Optimizing fish meal-free commercial diets for Nile tilapia, Oreochromis niloticus

Abstract

A feeding trial was conducted in a closed recirculating aquaculture system with Nile tilapia Oreochromis niloticus juveniles (mean weight, 6.81 g) to examine the response to a practical diet containing protein primarily from menhaden fish meal (FM) and soybean meal (SBM) (control, Diet 1) or to diets with decreasing ratios of PBM to SBM (Diets 2-7; dose-response) as a total replacement for digestible protein from FM, and the efficacy of 1% supplemental taurine (Tau) at the highest level of plant protein inclusion by removing Tau (Diet 8). To the extent possible, the replacement diets were formulated using currently published amino acid availabilities for the ingredients of interest in order to estimate and supplement the first two limiting amino acids (Met and Lys) to match levels in the FM control diet. The test diets were formulated to contain 35% digestible protein. Fish were fed three times daily all they would consume in 30 min. All performance measures were quadratic with respect to PBM: SBM ratio in the diet. The highest weight gain, lowest average daily feed intake, lowest feed conversion, 52 and greatest specific growth rate coincided with a dietary PBM:SBM ratio of 1.22 to 1.35 53 suggesting the best tilapia performance in the current trial was achieved with replacement formula D3 that contained approximately 20% SBM, 30% PBM, and supplemental Lys, Met, and 55 Tau. However, all growth performance measures were significantly linear and decreased with respect to increasing distance from the ideal protein amino acid profile for tilapia. Positive 57 effects of taurine supplementation at the highest level of dietary plant protein inclusion were 58 not observed and may have been overwhelmed by imbalances in other amino acids in the test 59 diets. The current results provide evidence that total deviation from the ideal protein profile in 60 tilapia is an important consideration for diet formulation when combinations of diet ingredients 3 of 39 are used. Hence, the essential amino acid content of a fish meal control diet may be an inadequate target for optimizing fish meal replacement diets for tilapia; whereas the whole body or muscle amino acid pattern may be a more useful formulation target. Finally, while the database of ingredients that have been evaluated in tilapia is growing, the industry will benefit 65 from more efficient diets as long-term averages of amino acid composition and digestibility accrue for a variety of traditional and novel ingredients.

Effects of feed ingredients on nutrient digestibility, nitrogen/energy balance and morphology changes in the intestine of Nile tilapia ( Oreochromis niloticus )

“…In the case of tilapia, a wealth of alternative protein sources is available and in use. For some of these ingredients, the apparent nutrient digestibility has been reported already, for example, cottonseed meal and sunflower meal (SFM; Aanyu, Ondhoro, Ganda, Kato, & Basiita, ; El‐Saidy & Gaber, ), feather meal (Guimarães, Pezzato, & Barros, ), dried distillers grains with solubles (DDGS) (Schaeffer, Brown, Rosentrater, & Muthukumarappan, ), rice bran (RB) (Guimarães, Pezzato, Barros, & Tachibana, ), rapeseed (Borgeson, Racz, Wilkie, White, & Drew, ) and soybean meal (SBM) (Koch et al, ; Lin & Luo, ; Vidal et al, ). The substitution of fish meal coincides with an increased variability in dietary nutrient/ingredient composition.…”

The effect of replacement of fish meal with Amino Acids and Optimized Protein Levels in the diet of the Nile Tilapia Oreochromis niloticus

“…However, more investigations are required to evaluate the performance of different combinations of alternative constituents to prepare a balanced tilapia diets. Koch et al (2016) demonstrated that the available economical feeds for O. niloticus entail nutrient reduction or are unbalanced, such that the decreased feed utilization is likely to release unutilized protein, carbohydrates, and other constituents into, and cause eutrophication of, adjoining water reserviors (Montanhini Neto and Ostrensky, 2015). Meanwhile, Webster et al (1999) reported that compounding animal and plant protein sources with additional amino acid profiles may enhance the possibility of nutrient inadequacy that could adversely affect fish growth.…”

Digestibility and pricing of Chlorella sorokiniana meal for use in tilapia feeds

“…Future evaluations of CSM as alternative protein source to FM in tilapia nutrition should take into account that adding FM to tilapia feed formulations is rather low -ordinarily circa 2 -5 % (Chiu et al, 2013). As a matter of fact, the use of FM in tilapia diets is possibly unnecessary (Koch et al, 2016). Consequently, it is logical to use CSM as replacement to SBM as protein source, or as it is a good source of digestible lysine, CSM could replace costly synthetic lysine sources.…”