Nutrition of red drum, Sciaenops ocellatus L.: An additional evaluation of the effects of soya-based diets and supplemental prebiotic

Authors: ROSSI, WALDEMAR - Texas A&M University; JU, MIN - Texas A&M University; Hume, Michael; TOMASSO, JOSEPH - Auburn University; GATLIN, DELBERT - Texas A&M University

Submitted to: Aquaculture Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/25/2017
Publication Date: 4/24/2017
Publication URL: http://handle.nal.usda.gov/10113/5800443
Citation: Rossi, W., Ju, M., Hume, M.E., Tomasso, J.R., Gatlin, D.M. 2017. Nutrition of red drum, Sciaenops ocellatus L.: An additional evaluation of the effects of soya-based diets and supplemental prebiotic. Aquaculture Research. 48(10):5224-5234. https://doi.org/10.1111/are.13334.
DOI: https://doi.org/10.1111/are.13334

Interpretive Summary: We assessed the effects of a fishmeal- and two soybean-based experimental diets, either not containing or containing the feed additive GroBiotic-A, on the final growth, intestine structure, immunity, blood profiles, and intestine bacteria diversity of young red drum fish. The overall results showed that: 1) the fish were highly sensitive to soybean-based diets in the first week of feeding, and their growth was highly related to feeding time; 2) replacing 82% of fishmeal protein with soybean protein reduced growth of red drum without affecting the structure of the intestines; 3) blood cell numbers were higher in fish given the fishmeal diet than those given the two experimental diets; 4) blood plasma concentrations were not affected by the two experimental diets, while the sugar glucose was lowered and lactic acid concentrations were higher in fish given the experimental diets compared to the fishmeal diet; and 5) the diversity of intestine bacteria was affected by both the soybean diet and the diet containing the feed additive GroBiotic-A. These results reveal that substitution of high levels of soybean and soybean plus GroBiotic-A in place of fishmeal reduces red drum growth. This information is of interest to researchers and producers seeking alternative feed ingredients to improve red drum growth.

Technical Abstract: We assessed the effects of a fishmeal- (FM) and two soybean- [SOY = soybean meal (SBM) + soy protein concentrate (SPC)] based diets [with or without prebiotic (GroBiotic® -A; GBA) supplementation] on the production performance, non-specific immunity, blood parameters, and gut microbiota diversity of red drum, Sciaenops ocellatus. Three 450-g/kg crude protein (CP) and 120-g/kg lipid experimental diets were formulated. The SOY-based diets (SBM and SBM+GBA) were designed to replace 70 and 12% of FM CP in the Reference (REF) diet with SBM and SPC, respectively. GBA was supplemented in the SBM + GBA diet at 20 g/kg substituting for wheat flour. After feeding the experimental diets to triplicate groups of 25 (~ 3.4 g per fish) and 90 (~ 4.1 g per fish) red drum juveniles for 9 (Trial I) and 16 weeks (Trial II), our overall results showed that: i) the fish were highly sensitive to SOY-based diets in the first week of feeding, and their growth performance early and at the end of the feeding trials was highly correlated; ii) replacing 82% of FM CP with SOY reduced the production performance of red drum without affecting intestinal micromorphology; iii) nitroblue tetrazolium reduction was unaffected by treatment while hematocrit and plasma lysozyme activity were higher in the REF treatment; iv) plasma osmolality was unaffected by treatment, while lower glucose and higher lactate levels were observed in the SOY and SOY + GBA treatments; and v) the diversity of gut microbiota was affected by both SOY and supplemental GBA.