A SWOT Analysis of the Use of Marine, Grain, Terrestrial-Animal and Novel Protein Ingredients in Aquaculture Feeds

A variety of new feed ingredients are emerging in the aquaculture feed sector. While the technology readiness of these options varies across and within the new ingredient classes, it remains important to consider them in terms of the overall feed ingredient spectrum. In this review, the use of marine, grain, terrestrial animal by-product and a range of novel (e.g., bacterial and yeast) resources being considered as potential protein feedstuffs for use in aquafeeds is explored. In comparing the nutritional attributes of each of the ingredient classes, an assessment framework is applied based on understanding the critical knowledge required to be able to accommodate any ingredient in a formulation process. To further examine each of the different ingredient classes a Strength-Weakness-Opportunity-and-Threats (SWOT) analysis is applied, to enable some consideration of what future potential may exist across the spectrum and what risks and opportunities they may bring. It is noted that all ingredients have strengths and weaknesses, and that there is no such thing as the perfect ingredient. By better appreciating the positives and negatives of each ingredient, it becomes possible to increase adaptability in responding to the various opportunities for their use in feeds

Food from the Oceans - How can more food and biomass be obtained from the oceans in a way that does not deprive future generations of their benefits?

Food from the Oceans is the first Evidence Review Report published by the SAPEA consortium. SAPEA is an integral part of the European Scientific Advice Mechanism (SAM) and this report demonstrates the outstanding commitment and knowledge of experts who were nominated by academies and learned societies. Interdisciplinarity and world-class expertise from across Europe are SAPEA’s core strengths. We assembled two international working groups for Food from the Oceans, covering both the natural sciences and the humanities/social sciences. We were delighted with SAPEA’s collaboration with the High-Level Group of Scientific Advisers (HLG), which has proved so effective in Food from the Oceans. Our Evidence Review Report informs the Scientific Opinion of the HLG. They are published together, and the aim is for them to be used by the European Commission in planning and policymaking across a range of areas. Academia Europaea performed the role of Lead Academy for the Food from the Oceans Evidence Review Report. It acted as project manager, ensuring that deadlines were met, and outputs were of the highest quality standard. By working well with academies and experts we have met all milestones leading up to and including the final deliverable, the Evidence Review Report itself. We also took a novel approach to public engagement, with encouraging results. In Food from the Oceans, we believe we have established an attractive model for future SAPEA projects. We would like to thank everyone involved in making Food from the Oceans a success and express our sincere gratitude to those who have worked hard throughout 2017

Effects of the total replacement of fish-based diet with plant-based diet on the hepatic transcriptome of two European sea bass (Dicentrarchus labrax) half-sibfamilies showing different growth rates with the plant-based diet

Background: Efforts towards utilisation of diets without fish meal (FM) or fish oil (FO) in finfish aquaculture have been being made for more than two decades. Metabolic responses to substitution of fishery products have been shown to impact growth performance and immune system of fish as well as their subsequent nutritional value, particularly in marine fish species, which exhibit low capacity for biosynthesis of long-chain poly-unsaturated fatty acids (LC-PUFA). The main objective of the present study was to analyse the effects of a plant-based diet on the hepatic transcriptome of European sea bass (Dicentrarchus labrax). Results: We report the first results obtained using a transcriptomic approach on the liver of two half-sibfamilies of the European sea bass that exhibit similar growth rates when fed a fish-based diet (FD), but significantly different growth rates when fed an all-plant diet (VD). Overall gene expression was analysed using oligo DNA microarrays (GPL9663). Statistical analysis identified 582 unique annotated genes differentially expressed between groups of fish fed the two diets, 199 genes regulated by genetic factors, and 72 genes that exhibited diet-family interactions. The expression of several genes involved in the LC-PUFA and cholesterol biosynthetic pathways was found to be up-regulated in fish fed VD, suggesting a stimulation of the lipogenic pathways. No significant diet-family interaction for the regulation of LC-PUFA biosynthesis pathways could be detected by microarray analysis. This result was in agreement with LC-PUFA profiles, which were found to be similar in the flesh of the two half-sibfamilies. In addition, the combination of our transcriptomic data with an analysis of plasmatic immune parameters revealed a stimulation of complement activity associated with an immunodeficiency in the fish fed VD, and different inflammatory status between the two half-sibfamilies. Biological processes related to protein catabolism, amino acid transaminations, RNA splicing and blood coagulation were also found to be regulated by diet, while the expression of genes involved in protein and ATP synthesis differed between the half-sibfamilies. Conclusions: Overall, the combined gene expression, compositional and biochemical studies demonstrated a large panel of metabolic and physiological effects induced by total substitution of both FM and FO in the diets of European sea bass and revealed physiological characteristics associated with the two half-sibfamilies

Energy efficiency of digestible protein, fat and carbohydrate utilisation for growth in rainbow trout and Nile tilapia

Currently, energy evaluation of fish feeds is performed on a digestible energy basis. In contrast to net energy (NE) evaluation systems, digestible energy evaluation systems do not differentiate between the different types of digested nutrients regarding their potential for growth. The aim was to develop an NE evaluation for fish by estimating the energy efficiency of digestible nutrients (protein, fat and carbohydrates) and to assess whether these efficiencies differed between Nile tilapia and rainbow trout. Two data sets were constructed. The tilapia and rainbow data set contained, respectively, eight and nine experiments in which the digestibility of protein, fat and energy and the complete energy balances for twenty-three and forty-five diets was measured. The digestible protein (dCP), digestible fat (dFat) and digestible carbohydrate intakes (dCarb) were calculated. By multiple regression analysis, retained energy (RE) was related to dCP, dFat and dCarb. In tilapia, all digestible nutrients were linearly related to RE (P2 for trout (NE in kJ/(kg0·8×d); dCP, dFat and dCarb in g/(kg0·8×d)). In tilapia, the energetic efficiency of dCP, dFat and dCarb was 49, 91 and 66 %, respectively, showing large similarity with pigs. Tilapia and trout had similar energy efficiencies of dCP (49 v. 57 %) and dFat (91 v. 84 %), but differed regarding dCarb.</p

Influence of dietary astaxanthin on the hepatic oxidative stress response caused by episodic hyperoxia in rainbow trout

A 13-week feeding trial was carried out with juvenile rainbow trout to test two diets: a control diet without astaxanthin (AX) supplementation (CTRL diet), and a diet supplemented with 100 mg/kg of synthetic AX (ASTA diet). During the last week of the feeding trial, fish were exposed to episodic hyperoxia challenge for 8 consecutive hours per day. Episodic hyperoxia induced physiological stress responses characterized by a significant increase in plasma cortisol and hepatic glycogen and a decrease in plasma glucose levels. The decrease of plasma glucose and the increase of hepatic glycogen content due to episodic hyperoxia were emphasized with the ASTA diet. Hyperoxia led to an increase in thiobarbituric acid-reactive substances in the muscle, diminished by dietary AX supplementation in both liver and muscle. Muscle and liver AX were increased and decreased respectively after 7-day episodic hyperoxia, leading to an increase in flesh redness. This augment of muscle AX could not be attributed to AX mobilization, since plasma AX was not affected by hyperoxia. Moreover, hyperoxia decreased most of antioxidant enzyme activities in liver, whereas dietary AX supplementation specifically increased glutathione reductase activity. A higher mRNA level of hepatic glutathione reductase, thioredoxin reductase, and glutamate-cysteine ligase in trout fed the ASTA diet suggests the role of AX in glutathione and thioredoxin recycling and in de novo glutathione synthesis. Indeed, dietary AX supplementation improved the ratio between reduced and oxidized glutathione (GSH/GSSG) in liver. In addition, the ASTA diet up-regulated glucokinase and glucose-6-phosphate dehydrogenase mRNA level in the liver, signaling that dietary AX supplementation may also stimulate the oxidative phase of the pentose phosphate pathway that produces NADPH, which provides reducing power that counteracts oxidative stress. The present results provide a broader understanding of the mechanisms by which dietary AX is involved in the reduction of oxidative statu