Showing papers on "Commercial fish feed published in 2016"
TL;DR: The fatty acid composition of over 3,000 Scottish Atlantic salmon farmed between 2006 and 2015 is compared to find that terrestrial fatty acids have significantly increased alongside a decrease in EPA and DHA levels, and the nutritional value of the final product is compromised.
Abstract: As the global population and its demand for seafood increases more of our fish will come from aquaculture. Farmed Atlantic salmon are a global commodity and, as an oily fish, contain a rich source of the health promoting long-chain omega-3 fatty acids, eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. Replacing the traditional finite marine ingredients, fishmeal and fish oil, in farmed salmon diets with sustainable alternatives of terrestrial origin, devoid of EPA and DHA, presents a significant challenge for the aquaculture industry. By comparing the fatty acid composition of over 3,000 Scottish Atlantic salmon farmed between 2006 and 2015, we find that terrestrial fatty acids have significantly increased alongside a decrease in EPA and DHA levels. Consequently, the nutritional value of the final product is compromised requiring double portion sizes, as compared to 2006, in order to satisfy recommended EPA + DHA intake levels endorsed by health advisory organisations. Nevertheless, farmed Scottish salmon still delivers more EPA + DHA than most other fish species and all terrestrial livestock. Our findings highlight the global shortfall of EPA and DHA and the implications this has for the human consumer and examines the potential of microalgae and genetically modified crops as future sources of these important fatty acids.
339 citations
TL;DR: The results provide data on how fish diet influences the RAS environment and corroborate previous findings that diet has a clear influence on the microbiome structure of the salmon intestine, particularly within the order Lactobacillales (lactic acid bacteria).
Abstract: Reliance on fishmeal as a primary protein source is among the chief economic and environmental concerns in aquaculture today. Fishmeal-based feeds often require harvest from wild fish stocks, placing pressure on natural ecosystems and causing price instability. Alternative diet formulations without the use of fishmeal provide a potential solution to this challenge. Although the impact of alternative diets on fish performance, intestinal inflammation, palatability, and gut microbiota has been a topic of recent interest, less is known about how alternative feeds impact the aquaculture environment as a whole. The recent focus on recirculating aquaculture systems (RAS) and the closed-containment approach to raising food fish highlights the need to maintain stable environmental and microbiological conditions within a farm environment. Microbial stability in RAS biofilters is particularly important, given its role in nutrient processing and water quality in these closed systems. If and how the impacts of alternative feeds on microbial communities in fish translate into changes to the biofilters are not known. We tested the influence of a fishmeal-free diet on the microbial communities in RAS water, biofilters, and salmon microbiomes using high-throughput 16S rRNA gene V6 hypervariable region amplicon sequencing. We grew Atlantic salmon (Salmo salar) to market size in six replicate RAS tanks, three with traditional fishmeal diets and three with alternative-protein, fishmeal-free diets. We sampled intestines and gills from market-ready adult fish, water, and biofilter medium in each corresponding RAS unit. Our results provide data on how fish diet influences the RAS environment and corroborate previous findings that diet has a clear influence on the microbiome structure of the salmon intestine, particularly within the order Lactobacillales (lactic acid bacteria). We conclude that the strong stability of taxa likely involved in water quality processing regardless of diet (e.g., Nitrospira) may further alleviate concerns regarding the use of alternative feeds in RAS operations. IMPORTANCE The growth of the aquaculture industry has outpaced terrestrial livestock production and wild-capture fisheries for over 2 decades, currently producing nearly 50% of all seafood consumed globally. As wild-capture fisheries continue to decline, aquaculture9s role in food production will grow, and it will produce an estimated 62% of all seafood consumed in 2020. A significant environmental concern of the industry is the reliance on fishmeal as a primary feed ingredient, as its production still requires harvest from wild fisheries. Our study adds to the growing body of literature on the feasibility of alternative, fishmeal-free diets. Specifically, we asked how fishmeal-free diets influence microbial communities in recirculating salmon farms. Unlike previous studies, we extended our investigation beyond the microbiome of the fish itself and asked how alterative diets influence microbial communities in water and critical biofilter habitats. We found no evidence for adverse effects of alternative diets on any microbial habitat within the farm.
112 citations
TL;DR: The results indicate that an inclusion up to 500 g kg−1 of TM in the diet did not affect feed intake, in vitro protein digestibility, muscle amino acid composition or biometric indexes, however, their inclusion reduced growth performance and affected the muscle fatty acid profile.
Abstract: Fishmeal (FM) and soy meal (SM) are the most common protein sources used in fish feed, but they are associated with environmental, economic or production problems. Insects could be an interesting alternative source of protein. This work investigates the nutritive value of Tenebrio molitor meal (TM) and the effect of total replacement of SM by TM (TM/FM diet) or partial replacement of FM by TM (TM/FM/SM diet) versus a diet based in SM and FM (FM/SM diet) for tilapia. We studied the chitin content in TM, the in vitro protein digestibility, protease activity, oxidative stress and antioxidant defences, growth performance and nutrient utilization. The results indicate that an inclusion up to 500 g kg−1 of TM in the diet did not affect feed intake, in vitro protein digestibility, muscle amino acid composition or biometric indexes. However, their inclusion reduced growth performance and affected the muscle fatty acid profile. The lowest values for protease activity, elevated FRAP in digestive tracts and ROS level in muscle and higher SOD activity were observed in fish fed with SM/FM diet. The use of TM requires better understanding of the role of chitin in digestion and the study of toxins that might affect fish growth.
105 citations
TL;DR: Histological and gene expression data suggest that butyrate and taurine could have a role in normalizing the intestinal abnormalities caused by the SBM, but the underling mechanisms of action seem different.
Abstract: Due to the paucity of oceanic resources utilized in the preparation of diets for cultured fish, commercial feed producers have been trying to replace fishmeal (FM) using alternative protein sources such as vegetable protein meals (VMs). One of the main drawbacks of using VMs in fish feed is related to the presence of a variety of anti-nutritional factors, which could trigger an inflammation process in the distal intestine. This reduces the capacity of the enterocytes to absorb nutrients leading to reduced fish growth performances. We evaluated the mitigating effects of butyrate and taurine used as feed additives on the morphological abnormalities caused by a soybean meal (SBM)-based diet in the distal intestine of sea bass (Dicentrarchus labrax). We used three experimental diets, containing the same low percentage of FM and high percentage of SBM; two diets were supplemented with either 0.2% sodium butyrate or taurine. Histological changes in the intestine of fish were determined by light and transmission electron microscopy. Infiltration of CD45+ leucocytes in the lamina propria and in the submucosa was assessed by immunohistochemistry. We also quantified by One-Step Taqman® real-time RT-PCR the messenger RNA (mRNA) abundance of a panel of genes involved in the intestinal mucosa inflammatory response such as TNFα (tumor necrosis factor alpha) and interleukins: IL-8, IL-1β, IL-10, and IL-6. Fish that received for 2 months the diet with 30% soy protein (16.7% SBM and 12.8% full-fat soy) developed an inflammation in the distal intestine, as confirmed by histological and immunohistochemistry data. The expression of target genes in the intestine was deeply influenced by the type of fish diet. Fish fed with taurine-supplemented diet displayed the lowest number of mRNA copies of IL-1β, IL-8, and IL-10 genes in comparison to fish fed with control or butyrate-supplemented diets. Dietary butyrate caused an upregulation of the TNFα gene transcription. Among the quantified interleukins, IL-6 was the only one to be not influenced by the diet. Histological and gene expression data suggest that butyrate and taurine could have a role in normalizing the intestinal abnormalities caused by the SBM, but the underling mechanisms of action seem different.
80 citations
TL;DR: Results of this study indicate that FSM can be used successfully as a replacement for FM at levels up to 20% in diets for juvenile rockfish while at least 40% of dietary FM protein can be replaced by FSM without causing any adverse effect on grower rockfish performance.
79 citations
TL;DR: Cricket meal could be an alternative to fishmeal as a protein source in the African catfish diet, when compared to 100 % FM.
Abstract: This study was conducted to investigate the growth performance, biomarkers of oxidative stress, catalase (CAT), superoxide dismutase (SOD), and glutathione S-transferase (GST) as well as the haematological response of African catfish after being fed with fish feed containing different levels of cricket meal. The juvenile fish were assigned to three different treatments with isonitrogenous (35 %) and isoenergetic (19 kJ g−1) diets containing 100 % cricket meal (100 % CM), 75 % cricket meal (75 % CM), and 100 % fishmeal (100 % FM) as control groups for 7 weeks. The results indicated that a diet containing 100 % CM and 75 % CM improved growth performance in terms of body weight gain and specific growth rate, when compared to 100 % FM. The feed conversion ratio (FCR) and protein efficiency ratio (PER) did not differ significantly between all diets, but reduced FCR and increased PER were observed with a higher inclusion of cricket meal. A haematological examination of fish demonstrated no significant difference of red blood cells in all diets and white blood cells showed a significantly higher value in fishmeal-fed fish. On the other hand, haemoglobin and haematocrit significantly increased with increasing amounts of cricket meal in the diet. Antioxidant activity of CAT was higher in the 100 % CM group compared to fish fed other diets, whereas GST and SOD showed increasing trends with a higher incorporation of cricket, although insignificant differences were observed between all diets. These results suggest that cricket meal could be an alternative to fishmeal as a protein source in the African catfish diet.
77 citations
TL;DR: This review article summarizes and highlights the potential utilization of by-products generated during fish processing for gelatin extraction, and several technical challenges and directions of ongoing research are discussed.
Abstract: The current practice of fish processing generates large amounts of by-products, which can account for up to three-quarters of the total fish weight. Despite the presence of several valuable components in the fish processing discards, the latter are usually dumped into landfills or at sea, having potentially harmful environmental effects or end up as low commercial value products (e.g., white fish meal). Still, fish processing by-products can be considered as an alternative raw material for the preparation of high-protein ingredients, especially for the production of food grade gelatin due to the presence of large amounts of collagen in fish skins, scales, and bones. Although fish gelatin is an alternative to the commercially available mammalian gelatins, its production on a large commercial scale has been hampered, mainly, due to the inferior quality characteristics compared to its mammalian counterparts. This review article summarizes and highlights the potential utilization of by-products genera...
70 citations
TL;DR: Comparison of the distal intestinal proteome of Atlantic salmon revealed that the expressions of Alpha-2-HS-glycoprotein-like, Myosin-11 isoform X1 (My11) and Dihydrolipoyl dehydrogenase, mitochondrial-like (Dld) were altered by the microalgal feeding.
Abstract: Microalgal biomass is a potential feed ingredient that can replace fishmeal and ensure sustainability standards in aquaculture. To understand the efficacy of the defatted biomass from the marine microalga, Desmodesmus sp. a 70-day feeding study was performed with Atlantic salmon (Salmo salar) smolts. Three groups of fish (av. wt. 167 g) were offered either a control feed (without the microalga) or the microalga-containing (10/20%) feeds. At the end of the feeding period, the growth indices (condition factor, specific growth rate) and survival of the microalga-fed fish were not significantly different from the respective values of the control fish, but the feed conversion ratios were inferior. The proximate composition of the whole body of salmon from the three groups did not vary significantly. Compared to the control fish, the alga-fed fish had lower lipid content (10% alga-fed fish) in their fillet. The protein and lipid digestibility in the three feeds did not differ significantly, but the digestibility of energy in the 10% alga-feed was significantly lower than that of the control feed. Furthermore, comparison of the distal intestinal proteome of Atlantic salmon revealed that the expressions of Alpha-2-HS-glycoprotein-like (Ahsg), Myosin-11 isoform X1 (My11) and Dihydrolipoyl dehydrogenase, mitochondrial-like (Dld) were altered by the microalgal feeding. Examination of the physiological status of the fish based on the serum antioxidant capacities did not reveal any alga-feed-related differences. Moreover, the expression of the selected immune and inflammatory marker genes and the micromorphological observations did not indicate any aberration in the intestinal health of the microalga-fed fish. It is possible to include 20% of defatted Desmodesmus sp. in the feeds of Atlantic salmon.
69 citations
TL;DR: The microalga Pavlova viridis (=Diacronema viridis) as an n-3 polyunsaturated fatty acid (PUFA) source was evaluated and compared to Nannochloropsis sp.
Abstract: In the present study, the potential of the microalga Pavlova viridis (=Diacronema viridis) as an n-3 polyunsaturated fatty acid (PUFA) source was evaluated and compared to Nannochloropsis sp. in diets for juvenile European sea bass (Dicentrarchus labrax L.) (initial weight similar to 12.8 +/- 1.7 g) in an 8-week feeding trial. Six different isoenergetic and isonitrogenous test diets were used: (1) fish oil diet (FO), major lipid source fish oil (100 %), (2) basal diet, 40 % fish oil and 60 % plant oil (in equal parts rapeseed, sunflower, and linseed oil), (3) Pavlova 50 % (P50), 50 % of the fish oil of the basal diet was substituted by lipid content of P. viridis meal, (4) Pavlova 100 % (P100), 100 % of the fish oil of the basal diet was substituted by lipid content of P. viridis meal, (5) Nannochloropsis 50 % (N50), 50 % of the fish oil of the basal diet was substituted by lipid content of Nannochloropsis sp. meal, and (6) Nannochloropsis 100 % (N100), 100 % of the fish oil of the basal diet was substituted by lipid content of Nannochloropsis sp. meal. The specific growth rate was highest and feed conversion ratio was lowest in the P100 group (SGR 1.77 +/- 0.10 % day(-1); FCR 1.17 +/- 0.01), although not significantly different to the results for the FO and the other algae-groups. Furthermore, the sum of PUFA was also highest in the P100 group, followed by the P50, N100, N50, and B group (mainly due to the high content of linoleic and linolenic acids coming from plant oils and microalgal products) with the lowest levels in the FO group. The highest amounts of docosahexaenoic acid (DHA) of total fatty acids were found in the FO and B group, although not significantly higher than in groups P50 and P100. The significantly highest amount of eicosapentaenoic acid (EPA, % of total fatty acids) was in the P100 samples and the lowest amount was in samples of the basal group. The histological analyses of liver and intestine samples did not reveal any negative effects caused by the experimental treatments. Based on the basal diet, a 50 % fish oil replacement by Nannochloropsis sp. meal and a total replacement by P. viridis meal were possible without negative effects on the growth performance and nutrient utilization of juvenile sea bass.
67 citations
TL;DR: In this paper, the authors explored the attitude and behavior of Northern-Italian consumers of farmed fish fed on insects considering the different phases of the purchasing process: from a general claim to interest in sustainability about the use of marine resources to the attitude in to eating finfish products if fed on insect meals and finally to the decision to purchase.
Abstract: Aquaculture is assuming ever more importance in diminishing the pressure on wild stocks in the seas and to satisfy the demand of fish worldwide. Prices of feed used in farming fish are increasing, due to the rise in demand. Research on sustainable sources of feed was recently intensified, and insects as meal to substitute soybean and fish meals and fish oils seems a promising field. In particular, only very few papers have explored consumer interest in fish feed. The objective of this study is to explore the attitude and behavior of Northern-Italian consumers of farmed fish fed on insects considering the different phases of the purchasing process: from a general claim to interest in sustainability about the use of marine resources to the attitude in to eating finfish products if fed on insect meals and finally to the decision to purchase. In particular, the study utilizes a quantitative research methodology to explore factors affecting the gap between consumer intention and consumer behavior. Results indicate almost 90 % of consumers have a positive attitude to insect meal as feed and most of the respondents intend to purchase and eat farmed fish even though fed with insect meals. Moreover, interest is mainly affected by socioeconomic variables, knowledge of the issue and the interest attributed to origin and certification. Positive attitude is mainly influenced by interest in this issue and variables linked to appearance and price, whereas the willingness to buy fish fed on insect meals is closely linked to the importance of price and expected price for this kind of fish.
65 citations
TL;DR: Feed studies of typical freshwater fish species that show their essential fatty acid requirement can be satisfied by dietary C18 PUFA are confirmed, confirming that the LC-PUFA biosynthesis pathway is active in the African catfish C. gariepinus.
TL;DR: The present experiment clearly demonstrated that, freshwater fish juvenile Nile tilapia has a specific requirement level for dietary Se which cannot be met by regular feed and ambient water and supplements beyond the requirement level may have toxic effects in freshwater aquaculture.
TL;DR: It can be concluded that appropriate portions of different types of food waste could satisfy basic nutritional requirements of lower trophic level fish species such as grass carp and tilapia and upgrading the fish pellets by adding different supplements could further elevated the quality of feeds, leading to higher growth rates, and enhanced immunity of fish.
TL;DR: The results illustrate that zooplankton are not just a static food source for larger organisms, nor can they be resolved as very small fish, and their representation is of critical importance in size-spectrum models, and end-to-end ecosystem models more broadly.
Abstract: The evidence for an equal distribution of biomass from bacteria to whales has led to development of size-spectrum models that represent the dynamics of the marine ecosystem using size rather than species identity. Recent advances have improved the realism of the fish component of the size-spectrum, but these often assume that small fish feed on an aggregated plankton size-spectrum, without any explicit representation of zooplankton dynamics. In these models, small zooplankton are grouped with phytoplankton as a resource for larval fish, and large zooplankton are parameterized as small fish. Here we investigate the impact of resolving zooplankton and their feeding traits in a dynamic size-spectrum model. First, we compare a base model, where zooplankton are parameterized as smaller fish, to a model that includes zooplankton-specific feeding parameters. Second, we evaluate how the parameterization of zooplankton feeding characteristics, specifically the predator-prey mass ratio (PPMR), assimilation efficiency and feeding kernel width, affects the productivity and stability of the fish community. Finally, we compare how feeding characteristics of different zooplankton functional groups mediate increases in primary production and fishing pressure. Incorporating zooplankton-specific feeding parameters increased productivity of the fish community, but also changed the dynamics of the entire system from a stable to an oscillating steady-state. The inclusion of zooplankton feeding characteristics mediated a trade-off between the productivity and resilience of the fish community, and its stability. Fish communities with increased productivity and lower stability were supported by zooplankton with a larger PPMR and a narrower feeding kernel – specialized herbivores. In contrast, fish communities that were stable had lower productivity, and were supported by zooplankton with a lower PPMR and a wider feeding kernel – generalist carnivores. Herbivorous zooplankton communities were more efficient at mediating increases in primary production, and supported fish communities more resilient to fishing. Our results illustrate that zooplankton are not just a static food source for larger organisms, nor can they be resolved as very small fish. The unique feeding characteristics of zooplankton have enormous implications for the dynamics of marine ecosystems, and their representation is of critical importance in size-spectrum models, and end-to-end ecosystem models more broadly.
TL;DR: In general, the concentrations of all target metals were positively correlated with fish feed contents, whereas negative correlations were observed between the metal concentrations and water.
Abstract: This study focuses on the extent of Zn, Cu, Ni, Cd and Pb bioaccumulation in water, fish feed and the muscles of 40 rainbow trout (Oncorhynchus mykiss) from four farmsalong Haraz River, Mazandaran ...
TL;DR: It is concluded that inosine and low concentration of NBP (1%) could be effectively used as dietary supplements for better growth and health performance of Pagrus major.
TL;DR: The hypothesis that higher Hg content and lower caloric content make pelagic zooplankton prey greater sources of Hg for fish than nearshore benthic prey in lakes supports the hypothesis that habitat-specific foraging is likely to be a strong driver of variation in Hg levels within and between fish species.
TL;DR: Waste based feed pellets incorporated with Chinese medicinal herb extracts have the ability to enhance growth and immunity of fish and the use of Chinese medicinal herbs in aquaculture should be encouraged, in order to replace certain antibiotics known to impose environmental and health effects through the discharge of Aquaculture effluents.
TL;DR: The results showed that Japanese seabass has a relatively high tolerance to oils rich but high levels of C16:0 or C18:0 enriched lipid sources could reduce the feed efficiency and growth rate.
TL;DR: Dietary supplementation with bile components or lecithin in general did not improve endpoints regarding performance or gut health in Atlantic salmon, in clear contrast to what has been previously reported for rainbow trout.
Abstract: The present study was undertaken to gain knowledge on the role of bile components and lecithin on development of aberrations in digestive functions which seemingly have increased in Atlantic salmon in parallel with the increased use of plant ingredients in fish feed. Post smolt Atlantic salmon were fed for 77 days one of three basal diets: a high fish meal diet (HFM), a low fishmeal diet (LFM), or a diet with high protein soybean meal (HPS). Five additional diets were made from the LFM diet by supplementing with: purified taurocholate (1.8 %), bovine bile salt (1.8 %), taurine (0.4 %), lecithin (1.5 %), or a mix of supplements (suppl mix) containing taurocholate (1.8 %), cholesterol (1.5 %) and lecithin (0.4 %). Two additional diets were made from the HPS diet by supplementing with: bovine bile salt (1.8 %) or the suppl mix. Body and intestinal weights were recorded, and blood, bile, intestinal tissues and digesta were sampled for evaluation of growth, nutrient metabolism and intestinal structure and function. In comparison with fish fed the HFM diet fish fed the LFM and HPS diets grew less and showed reduced plasma bile salt and cholesterol levels. Histological examination of the distal intestine showed signs of enteritis in both LFM and HPS diet groups, though more pronounced in the HPS diet group. The HPS diet reduced digesta dry matter and capacity of leucine amino peptidase in the distal intestine. None of the dietary supplements improved endpoints regarding fish performance, gut function or inflammation in the distal intestine. Some endpoints rather indicated negative effects. Dietary supplementation with bile components or lecithin in general did not improve endpoints regarding performance or gut health in Atlantic salmon, in clear contrast to what has been previously reported for rainbow trout. Follow-up studies are needed to clarify if lower levels of bile salts and cholesterol may give different and beneficial effects, or if other supplements, and other combinations of supplements might prevent or ameliorate inflammation in the distal intestine.
TL;DR: The study findings confirmed that high-temperature extrusion-cooking process does not deactivate phenolic antioxidant compounds, which are present both in the Echinacea roots and in the final product.
TL;DR: The results of this study show that 40% of fish meal protein could be replaced by SBM in diets of juvenile P. ussuriensis without having a significant negative effect on growth or feed efficiency, but that higher dietary SBM levels reduce fish performance.
Abstract: An 8-week feeding trial was conducted to evaluate the effects of replacing fish meal with soybean meal (SBM) on growth, feed utilization, and nitrogen (N) and phosphorus (P) excretion of juvenile Pseudobagrus ussuriensis (initial average weight 0.50 ± 0.00 g). Seven isonitrogenous and isolipidic diets were formulated to contain SBM to replace fish meal protein at 0% (S0), 10% (S10), 20% (S20), 30% (S30), 40% (S40), 50% (S50) and 60% (S60) respectively. To investigate the effects of supplementation with crystalline amino acid to balance diet S60, one diet was formulated to add 0.30% methionine (SM60). The results showed that there was no significant difference in weight gain among fish fed S0, S10, S20, S30 and S40 diets, however, a significant reduction in this variable occurred when 50% and 60% of fish meal protein was replaced by SBM (P < 0.05). Apparent digestibility coefficients of dry matter, crude protein and phosphorus of diets were affected by dietary SBM levels. N and P excretion indicate that fish meal replacement by SBM led to an increase in N excretion, but led to a reduction in P excretion. No differences were detected in growth, feed utilization and N and P excretion between fish feed diets S60 and SM60. The results of this study show that 40% of fish meal protein could be replaced by SBM in diets of juvenile P. ussuriensis without having a significant negative effect on growth or feed efficiency, but that higher dietary SBM levels reduce fish performance.
TL;DR: Overall performance observed in the present experiments vouched the potential benefit of using chelated trace mineral, Cu, Zn & Mn premix in marine shrimp, Pacific white shrimp to promote the optimum growth, trace minerals saturation in shrimp body and tissue as well as to ensure the optimum enzyme activity and health of cultured shrimp.
TL;DR: The redirecting of small pelagics to human consumption will depend on the role of the state in Tanzania and South Africa in investing in post-harvest processing, and the role small-scale fisheries play in providing fish for food security needs to be understood in the context of economic viability.
Abstract: The group of small pelagic fish is the largest species group landed globally. A significant proportion of this nutrient-rich food is processed and lost to livestock feed, fish feed, fish oil, pet food and omega-rich vitamins. The nutritional importance of small pelagics as an easily digestible protein source, rich in essential lipids with fatty acids (EPA/DHA), essential amino acids, minerals and vitamins, is well known and documented. Small pelagics contain all the elements of a healthy and nutritionally optimal food source for humans and are an important contributor to the food and nutritional security of many poor, low-income households in developing countries. Large-scale and small-scale fisheries play an important role in contributing to food security and nutrition. Yet, all of the anchovy landings from large-scale fisheries are reduced to animal feed, fish oil and pet food in South Africa. The size of the species, labour costs and lack of incentives by the state are some of the challenges to redirecting anchovy for human consumption. This trend is also now prevalent in Tanzania, where most (84%) of the dagaa fished is reduced to fishmeal in Kenya, mainly to feed chickens. The main challenges are post-harvest handling and sanitation. The redirecting of small pelagics to human consumption will depend on the role of the state in Tanzania and South Africa in investing in post-harvest processing. The role small-scale fisheries play in providing fish for food security needs to be understood in the context of economic viability and of how data are reported in this sector as compared to large-scale fisheries.
TL;DR: The dynamics of nitrogen (N) and phosphorus (P) was studied in mariculture areas around Bolinao and Anda, Philippines to examine its possible link to recurring algal blooms, hypoxia and fish kills.
TL;DR: Two PE species were identified in OP,OP diet and fish fed with OP diet and not in FO diet, which might be an indication that these substances are likely to be the key polar phospholipids that have the ability to be in vitro PAF inhibitors, i.e. inhibit the formation of atherosclerotic plaques in blood arteries.
TL;DR: Ethanol extract of the brown macroalga S. vulgare could be a promising antibacterial and a new active agent against MDR A. hydrophila, which could been a major causative agent of Nile tilapia fish diseases and is recommended as a natural and effective source to enhance the growth performance of Niletilapia.
TL;DR: Overall conclusion from the experiment is that WSP can be used as a processing aid for the fish feed industry, serving multiple purposes as nutrient, plasticizer and binder in extruded fish feed.
Abstract: The aim of this research was to investigate the effect of water-soluble protein (WSP) as a plasticizer in the fish feed extrusion process and the impact on physical pellet quality. A three-factor central composite design was used to study the influence of the variables WSP in the feed mix, and steam and water addition in the extruder. Regression models with r2 in the range of 0.862–0.976 (P < 0.001) were established for specific mechanical energy (SME), pellet hardness, cutting strength, sectional expansion index, length, bulk density, oil adsorption capacity and extrudate flow-starting temperature (Tf). Addition of WSP had a positive effect on SME and improved the physical pellet quality, while moisture had the opposite effect. Expansion parameters showed a complex relationship and were influenced by all the studied process variables. Increase in WSP and moisture content had a comparable effect on Tf reduction. This opens up the possibility to obtain a satisfactory ‘cook’ at reduced moisture level with a potential for significant reduction of the energy consumption during drying of the extrudate. Overall conclusion from the experiment is that WSP can be used as a processing aid for the fish feed industry, serving multiple purposes as nutrient, plasticizer and binder in extruded fish feed.
TL;DR: Results indicated that the highest survival, weight gain and specific growth rate were recorded by fish fed D5 and D6 being statistically different from other treatment groups, and no significant differences were found in the chemical composition of whole body of fish fed different tested diets.
Abstract: A total of six treatments, ie, negative control group (D1), B licheniformis 7×107 CFU g−1 diet (D2); 1ml essential fennel oil (EFO) kg-1 diet (D3); 1 ml essential garlic oil (EGO) kg-1 diet (D4); B licheniformis 7×107 CFU g−1 +1 ml EFO kg-1 diet (D5) and B licheniformis 7×107 CFU g−1 +1 ml EGO kg-1 diet (D6) were added to the diets of Nile tilapia, Oreochromis niloticus to investigate the effects of the respective treatments on the growth, feeding behaviour, hematological and biochemical indices Fish (188 ± 012 g) were distributed at a rate of 20 fish per 100-L aquarium and three aquaria have been assigned for each treatment At the end of the experiment (84-day), results indicated that the highest survival, weight gain and specific growth rate were recorded by fish fed D5 and D6 being statistically different (P<005) from other treatment groups Whereas, the best feed conversion ratio and protein efficiency ratio were observed in D3, D4, D5 and D6 compared with other treatment groups Fish feed D6 were higher in mouth wrestling and chasing behavior Fish fed D5 and D6 significantly higher (P<005) hematocrit and hemoglobin values also, was effectively enhanced aspartate aminotransferase, alanine aminotransferase, total protein and globulin in comparison to the other treatments No significant differences were found in the chemical composition of whole body of fish fed different tested diets
TL;DR: In this article, the authors evaluated the potential environmental impacts of producing gilthead seabream in an offshore sea farm exposed to storms in the Spanish Mediterranean Sea and found that the component of the system with the greatest potential environmental impact was fish feed, especially the raw material used.
Abstract: Life cycle assessment is used in this study to evaluate the potential environmental impacts of producing gilthead seabream in an offshore sea farm exposed to storms in the Spanish Mediterranean Sea. The farming methods used can be considered as “basic” since no centralized or automatic food distribution system exists and there is no control system. This study aims to identify the main hotspots under these conditions and to propose and compare viable alternatives to them. Contribution analysis found that the component of the system with the greatest potential environmental impact (48% of the overall impact) was fish feed, especially the raw material used. Other contributory factors were the fuel consumed by the vessels operating in the farm (35%), the dumping of N and P in the environment due to the metabolism of the fish (12%), the cages and their anchorage system (5%). A sensitivity analysis showed that a significant reduction in potential environmental impact can be achieved by increasing feeding efficiency. Feed formulation in raw materials is also an important factor and could serve to diminish overall adverse effects. A balance needs to be found between productive performance (growth, survival and feed conversion rate), feed price and its influence on production costs and the overall environmental consequences.