Effect of the Dietary Substitution of Fish Meal with Achatina fulica Meat Meal on the Growth Performance and Production Cost of African Catfish (Clarias gariepinus) Fingerlings

Fishmeal is the most preferred source of protein in aquafeeds, but it is expensive and scarce. Hence, Achatina fulica meat meal (AFM), which is much less preferred for human consumption out of three species of African giant land snails, was tested as a fishmeal substitute for Clarias gariepinus growth. Five iso-nitrogenous and iso-calorific diets were formulated, in which AFM substituted fish meal at 0% (control or Diet A), 25% (Diet B), 50% (Diet C), 75% (Diet D) and 100% (Diet E). These dietary treatments were each replicated thrice in a completely randomized design experiment, using 36-L plastic tanks in which the fish were fed daily rations corresponding to 5% of their body weight, for 8 weeks. Water quality parameters in the tanks were monitored. Proximate analyses were conducted on the fish meal, snail meal and experimental diets before the feeding trials. Cost-benefit analysis of the different diets was performed. The crude protein content of AFM (69.18%) was significantly higher than that of fish meal (55.81%). There was no significant difference (P > 0.05) in the mean weight gain, specific growth rate, feed conversion ratio, protein efficiency ratio and survival rate in fish fed Diet A and Diet B. The best protein efficiency ratio (0.77) was recorded in fish fed Diet B. Furthermore, the survival rate of fish increased with increased levels of AFM substitution. Water quality parameters were within a suitable range for tropical fish culture, indicating that the AFM did not pollute the water. The fish fed 25% AFM diet significantly (P Clarias gariepinus diets at a 25% substitution level. The aquaculture industry can thus exploit the availability of this feed resource.

Recent advances in the utilization of insects as an ingredient in aquafeeds:A review

The aquafeed industry continues to expand in response to the rapidly growing aquaculture sector.However,the identification of alternative protein sources in aquatic animal diets to replace conventional sources due to cost and sustainability issues remains a major challenge.Recently,insects have shown tremendous results as potential replacers of fishmeal in aquafeed.The present study aimed to review the utilization of insects in aquafeeds and their effects on aquatic animals’growth and feed utilization,immune response and disease resistance,and fish flesh quality and safety.While many insect species have been investigated in aquaculture,the black soldier fly(Hermetia illucens),and the mealworm(Tenebrio molitor)are the most studied and most promising insects to replace fishmeal in aquafeed.Generally,insect rearing conditions and biomass processing methods may affect the product’s nutritional composition,digestibility,shelf life and required insect inclusion level by aquatic animals.Also,insect-recommended inclusion levels for aquatic animals vary depending on the insect species used,biomass processing method,and test organism.Overall,while an appropriate inclusion level of insects in aquafeed provides several nutritional and health benefits to aquatic animals,more studies are needed to establish optimum requirements levels for different aquaculture species at different stages of development and under different culture systems.

Achievements and Prospects of Aquaculture and Aquafeed Industry in China

This article presents a comprehensive review on the achievements obtained in the past a few decades and the prospects in aquaculture and aquafeed industry in China. The total production of aquaculture in China increased from 2.38 million tons in 1978 to 36 million tons in 2008, growing 15 times in 30 years.

The application of protease in aquaculture:Prospects for enhancing the aquafeed industry

Low-fishmeal and protein-saving diets are two prominent nutritional strategies utilized to address challenges related to the scarcity and sustainability of protein sources in aquaculture.However,these diets have been associated with adverse effects on the growth performance,feed utilization,and disease resistance of aquatic animals.To mitigate these challenges,exogenous protease has been applied to enhance the quality of diets with lower protein contents or fishmeal alternatives,thereby improving the bioavailability of nutritional ingredients.Additionally,protease preparations were also used to enzymatically hydrolyze fishmeal alternatives,thus enhancing their nutritional utilization.The present review aims to consolidate recent research progress on the use of protease in aquaculture and conclude the benefits and limitations of its application,thereby providing a comprehensive understanding of the subject and identifying opportunities for future research.

Editorial special issue:Friendly nutritional strategies for sustainable aquaculture

The aquaculture sector provides the primary protein source for the global population while generating income and revenue(FAO,2020).Apart from that,aquaculturists are responsible for developing and maintaining sustainable production methods,including aquafeed production(Albrektsen et al.,2022).

Aquaculture sustainability through alternative dietary ingredients:Microalgal value-added products

Aquaculture contributes remarkably to the global economy and food security through seafood production,an important part of the global food supply chain.The success of this industry depends heavily on aquafeeds,and the nutritional composition of the feed is an important factor for the quality,productivity,and profitability of aquaculture species.The sustainability of the aquaculture industry depends on the accessibility of quality feed ingredients,such as fishmeal and fish oil.These traditional feedstuffs are under increasing significant pressure due to the rapid expansion of aquaculture for human consumption and the decline of natural fish harvest.In this review,we evaluated the development of microalgal molecules in aquaculture and expanded the use of these high-value compounds in the production of aquaculture diets.Microalgae-derived functional ingredients emerged as one of the promising alternatives for aquafeed production with positive health benefits.Several compounds found in microalgae,including carotenoids(lutein,astaxanthin,and𝛽-carotene),essential amino acids(leucine,valine,and threonine),𝛽-1-3-glucan,essential oils(docosahexaenoic acid and eicosapentaenoic acid),minerals,and vitamins,are of high nutritional value to aquaculture.

Muscle amino acid profiles of eleven species of aquacultured animals and their potential value in feed formulation

The complete quantitative essential amino acid(EAA)requirements of aquacultured animals are largely unknown except for a handful of species.This is problematic because formulation of least-cost diets for target animals demands precise knowledge of EAA requirements.One way of approximating EAA requirements is to use correlations between whole-body and/or muscle EAA profiles using essential to total EAA ratios(A/E ratios).This method requires a reference,quantified EAA requirement,usually lysine(Lys).To systematically evaluate the A/E ratio method,muscle AA profiles were measured in 10 species of teleost and whiteleg shrimp.In fish,Lys represented the dominant muscle EAA measured,ranging between 7.06 and 9.58 g/100 g protein,whereas,in shrimp,arginine(Arg)was quantified as the principal EAA.For non-EAA,glutamate(Glu)and glutamine were consistently the NEAA recorded at highest levels whereas,in shrimp,Glu+Gln was highest followed by aspartate(Asp)plus asparagine(Asn).Except for Arg,which was twice that of fish(P<0.05),whiteleg shrimp expressed similar muscle A/E profiles.Strength of relationship between muscle EAA levels and known requirements were all strongly and positively correlated for non-salmonid species.When using Lys as the reference EAA there were few semblances between measured and estimated EAA requirements.