0.04%. Diet 4, a natural diet consisting of chopped cigar minnows, squid, and shrimp, was used as a positive control to compare growth rates of formulated feeds to near maximum growth under these culture conditions. We found that reducing the amount of fishmeal to <1% by using alternative protein sources did not affect the growth rate, survival, or health of red drum but improved assimilation of phosphorus, reduced potential release of P to the environment, and significantly lowered the amount of feeder fish needed in feed. The control diet identified performance benchmarks for future feeds development work.

Growth and survival of juvenile red drum, Sciaenops ocellatus, acclimated to freshwater at three different stocking densities in a partial recirculation system

“…Paquotte () reported values of 1.7–1.8 in a similar system. An FCR value of 1.89 has been reported for this species in a recirculation culture system with an average salinity of 29 ppt (Denson et al, ), with an initial mean weight of 261 g and final mean weight of 580 g after culture time of 112 days. In comparison, FCR values in the current study were 2% higher in d 1 but 37% and 29% higher in d 2 and d 3 , respectively (there were no significant differences between these treatments).…”

“…In their investigation, the cultivation period lasted 547 days and included a winter season of 3 months (102 days), including the following densities: 7,500, 15,000, and 22,500 fish/ha. In comparison, in a 16‐week growout in a recirculation system, Denson et al () observed a growth rate of 2.7 g/day in salinities of 29 ± 0.9 ppt in juvenile red drum cultured from initial mean weight of approximately 261 g. In brackish groundwater (3 ppt), Forsberg et al () reported growth rates of 7.7 and 7.4%/day over 30 days with juvenile red drum (initial mean weight ca. 1 g).…”

“…This parameter was only 2% greater than the optimal limit recommended for the species. In red drum growout of large juveniles in RAS, it was found that, by applying a temperature range of 23.7–25.4°C for a period of 16 weeks (112 days), it was possible to obtain a 100% survival rate when comparing different types of diet (Denson et al, ). In pond culture, it was found that the temperatures preventing growth are those below 10°C, and the red drum species prefers temperatures above this parameter (Sandifer et al, ).…”

“…Red drum has been reared at different concentrations of total dissolved solids, with variations in the concentration of calcium (Wurts & Stickney, ) in dilute artificial seawater at 0.2 ppt with added calcium chloride (CaCl 2 ) or magnesium chloride (MgCl 2 ) (Forsberg & Neill, ). Effects of diet and environmental salinity and growth in recirculation aquaculture systems (RASs) have been reported (Craig, Neill, & Gatlin, ; Denson et al, ; Jirsa, Davis, & Arnold, ; McGoogan & Gatlin, ; Webb & Gatlin, ). Long‐term cultures of S. ocellatus have been conducted in ponds with a salinity of 28 ± 3 ppt for 18 months (Sandifer, Hopkins, Stokes, & Smiley, ) and in ponds with ranges of salinity between 8 and 42 ppt over a 340‐day period (Garces‐Botacio, ).…”

Nutritional Performance of Juvenile Red Drum (Sciaenops ocellatus) Fed Various Fish, Shrimp, and Squid Diets

“…To optimize feed costs, alternative ingredients to fishmeal, with supplements to minimize nutritional differences between the alternative ingredients and wild caught fishmeal-based feeds, need to be identified, evaluated, and validated. Soybean, corn, insect, and algae are some of the potential replacements for fishmeal that have been proven to be successful in some species [3][4][5][6][7]. However, it has been shown that these are not typically as effective for growing fish as fishmeal.…”