Search

The effect of partial or total dietary substitution of fishmeal (FM) by vegetal protein sources on growth and feed efficiency was carried out in on-growing gilthead sea bream (mean initial weight 131 g). The Control diet (FM 100) contained FM as the primary protein source, while in Diets FM 25 and FM 0 the FM protein was replaced at 75% and 100%, respectively, by a vegetable protein mixture consisting of wheat gluten, soybean meal, rapeseed meal and crystalline amino acids. Diets FM 25 and FM 0 also contained krill meal at 47 g/kg in order to improve palatability. At the end of the trial (after 158 d), fish survival was above 90%. Final weight and the specific growth rate were statistically lower in fish fed the Control diet (361 g and 0.64%/d), compared with 390–396 g and 0.69–0.70%/d after feeding vegetal diets. No significant differences were found regarding feed intake and feed conversion ratio. The digestibility of protein and amino acids (determined with chromium oxide as indicator) was similar in all diets. The blood parameters were not significantly affected by treatments. The activity of trypsin and pepsin was significantly reduced after feeding Diet FM 0. In the distal intestine, the villi length in fish fed Diet FM 25 was significantly longer and the intestine of the fish fed the FM 100 diet showed a smaller number of goblet cells. In conclusion, a total FM substitution by a vegetal mix supplemented with synthetic amino acids in on-growing sea bream is feasible. [ABSTRACT FROM AUTHOR]

The present study was conducted to investigate the effects of dietary methionine on growth performance, protein metabolism, immunity and resistance to heat stress of abalone Haliotis discus hannai. Seven isonitrogenous (about 32% of crude protein) and isolipidic (about 3% of crude lipid) diets were designed with graded levels of methionine (0.46%, 0.77%, 0.97%, 1.19%, 1.41%, 1.71% and 2.07%, respectively). The experimental diets were named as M1 (control), M2, M3, M4, M5, M6 and M7, respectively. An 84-day feeding trial was conducted in sea cages (40 cm × 35 cm × 70 cm) for abalones (initial body weight: 4.10 ± 0.01 g), which were fed once every two days. The results showed that the biomass gain (BG) of abalone significantly increased (from 560.20 g to 643.83 g) with the increasing dietary methionine levels from 0.46% to 1.19%, and then decreased (from 643.83 g to 484.29 g) (P < 0.05). Based on the broken-line regression analysis of BG, the requirement of dietary methionine for abalone was determined to be 0.99% (dry matter of diet). The highest trypsin activity (862.10 U/mg prot.) and α-Amylase activity (0.28 U/mg prot.) in the intestine of abalone were observed in the M4 and M5 group, respectively. In the digestive gland, the gene expression of mtor , s6k and eif4e showed a significant quadratic trend with the increasing dietary methionine levels, and all of them reached their highest values in the M4 group. The highest mRNA level of gcn2 was observed in the M1 group. The glutathione content and total anti-oxidative capacity in cell-free hemolymph (CFH) were significantly increased as dietary methionine levels increasing from 0.46% to 1.19%, and then decreased (P < 0.05). The lowest gene expression level of keap1 , nf-κb and tnf-α , and the highest gene expression level of nrf2 and iκbα in the digestive gland were found in the M4 group. After the heat stress test at the end of feeding trial, the minimum falling rate (19.44%) and the highest gene expression level of hsp70 and hsp90 in the digestive gland of abalone were found in the group with 1.19% of dietary methionine. In conclusion, appropriate dietary methionine (0.97%–1.19%) could improve the growth, protein synthesis, immunity and resistance to heat stress of abalone. • Effects of graded levels of dietary methionine (0.46–2.07%) on abalone were studied. • Appropriate dietary methionine (0.97–1.19%) improved growth and feed utilization of abalone. • Based on the broken-line analysis of weight gain rate, the requirement of dietary methionine for abalone was determined to be 0.99%. • The mTOR signaling pathway was significantly activated by 0.97–1.19% of dietary methionine. • Appropriate dietary methionine (0.97%–1.19%) enhanced the immunity and resistance to heat stress of abalone. [ABSTRACT FROM AUTHOR]

Aquaculture is growing to meet the increasing demand for aquaculture products but is not free of environmental impacts. One solution is to improve how feed are formulated, limiting the environmental impact of fish production. Multiobjective (MO) formulation, which aims for a compromise between lower cost and lower environmental impacts, appears to be a promising solution to reduce the environmental footprint of aquaculture production. The objectives of this study were to design an eco-friendly trout feed (ECO-diet) using MO formulation and to compare its zootechnical and environmental performances to those of a commercial feed (C-diet) containing 16% fishmeal and 6.5% fish oil. MO formulation changed the composition of the diet greatly, which decreased environmental impacts of the feed as well as its price. It increased the number of ingredients used but reduced the use of fishmeal and fish oil by half. MO formulation also led to the elimination of soy products, faba bean, and gluten in favour of processed animal co-products that have high protein contents and low climate change impact. Rapeseed oil also disappeared from the ECO-diet due to its major contribution to land use, eutrophication, and acidification and, to a lesser extent, climate change. Overall, the ECO-diet had high digestibility, which differed little from that of the C-diet. Mean fish body weight after 12 weeks of growth did not differ significantly from that obtained with the C-diet, but analysis of fish growth curves indicated that the ECO-diet could lead to lower growth in the long term. This observation was consistent with the significantly lower feed intake in fish fed the ECO-diet. The decrease in impacts observed at the feed level was also observed at the farm level, although less so for eutrophication, non-renewable energy use, and climate change calculated per kg of body weight gain. MO formulation is a useful tool to reduce the environmental footprint of aquaculture production without compromising animal performances or necessarily increasing production cost. • Multiobjective (MO) formulation reduced the environmental footprint of fish feed. • Feeding the ECO-diet yielded satisfactory growth performance of trout. • Feeding the ECO-diet decreased environmental impacts of trout production. • MO formulation reduces aquaculture reliance on fishmeal and fish oil. [ABSTRACT FROM AUTHOR]

The role of transportation vehicles, pig movement between farms, proximity to infected premises, and feed deliveries has not been fully considered in the dissemination dynamics of porcine epidemic diarrhea virus (PEDV). This has limited efforts for disease prevention, control and elimination restricting the development of risk-based resource allocation to the most relevant modes of PEDV dissemination. Here, we modeled nine pathways of between-farm transmission represented by a contact network of pig movements between sites, farm-to-farm proximity (local transmission), four distinct contact networks of transportation vehicles (trucks that transport pigs from farm-to-farm and farm-to-markets, as well as trucks transporting feed and staff), the volume of animal by-products in feed diets (e.g., fat and meat-and-bone-meal) to reproduce PEDV transmission dynamics. The model was calibrated in space and time with weekly PEDV outbreaks. We investigated the model performance to identify outbreak locations and the contribution of each route in the dissemination of PEDV. The model estimated that 42.7% of the infections in sow farms were related to vehicles transporting feed, 34.5% of infected nurseries were associated with vehicles transporting pigs between farms, and for both farm types, local transmission or pig movements were the next most relevant transmission routes. On the other hand, finishers were most often (31.4%) infected via local transmission, followed by the vehicles transporting feed and pigs between farms. Feed ingredients did not significantly improve model calibration metrics, sensitivity, and specificity; therefore, it was considered to have a negligible contribution in the dissemination of PEDV. The proposed modeling framework provides an evaluation of PEDV transmission dynamics, ranking the most important routes of PEDV dissemination and granting the swine industry valuable information to focus efforts and resources on the most important transmission routes. [ABSTRACT FROM AUTHOR]

A 6-week broiler study was conducted to evaluate whether subjecting the intestinal microflora of broilers to the effect of weekly variations in feed ingredients could be ameliorated by the inclusion of yeast-derived feed additives: a yeast cell wall extract ( YCW), live yeast culture ( LY) or their combination ( YCW + LY). Recent changes in ingredient prices have motivated producers to formulate diets not necessarily based primarily on corn and soya bean meal. Intestinal microflora in birds can vary significantly based on the ingredient composition of their diet, and the make-up of the flora can influence overall bird performance. Within the three nutrient phases of this study, birds were fed either a traditional corn-soya ingredient profile or a variable-ingredient regimen, which had weekly changes in the ingredient composition. There were consistent ameliorative effects of the yeast treatments in both the corn-soya and the variable-ingredient groups throughout all 6 weeks, with the YCW + LY combination showing a reduced effect when compared to either product fed alone. The effectiveness of YCW and LY on ameliorating the effects of weekly ingredient variations appeared most effective during the starter and grower phases, but was less significant during the sixth week. [ABSTRACT FROM AUTHOR]

A quantitative analysis of the essential mineral content (mg kg−1 dry weight) was carried out in 31 samples, including molluscs, crustaceans, fish and meals in an attempt to identify those most suitable for formulating cephalopod diets. The mineral ratios ( MR: content in the test sample/content in whole Octopus vulgaris) were used as index of nutritional quality. Both crustaceans and oysters presented an optimal profile that covered the macro- and microelements composition of O. vulgaris. These samples differed from the rest by their higher Ca, Mg, B, Cu and Zn contents based on a principal component analysis. Fish were deficient in macroelements, such as Na ( MR: 70-420 g kg−1) and Mg ( MR: 220-690 g kg−1), but would be good source of K, Ca and P. Most fish were also deficient in Fe, Zn and Cu, although the copper content would be the most affected ( MR: 3-130 g kg−1). Fish and krill meals showed a high content of Ca and P, although both would be deficient in Na ( MR: 440-470 g kg−1) and Cu (130-540 g kg−1), along with K, Fe and Zn in krill and Mg and B in fish. Among the plant meals, sunflower and soybean were the most appropriate, presenting higher total content of minerals and MRs above 1000 g kg−1 for all minerals, except Na, Cu and Zn. [ABSTRACT FROM AUTHOR]

A set of prediction equations to estimate the nitrogen-corrected apparent metabolizable energy (AMEn) of individual ingredients and diets used in the poultry feed industry was evaluated. The AMEn values of three energy ingredients (maize, sorghum and defatted maize germ meal), four protein ingredients (soybean meal, maize gluten meal 60% crude protein, integral micronized soy and roasted whole soybean) and four diets (three containing four feedstuffs, complex diets, and one containing only corn-soybean meal, basal diet) were determined using a metabolism assay with male broilers from 1 to 7, 8 to 21, 22 to 35, and 36 to 42 days old. These values were compared to the AMEn values presented in the tables of energy composition or estimated by equation predictions based on chemical composition data of feedstuffs. In general, the equation predictions more precisely estimated the AMEn of feedstuffs when compared to the tables of energy composition. The equation AMEn (dry matter [DM] basis) = 4,164.187+51.006 ether extract (% in DM basis)-197.663 ash-35.689 crude fiber (% in DM basis)-20.593 neutral detergent fiber (% in DM basis) (R2 = 0.75) was the most applicable for the prediction of the energy values of feedstuffs and diets used in the poultry feed industry. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effects of diet composition on phytate (InsP6) degradation in dairy cows. In Experiment 1, four diets that differed in the amount and source of phosphorus (P) were fed to 24 lactating cows in a 4 × 4 Latin Square design. The control diet (Diet C) contained 4.18 g P/kg dry matter (DM). Diet MP contained additional mineral P (5.11 g P/kg DM), Diet RS contained rapeseed and rapeseed meal as organic P sources (5.26 g P/kg DM) and Diet RSM contained rapeseed meal and rapeseed oil (5.04 g P/kg DM). Total P (tP) and InsP6excretion in faeces were measured. In Experiment 2, we used a rumen simulation technique (Rusitec) to estimate ruminal disappearance of tP and InsP6from Diets C, MP and RSM. In Experiment 1, tP concentration in faeces increased with tP intake and was highest for Diets RS and RSM. The source of supplemented P had no influence on tP digestibility, but tP digestibility was reduced for Diets MP, RS and RSM in comparison to that for Diet C. InsP6disappearance decreased in Diet MP (85.0%) and increased in Diets RS (92.7%) and RSM (94.0%) compared to that in Diet C (90.0%). In Experiment 2, P source influenced ruminal tP disappearance (Diet MP, 78.6%; Diet RSM, 75.3%). InsP6disappearance for Diet C (98.1%) was higher than that for Diets MP (95.6%) and RSM (94.9%). The results confirmed the high potential of ruminants to degrade InsP6, but differences in diet composition influenced InsP6disappearance. Further studies of the site of InsP6degradation are required to understand the relevance of InsP6degradation for the absorption of P. [ABSTRACT FROM PUBLISHER]

Since it started as an organized economic activity, poultry production has been undergoing an evolution toward the optimization of its feed formulation features. Notably, advances in the knowledge of birds' nutrient requirements have allowed recommendations that are increasingly closer to the needs of the birds. Over time, availability of nutrients and energy has been incorporated into those recommendations, especially to compensate for the variability in the digestibility of nutrients originating from variable feed ingredient sources. Instead of using the total energy and nutrient content, current tables of nutrient recommendations provide an estimate of the digestible fractions of the nutrients in ingredients. For instance, nonphytate P is preferred instead of total P to account for the unavailable phytate P, and digestible amino acids to account for the differences in digestibility of amino acids in different ingredients, whereas energy is usually expressed as a proportion that has been digested and metabolized (AME). With the increasing interest in the use of exogenous enzymes in poultry feeds, special attention is directed to the feed substrates such that an added enzyme can match it, forming an enzyme-substrate complex that will be followed by a chemical reaction within the gastrointestinal tract. As a consequence of a degradation reaction, nutrients released can be absorbed and metabolized. In general, nutritional data banks used in linear feed formulation software have limited data on the proportions of fractions of ingredients that are indigestible. Therefore, estimations of the presence of many substrates in the feeds, and therefore the benefits of adding exogenous enzymes, are frequently limited because of the scarcity of adequate information. The objective of this review paper is to provide insights into the use of expanded nutrient databanks to include all the molecules considered potentially indigestible for poultry such that the inclusion of exogenous enzymes allows the estimation of the values of the product originated by their hydrolysis. [ABSTRACT FROM AUTHOR]

In 2011, aquaculture accounted for almost 64 million MT of fish, crustaceans and mollusks (FAO, 2012). Fish meal has historically been the protein source of choice in aquatic feeds, but global supplies have reached a plateau making it less available and more expensive. As a consequence, the use of cheaper proteins made from processed plant proteins, byproducts from agriculture, fisheries or the slaughtering of terrestrial production animals was popularized within the aquaculture feed industry. Although these alternative ingredients may contain a crude protein (CP) content comparable to fish meal, they may be less digestible and deficient in one or more of the ten essential amino acids (EAAs). This has required the adoption of more modern formulation approaches which take into account nutrient availability, especially in regard to EAAs. EAA requirements have been established for a number of species of fish and shrimp. Methionine (Met) followed by lysine (Lys) are the first limiting amino acids in plant and rendered animal byproducts. Formulating for EAAs by simply increasing the dietary inclusion levels of the feedstuffs that contain intact sources of the targeted EAAs can lead to overformulated feeds with excessive levels of CP and other nutrients. A more rational approach is to supplement the diet with crystalline amino acids (CAAs). A first step to the application of a nutrient-based formulation approach is knowledge of the digestible EAA content of the ingredients available for use in the formula. It is highly desirable to formulate on a CP, EAA and energy digestibility basis in line with current formulation practices of most modern feed companies. Further expansion of current EAA digestibility values across ingredients and farmed aquatic species will further enable nutrient based formulation. By formulating on an EAA basis across farmed aquatic species, nutritionists have realized least cost formulation opportunities with the use of CAAs which are now available throughout the world at accessible prices. The CAAs mostly used by the animal feed industry, in order of usage, are the following: dl-methionine or Met analogs, l-lysine, l-threonine, l-tryptophan, l-isoleucine and l-valine. Met and Lys are the most currently used due to their wide availability and importance as most limiting EAAs in plant protein ingredients, such as soy and corn based meals. There is a relatively wide variation in the dietary Met and Lys requirement values for farmed fish and shrimp. This is due to differences in species requirements, culture systems, developmental stage and composition of experimental diets. The dietary Met requirements for fish and shrimp range from 0.5 to 1.5% and from 0.7 to 0.9% of the diet, respectively (NRC, 2011). The dietary Lys requirements range from 1.2% to 3.3% of the diet for cultured fish and from 1.6 to 2.1% of the diet for cultured shrimp. Appropriate dietary Met and Lys levels improve the use of other EAAs because they have the ability to reduce the oxidation rate of other amino acids. The present review discusses bioavailability, requirements and sources of EAAs and practical considerations for their application in aquaculture feeds. The appropriate supplementation of crystalline amino acids in feeds for fish and shrimp represents an opportunity to reduce formulation costs in the face of the volatile commodity market of protein ingredients and the short supply of fish meal. Competitiveness in the aquatic animal feed industry today depends upon application of modern and environmentally-sound formulation techniques based on nutrient value and supplementation with crystalline EAA to meet animal nutrient requirements. [ABSTRACT FROM AUTHOR]

Eight isonitrogenous (approximately 35 % crude protein) and isocaloric (17.58 kJ g) diets incorporating raw and fermented sesame oilseed meal replacing other feed ingredients including fishmeal at 10, 20, 30 and 40 % levels by weight into a fishmeal-based reference diet (RD) were fed to rohu, Labeo rohita, fingerlings (mean initial weight 3.19 ± 0.09 g) for 80 days. Two phytase-producing bacterial strains (LF1 and LH1 of Bacillus licheniformis) isolated from the foregut and hindgut regions of adult L. rohita were used for fermentation of oilseed meal for 15 days at 37 ± 2 °C. Fermentation of sesame seed meal was effective in significantly reducing the crude fibre content and anti-nutritional factors such as tannins and phytic acid and enhancing available free amino acids, free fatty acids and mineral concentration. In terms of growth, feed conversion ratio and protein efficiency ratio, 30 % fermented oilseed meal incorporated diet resulted in a significantly ( P < 0.05) better performance of rohu fingerlings. In general, growth and feed utilization efficiencies of diets containing fermented oilseed meal were superior to diets containing raw meal. The apparent digestibility of protein, lipid, ash and minerals (phosphorus, calcium, manganese, copper and iron) was significantly ( P < 0.05) higher in fish fed diet containing 30 % fermented oilseed meal in comparison with those fed RD. The maximum deposition of protein in the carcass was recorded in fish fed the diet containing 30 % fermented seed meal. [ABSTRACT FROM AUTHOR]

Five groups of broiler chickens were raised on feed containing varying substitutions of single cell protein from preprocessed waste activated sludge (pWAS) in varying compositions of 0:100, 25:75, 50:50, 75:25, and 100:0 pWAS: fishmeal by mass. Forty chickens per batch were evaluated for growth rate, mortality rate, and feed conversion efficiency (ηϵ). The initial mass gain rate, mortality rate, initial and operational cost analyses showed that protein from pWAS could successfully replace the commercial feed supplements with a significant cost saving without adversely affecting the health of the birds. The chickens raised on preprocessed WAS weighed 19% more than those raised on fishmeal protein supplement over a 45 day test period. Growing chickens on pWAS translated into a 46% cost saving due to the fast growth rate and minimal death losses before maturity. [ABSTRACT FROM AUTHOR]

Protective solid carriers are commonly added to probiotic cultures prior to drying. Their formulation is not trivial and depends on the drying conditions applied. In this study, we systematically investigated the influence of formulation parameters on the survival of Lactobacillus plantarum WCFS1 after drying. Low molecular weight carbohydrates (less than 2kDa) with high glass transition temperatures provided the highest level of protection at both low (25°C) and high (50°C or higher) drying temperatures. Low molecular weight carbohydrates may provide stabilization by closely interacting with the lipid bilayer of the cell membranes. Meanwhile, carbohydrates with high glass transition temperatures probably provide stabilization via fixation of the cells in a glassy powder. Furthermore, adequate amounts of solid carrier are required to sufficiently stabilize the cells during drying. During drying, crystallization of solid carriers may occur. Depending on the crystal geometry, crystallization can be either beneficial (e.g. with mannitol or sorbitol) or detrimental (e.g. with lactose) to cell survival. Finally, the effect of formulation on cell viability during storage was studied. A decimal reduction time of approximately 300days was observed when spray dried L. plantarum WCFS1 was stored at temperatures below 40°C. The outcome of this study was used as a basis to construct a generalized diagram to indicate the combinations of formulation and drying conditions to maximally retain viability and operate dryers at high efficiency. [ABSTRACT FROM AUTHOR]

Tilapia is the second most farmed fish group worldwide and over the past decade has quadrupled in production, largely due to their many characteristics conducive to aquaculture conditions as well as to the high marketability and relatively stable market prices. To keep pace with this rapid expansion, tilapia aquaculture will rely increasingly on more sustainable practices, but this must not be at the expense of decreased productivity, increased cost or compromised product quality. Since feed constitutes the major operating cost of tilapia farming, understanding their nutritional requirements, factors that may influence these requirements and implementing the most appropriate feeding management strategy is essential for the continued sustainability and scalability of the global tilapia industry. This review addressed these concerns by providing an overview of published nutrient requirement data and offered practical recommendations to the nutrition and feeding management of farmed tilapia, from broodstock to finishing feeds. The first section of this review extensively discusses the dietary protein/amino acids, lipids/fatty acids, carbohydrates, vitamin and mineral requirements of tilapia. Alternatives to marine-based ingredients, which are used increasingly in tilapia feeds, are also discussed. This is followed by discussing practical feed management aspects at the commercial farm level including feed formulations, feed types and feeding rates/frequency throughout the culture cycle. Recent research indicating significant differences in nutrient requirements and utilization efficiencies of improved tilapia strains versus non-improved strains are highlighted. This review aims to provide a comprehensive overview of tilapia nutrition and thus contributes to the continued global expansion of tilapia farming and the demand for their products. [ABSTRACT FROM AUTHOR]

A study was conducted to determine the predictability of energy balance and energy efficiency by using dietary chemical composition. Closed-circuit indirect calorimetry was used to determine the apparent metabolisable energy (AME), respiratory quotient, heat increment (HI), net energy (NE) and ratio of NE to AME (NE:AME) of a series of diets with varying levels of chemical constituents. Diets were analysed for DM, gross energy, protein, fat, ash, crude fibre, acid detergent fibre, neutral detergent fibre, starch, sugars (mono- and disaccharides), and soluble, insoluble and total non-starch polysaccharides. Ross 308 male broilers were acclimatised to chambers and diets for 3 days and 12 days, respectively, before O2 consumption and CO2 expiration were measured gravimetrically. Gross energy of feed consumed and excreta voided were measured and AME was calculated. Heat production was calculated using the Brouwer equation based on O2 and CO2. After taking fasting heat production into account by using a value of 450 kJ/BW[sup 0.70], HI was determined. NE was calculated as AME minus HI. The results showed high predictability of AME (R² = 0.89) and NE (R² = 0.85) by using chemical components. HI was less predictable (R² = 0.25). Efficiency of energy utilisation (NE:AME) was predicted (R² = 0.40). Closed-circuit calorimetry was found to be useful for evaluating the contribution of the chemical components of feed ingredients to the efficiency of energy utilisation in broilers. These results may be used to reduce energy costs in broiler feed formulation. Net energy values of raw materials are derived from prediction equations that take into account energy lost as wasted heat. The equations are produced by measuring heat produced in birds fed diets varying in nutrients and other chemical components. The use of a net energy system to formulate broiler feeds has the potential for significant cost savings. [ABSTRACT FROM AUTHOR]

The amino acid composition and protein levels of three species of cephalopods ( Octopus vulgaris, Loligo gahi and Todarodes sagittatus), the natural diets of common octopus ( O. vulgaris) and different kinds of meals were determined in order to optimise the content of these nutrients in artificial feeds. Arginine, leucine and lysine were the most abundant essential amino acids in cephalopods, while glutamate and aspartate represented the main non-essential amino acids. Arginine and leucine were the limiting amino acid in most samples, with maximum Chemical Score values for mussel (79-98 %), squid (84 %) and crustaceans (65-91 %); medium for fish (41-70 %); and minimum for meals (29-64 %). Mussel, squid, crustaceans and fish showed a high essential amino acid index according to Oser (OI: 88-99 %) suggesting a suitable amino acid balance. The protein from animal meals (fish and krill) covered all the essential amino acids except arginine and lysine in fish meal. The vegetable meal presented the worst amino acid balance (OI: 74-89 %) with several deficiencies in essential amino acids, including arginine, threonine, lysine and methionine. Supplementation with arginine or leucine and protein complementation of crustaceans and bivalves with fish or animal meal are proposed as alternatives for improving the performance of protein in feed for cephalopods. [ABSTRACT FROM AUTHOR]

Future food systems aim to achieve improved resource use efficiency and minimized environmental footprint through a circular bioeconomy-based approach. Aquaponics is a hallmark of such circular food production. The image of a circular nutrient utilization efficiency in aquaponics is often weakened by the daily use of additional inorganic fertilizers in such systems. As circular bioeconomy greatly emphasizes developing bio-based solutions, the presented novel inventory 'TilaFeed' and its associated utility tools is a step towards achieving more circular nutrient utilization and bioeconomy in future aquaponics. Through the formulation of tailored fish feed that is compatible with aquaponic systems' needs (e.g. plant nutrient requirement, mineralization efficiency of microbial sludge digesters), the objectives of TilaFeed are (i) to solve nutrient constraints in aquaponic systems, both for fish and plants; (ii) to avoid or strongly limit artificial fertilizer use in aquaponics by smartly tailored aquafeeds; and (iii) to equip system managers with decision-making tools for improved nutrient planning of their aquaponic systems. TilaFeed is a bio-based inventory. It integrates material (nutrient) flow information from feed to fish (in-vivo nutrient partitioning, forms of excretion) to environment (in-situ nutrient loading, nutrient forms) and primary producers (mineralization by microbes, available nutrients to plants). Based on TilaFeed-Model, feed for future aquaponics may be more precisely formulated with the principle that nutrients are not only a resource for fish, but excreted nutrients from fish (feed) also fertilize the microbes and plants., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Abstract: With the aim of reducing the environmental impacts of poultry feed, a database of the impacts of feed components destined for formulation was constructed using the Life Cycle Assessment (LCA) method. We used linear programming to create least cost feed formulas for fast-growing broiler (FGB), slow-growing broiler (SGB, i.e. quality label), laying hen and for three contrasting feed-cost situations (January 2006, December 2007 and March 2009). We focused on Eutrophication Potential (EP, a regional impact) and Climate Change (CC, a global impact) which were constraints to formulate low-impact poultry feed. The effects of using these constraints on feed cost and the use of feed components were investigated for a feed production plant in Bretagne (western France). Environmental impacts of poultry feed increased with the energy and protein content of the formula and were affected by the relative costs of feed components. FGB formulas had the highest impacts, followed by formulas for SGB and laying hens. The search for a minimum level of EP and CC of the formula decreased its impacts by 1–8% and by 1–12% respectively, and increased its cost by 2–8%, depending on the type of feed and the feed-cost situation. Impact reduction was obtained by partial substitution of soybean meal and cereals by rapeseed meal, grain legumes and co-products (wheat bran, gluten). Furthermore, 70% of the potential reduction of the EP and CC impacts could be obtained at a modest (0.5–4%) increase in the cost of the formulas. Some other ways to reduce feed impacts were explored, such as taking into account the geographic origin of maize crops and adopting a modified regulatory constraint for SGB formulas. It is important to continue this study by taking into account the whole life cycle of poultry production. [Copyright &y& Elsevier]

Copyright of Archivos de Medicina Veterinaria is the property of Universidad Austral de Chile, Facultad de Ciencias Veterinarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Two experiments were done to evaluate the effects of poultry meal (PM), meat meal (MM) or solvent-extracted soybean meal (SBM) inclusion on the performance of Australian snapper Pagrus auratus. In each experiment, test feeds were formulated with similar contents of digestible protein (DP) and digestible energy (DE) using previously determined digestibility coefficients for this species. In experiment 1, groups of snapper (initial weight 14 g) were fed 4 feeds containing 360, 480, 610 or 730 g kg PM; 3 feeds containing 345, 320 or 500 g kg MM; 3 feeds containing 420, 600 or 780 g kg SBM. In experiment 2, groups of snapper (initial weight 87 g) were fed 3 extruded test feeds that contained combinations of PM, MM, SBM or blood meal (BM) which replaced all but 600, 250 or 160 g kg of fishmeal in respective diet formulations. Both experiments included a proprietary extruded aquafeed (COM) to benchmark fish performance. In experiment 1, weight gain was highest in snapper fed feeds containing 360, 345 or 420 g kg of PM, MM or SBM, respectively, and was similar ( P > 0.05) to snapper fed the COM feed. Nonetheless, weight gain and protein retention efficiency tended to decrease as the amount of each test ingredient was increased. Relative feed intake was not affected by the inclusion level of PM, MM or BM, but declined significantly in snapper fed diets containing 600 or 780 g kg SBM. Feeding behaviour indicated fish found these feeds unpalatable. In experiment 2, the harvest weight of snapper fed the 3 extruded test feeds was similar ( P > 0.05), but lower than snapper fed the COM feed (i.e. 234 vs. 256 g). Feed conversion ratio (FCR) was best in snapper fed the COM feed (FCR = 1.53); however, the FCR of snapper fed feeds containing 160 (FCR = 1.66), 250 (FCR = 1.70) or 600 g kg fishmeal (FCR = 1.60) was not different ( P > 0.05). Australian snapper will readily accept feeds containing high levels of PM, MM or SBM and feeds containing these ingredients will support rapid weight and protein gain with little affect on whole body composition. In combination, these feed ingredients were able to replace all but 160 g kg of fishmeal in an extruded test feed. As such, they serve as valuable alternatives to fishmeal and extend the manufacturing options available to aquafeed producers. [ABSTRACT FROM AUTHOR]

Abstract: A simplified ration optimization method was applied to a beef cattle fattening system to evaluate the utilization of food by-products under various situations. The method was extended to reduce feed costs (i.e., economic factors) and nitrogen and phosphorus excretions (i.e., environmental factors) by introducing penalty coefficients of nitrogen and phosphorus contents in each ingredient of the diet in the objective function in traditional linear programming. Six regional food by-products, five commercial concentrates and two roughages were used as ingredients of the fermented total mixed ration. Constraints for the feed formulation were based mainly on nutrient requirements in the Japanese Feeding Standard for Beef Cattle. The replacement price (or acquisition cost) of food by-products was defined as the maximum price of food by-products when the feed cost with the use of food by-products was below the cost with the use of conventional concentrates. The results showed that although the replacement prices were not greatly affected by the penalty levels, they were associated with the changes in the substitution rate of food by-products for concentrates and the price of concentrates. The replacement prices were about 16 (yen/kg, as-fed basis) against the present price level of concentrates, when food by-products were substituted for a half of concentrates. Feed compositions were altered and nitrogen and phosphorus excretions were decreased by the changes of penalties, in spite of the small change in the replacement price of food by-products. Both nitrogen and phosphorus penalties greatly reduced the nitrogen and phosphorus excretions, indicating that nitrogen and phosphorus penalty coefficients should be introduced together in the objective function in order to reduce both excretions efficiently. [Copyright &y& Elsevier]

Abstract: The salmon farming industry has been criticised for being a net consumer of marine resources, in the form of fishmeals (FMs) and fish oils (FOs) used in feeds. Despite the efforts made to replace FM and FO with alternatives, such as vegetable proteins and oils, the balance is still generally negative, with calculated fish in–fish out (FIFO) values often being over 4. This paper reports on a FM and FO replacement study, with maximum 20 and minimum 10% FM inclusion in high-energy, extruded salmon feeds, and in which 50% of the feed oil was of vegetable origin (rapeseed). Further, half of the dietary FO was oil reclaimed from fish processing waste (herring offal silage oil), the other half being pristine FO (blend of herring and anchoveta oils). Growth and feed utilisation were assessed in a 9month trial, during which fish weight increased from ca. 1.2kg to ca. 4.6kg. There were no significant differences between feed treatments with respect to growth, feed utilisation and mortality, and replacement of FM with vegetable proteins did not compromise the bioavailability of feed nutrients. Salmon given the feed with the highest level of fishmeal replacement (FM10) had a net production of fillet protein relative to feed input in the form of protein derived from FM, indicating that FM supply is not a major factor that would impose serious limits on the quantity and efficiency of production. The inclusion of FO as 50% of the feed oils ensured that the salmon fillets contained levels of n-3 highly-unsaturated fatty acids (n-3 HUFAs) that would be considered adequate from a consumer perspective (at least 1.5g n-3 HUFAs per 100g fillet) and the ratio of n-6 to n-3 fatty acids (ca. 0.65) was also favourable from a human health point of view. There was net consumption of marine fish resources when assessed as FIFO calculated on the basis of the amounts of fish required to produce all FOs (FIFO 3.03–3.59) and on fish needed to produce pristine FOs included in the feeds (FIFO 1.53–1.83). Calculations based upon nutrient ratios gave positive outcomes, and salmon in all treatments deposited more fillet fat than the amount of pristine FO consumed. It is concluded that supplies of FOs impose greater limitations on the formulation of salmon feeds than do supplies of FMs. The results of the study also indicate that increased use of fish processing by-products has the potential to reduce some of the predicted short-fall in FOs resulting from reductions in the amounts of small, pelagic marine fish species rendered directly for the production of FMs and FOs. [Copyright &y& Elsevier]

Abstract: A multi-objective optimization method based on the traditional least-cost formulation program was developed to reduce both feed cost and total phosphorus (P) content in pig feeds. The objective function of the proposed method comprises a traditional economic term and a term that assigns a cost (β) to the excess and unavailable P (EUP) in the diet, the latter estimated by the difference between P requirements and available P supplied by the diet. To evaluate this method, feeds for growing (20–65 kg live weight) and finishing pigs (65–105 kg) formulated with two balanced protein levels (90 and 130 g/kg) and two available phosphorus levels (3.2 and 2.6 g/kg) were evaluated in two economic contexts (France and Quebec) over a 12-month period (June 2002–May 2003). Microbial phytase was added to the feeds at rates of 0, 250, 500 and 750 phytase units. All feed formulas contained the required available P and other nutrients. The increase in β reduced the total P and EUP in feed formulas. During the period studied, EUP decreased by 5% or more for an increase in feed cost of about 1.5% in France and 1% in Quebec. For some months however, the economically optimal solution was close to a solution that produces substantially less EUP at slightly higher cost. For example, in nearly half of the months, a reduction of 10% or more was achieved in Quebec for the same 1% increase in ingredient cost. The reduction in EUP with increasing β occurred independently of the addition of microbial phytase. The combined effect of microbial phytase incorporation and the proposed feed formulation method on EUP reduction is almost additive. Thus, the combined use of these two techniques can promote the sustainability of the swine industry by contributing to the reduction of P excretion in swine operations with small increases in feeding cost. The proposed method can be applied to minerals other than P or to other livestock production systems in which mineral excretion can be estimated from feed composition. [Copyright &y& Elsevier]

Abstract: There is a need to develop new methods for formulating optimal feeds for farmed fish, and for making explicit assessments of the criteria by which the success of a formulation may be judged. We show how a combination of mixture design theory and state-space models of nutrition (the Geometric Framework, GF) can be used to derive a 5-step protocol for multi-criterion diet optimisation. Step 1 involves selecting the focal nutritional axes for modelling; step 2 uses mixture theory to choose an optimal selection of experimental diets to test in experiments; step 3 entails using GF to plot and interpret intake and growth arrays; step 4 involves plotting response variables onto intake arrays, and step 5 uses multi-criterion optimisation to combine and weigh several relevant response variables. We illustrate the approach by re-analysing data from dietary studies on European whitefish. [Copyright &y& Elsevier]

Applications of a rapid appraisal approach to identify locally available feed ingredients in feed formulation, production, and socio-economics of Nile tilapia aquaculture in Bangladesh are discussed. Three diets of 35%, 30%, and 25% crude protein were formulated using locally available ingredients, and their essential amino acid profiles were assessed for Nile tilapia. Six production scenarios were constructed using these diets and two culture periods of 100 and 150 days were considered. The production scenarios with 35% protein yielded the highest productivity and profitability over the 150-day culture period followed by the 30% protein scenario. Identification of locally available ingredients and their application in small-scale Nile tilapia aquaculture may lead to: (1) increased availability of inexpensive sources of fish production for poor people; (2) increased fish consumption; (3) increased self employment and involvement of women in productive activities; and (4) increased household income to reduce poverty. [ABSTRACT FROM AUTHOR]

A 309 days feeding experiment was carried out on gilthead sea bream fingerlings (initial weight 14.7±4.4 g) to evaluate effects of substitution of fish oil with soybean oil in diets on growth and sensory characteristics and muscle fatty acid composition. Duplicate groups of fish were hand fed with four isoenergetic and isonitrogenous diets (46% protein, 14% lipid and 22 MJ kg−1) in which 0%, 24%, 48% or 72% of the fish oil was replaced by soybean oil. Fish fed diet 72% reached a lower final weight (324 g) than fish fed diets 0%, 24% and 48% (349, 343 and 338 g respectively). Feed intake, protein efficiency ratio, body composition and economic profitability were not influenced by the amount of soybean oil in the diets, but muscle fatty acid composition differed with diets. Panellists observed significant sensory differences between fish fed diet 0% and diet 72%. These results verified the possibility of feeding sea bream until they reached commercial weight with a 48% dietary substitution of fish oil for soybean oil. [ABSTRACT FROM AUTHOR]

The value of defatted soybean meal as a protein source for sea bream fingerlings (15.2±4.4 g on average) growing to market size (300–350 g) was evaluated by feeding extruded isonitrogenous and isoenergetic diets (46% protein and 22 MJ kg−1) containing 20%, 30%, 40% and 50% soybean meal considering two phases. On day 87, the fish weight ranged between 66 and 81 g. The specific growth rate (SGR) of sea bream fed 50% soybean was lower (1.73% day−1) than that of fish fed 20% (1.87% day−1) and 30% (1.93% day−1), but the food conversion ratio (FCR) was not significantly affected, and a quadratic significant trend was observed for the feed intake (FI) in relation to the dietary soybean level. At the end of the second phase on day 309, fish weight was between 303 and 349 g, but SGR and FCR were similar for all diets, and ranged between 0.64 and 0.69% day−1, and 1.95 and 2.10% day−1 respectively. The final biometric parameters were not affected by the diets, although the levels of some free amino acids in the muscle were affected. Sensory differences were detected by panellists in fish fed diet 20% as compared those fed diet 50%, which had a less marine flavour and was less juicy. The global growth results suggest the possibility of feeding sea bream weighing less than 80 g with 30% soybean meal, and for fish weighing more than 80 g, a 50% dietary soybean meal can be used until the fish reach commercial weight, with no negative effects on growth or feed efficiency. Nevertheless, when sensory analysis and economic aspects are considered, the maximum inclusion level of soybean was 20–22%. [ABSTRACT FROM AUTHOR]

Determination of the optimal protein-to-energy ratio of fish feed is used as an example of how to improve the efficiency of experimental designs for feed formulation research. Studying one variable at a time is inefficient and lacks information on interactions between feed components. Even sound designs, such as full factorials, may fail in feed formulation studies because often two or more factors are implicitly confounded. A class of response surface methodology, namely designs for mixture experiments, is well suited for feed formulation problems and ensures that results are readily applicable to the feed industry. Combined with some criteria for searching the optimal runs for the experiment, mixture designs can improve the efficacy of resource use and diminish risks of inference and decision-making in fish feed research and development. [ABSTRACT FROM AUTHOR]

Two feed mixture trials were conducted on the European whitefish. For both trials, nine diets with varying levels of fish meal (FM), fish oil (FO) and cornstarch (CS), and fixed levels of wheat meal and vitamin–mineral premix (12%), were formulated according to d-optimality criteria assuming a quadratic response surface. In the two trials, the proportions of the ingredients were, respectively: 38–86% and 43–85% for FM, 2–22% and 0–30% for FO, and 0–33% and 0–15% for CS. The extruded diets were fed to satiation for 72 and 85 days in a flow-through, freshwater system at 15 °C. Optimal allocation of replicates among 25 and 29 tanks was based on d-optimality criteria. The response surfaces were modelled as quadratic and super-cubic polynomials specific for mixture designs. The data from the trials were combined for the final analysis, which included the experiment as a random effect. Fish growth increased with increasing FM content up to 66.3% FM (16.7% FO and 5.0% CS). Protein growth peaked at a somewhat higher FM content of 72.0% (10.2% FO, 5.9% CS), and lipid deposition rate at the highest studied FO content (53.1% FM, 30.0% FO and 4.9% CS). Feed efficiency improved with decreasing CS content and the highest value was obtained with the mixture containing 58.0% FM, 30.0% FO and 0.0% CS. Protein retention efficiency was improved with decreasing FM content and peaked at a mixture of 50.2% FM, 30.0% FO and 7.8% CS. The diet inducing 95% of the maximum growth with the minimum FM content comprised of 51.2% FM, 30.0% FO and 6.8% CS. Based on the data from these two experiments, an area of optimal diet formulation can be assessed by graphically superimposing isobars of 95% growth, feed efficiency and dietary protein utilisation responses. This optimal composition for the European whitefish appears to be in the range of 53–61% FM, 24–30% FO and 0–7% CS together with the 12% wheat meal and vitamin–mineral premix. However, this optimisation is based on round weight and because high dietary lipid levels induced high lipid deposition rates, the practical optimum for dressed weight would be at a somewhat lower FO level. Mixture experimentation proved to be an efficient method to rapidly screen European whitefish diets for nutritional optimisation. [Copyright &y& Elsevier]