CREATINE SUPPLEMATION IMPROVES GROWTH AND SURVIVABILITY OF JUVENILE RED DRUM Sciaenops ocellatus RAISED IN LOW-SALINITY CONDITIONS.

Alton F. Burns* and Delbert M. Gatlin III
 Department of Wildlife and Fisheries Sciences,
Texas A&M University System,
College Station, TX 77843-2258, USA
AltonBurns@tamu.edu

 

Creatine supplementation has been shown to affect growth, immunity, and ergogenic improvements in mammals. In fish, creatine has been shown to affect sprint endurance, and osmoregulation. However, not much research has covered the effects of creatine on growth. This is likely because creatine is an organic acid not typically included in the diet. There is much interest in reducing the inclusion of fishmeal with less expensive plant protein feedstuffs. Plant proteins are devoid of creatine, and though considered dietary non-essential, supplementation may be required to sustain comparable growth, survival, and feed efficiency of some fish relative to those fed diets based on marine ingredients.

This study was performed to evaluate the effects of creatine supplementation on red drum fed a practical diet. The basal diet was formulated to contain 40% crude protein, contributed equally by menhaden fishmeal and soybean meal, 10% lipid, and 20% carbohydrate. Five experimental diets were derived from the basal diet by supplementing creatine at 0.5%, 1%, 1.5%, 2%, or 4% at the expense of cellulose, while adjusting a 50/50 blend of aspartate and glutamate to maintain the diets isonitrogenous. The experiment was conducted in 110-L glass aquaria connected as a recirculating system. Groups of 11 fingerling red drum (Wt0 8.87 ± 0.24 g) were distributed in 18 aquaria and fed the basal diet for a 1-wk conditioning period. Experimental diets were then randomly assigned to triplicate aquaria and fish were fed to apparent satiation twice daily and weighed once a week for 7 weeks. At the conclusion of the trial, fish were anesthetized and individually weighed. Liver, blood and muscle tissues were collected from three randomly selected fish per aquarium. Significant (P ≤ 0.05) improvements were observed in weight gain, feed efficiency, and survivability of fish fed the diets supplemented with creatine above 1% vs those fed the basal diet (Fig. 1). Broken-line regression analysis indicated creatine supplementation at 1.95% of diet provided optimal weight gain of red drum. Results from this study suggests red drum benefit from dietary creatine supplementation in practical diets.