Hermetia Illucens Meal as Fish Meal Replacement for Rainbow Trout PDF

Wageningen Academic Journal of Insects as Food and Feed, 2017; 3(3): 165-175 P u b l i s h e r s Hermetia illucens meal as fish meal replace...

Wageningen Academic Journal of Insects as Food and Feed, 2017; 3(3): 165-175 P u b l i s h e r s Hermetia illucens meal as fish meal replacement for rainbow trout on farm T. Stadtlander1*, A. Stamer1, A. Buser1,2, J. Wohlfahrt1, F. Leiber1 and C. Sandrock1 1Research Institute of Organic Agriculture, Ackerstr. 113, 5070 Frick, Switzerland; 2ETH Zurich, Institute of Agricultural Sciences, Animal Nutrition, Universitaetstrasse 2, 8092 Zurich, Switzerland; [email protected] Received: 14 November 2016 / Accepted: 6 May 2017 © 2017 Wageningen Academic Publishers OPEN ACCESS RESEARCH ARTICLE Abstract In a 7-week on-farm feeding trial rainbow trout (Oncorhynchus mykiss) were provided with a diet containing 28% mechanically de-fatted insect meal prepared from larvae of the black soldier fly, Hermetia illucens (HIM) and compared to a control that received a certified organic and fishmeal based diet. In the test diet insect meal replaced almost 50% of the fishmeal. The whole experiment was conducted under practical conditions on an organically certified rainbow trout farm in Switzerland. Fish of initially 66.5±2.3 g body weight were grown to 125±4.5 g and assessed for their growth performance, as well as analysed for their proximate composition, feed conversion ratio, fatty acid contents and organoleptic properties. Improved lipid utilisation and decreased protein utilisation were observed in fish fed the HIM diet. Furthermore, in a controlled degustation no differences except a slightly darker coloration of fish fed HIM were observed. The experiment demonstrated that substantial replacement of fishmeal by insect meal is possible without compromising growth, feed conversion and product quality. However, the decreased protein utilisation efficiency in HIM fed fish might lower production efficiency when applied over a whole production cycle and not only over 7 weeks. Keywords: insect meal, fishmeal replacement, growth performance, feed conversion, organoleptic properties 1. Introduction according to all organic and almost all sustainability directives or standards, such as the standard for organic Production of fish in aquaculture is increasingly contributing aquaculture of the European Union (EC, 2009), Naturland to global food fish supply. Already in 2006 almost every (Naturland, 2014), Soil Association (Soil Association, 2016), second food fish was aquaculture produced (Cressy, 2009). Bio Suisse (2015) and the Aquaculture Stewardship Council The global finfish production increased by 90% during the (ASC, 2012). Instead, fishmeal produced from trimmings of last decade (2004-2014) (FAO, 2016). Thus, demands for food fish or from fish caught under a sustainability scheme high quality and protein rich feed ingredients is growing, (e.g. Marine Stewardship Council) needs to be used which, too. This is especially the case for organic aquaculture as all in case of fishmeal from trimmings, contains relatively more feed ingredients must be organically or sustainably certified, Phosphorous than other fishmeal. As a consequence of the thus strongly limiting the availability of feed ingredients and limited fishmeal resources, plant derived protein sources influencing the prices. Traditionally, fishmeal is the most have been increasingly utilised for aquaculture feeds in the important protein source for aqua feeds but fishmeal supply last decade, with soy beans and soy protein concentrate, from targeted fishery is limited to around 5.5-6.5 million wheat and wheat gluten, corn, canola, cottonseed, peas/ metric tons annually (Hardy, 2010) resulting in continuously lupines and barley being the most important alternatives decreasing fishmeal levels in fish feeds (Deutsch et al., (Naylor et al., 2009; Olsen and Hasan, 2012). Still, in terms 2007; Naylor et al., 2009). Furthermore, some of the fish of land use efficiency, the direct competition between plants currently used for fishmeal production could directly be being produced as animal feed, versus plants produced consumed by humans (Fréon et al., 2014). For organic as human food remains an unsolved issue (Cassidy et al., aquaculture the situation is even more complicated as the 2013; Schader et al., 2015). implementation of conventionally produced fishmeal, i.e. fishmeal from targeted reduction fishery, is prohibited Downloaded from Brill.com 08/07/2024 08:04:31PM ISSN 2352-4588 online, DOI 10.3920/JIFF2016.0056165 via Open Access. This content is licensed under the CC-BY-NC-ND license..https://creativecommons.org/licenses/by-nc-nd/4.0/ T. Stadtlander et al. Besides plant based protein sources several animal based with vegetarian preconsumer food waste supplied by feedstuffs are readily available and utilised too (Naylor convenience industry. The feeding substrate for H. illucens et al., 2009). The interest in insects as feed for a variety larvae was basically composed of pasta, spent brewer grains of livestock species is strongly increasing (Barroso et al., and fruit and vegetable leftovers. When the majority of the 2014; Henry et al., 2015; Makkar et al., 2014; Sánchez- larvae reached the prepupal stage, they were separated from Muros et al., 2014). One particularly promising candidate debris, killed by freezing at -20 °C and stored frozen until insect species is the black soldier fly, Hermetia illucens, further processing. The prepupae were washed in water and because it can be employed to convert food waste material cleaned from debris, oven dried for 24-34 hours at 60 °C and or manure into high quality insect protein highly suitable coarsely ground. Afterwards the insects were mechanically to be implemented in animal feed (Sheppard et al., 1994). defatted with a small scale commercial oil press (KK 20 F It is native to Central and Latin America and large parts of Universal; Screw Press, Reut, Germany) and the press cake the USA, yet secondarily established in virtually all (sub-) was milled in order to obtain a homogenous meal. The tropical regions worldwide (Sheppard et al., 1994). The defatted HIM was stored frozen until fish feed production. protein and lipid content of H. illucens meal (HIM) is highly variable; based on dry matter, protein and lipid contents Experimental diets reported for de-fatted HIM were 47.2 and 11.8% (Kroeckel et al., 2012) and 51.8 and 14.8%, respectively (Cullere et Two different diets, one commercial and one experimental al., 2016), whereas protein and lipid content reported for diet, were applied. Manufacturing of both diets using full-fat HIM were 36.2 and 18.0% (Barroso et al., 2014). Its extrusion-cooking in a commercial-scale extruder was potential as a valuable feed ingredient has been reported for commissioned to Hofmann Nutrition AG (Bützberg, several livestock species, such as poultry (cockerels, Hale, Switzerland). The standard organic grow-out feed ‘Natura 1973; layer hens, Maurer et al., 2016; broilers, Leiber et al., Trout’ (certified under the Bio Suisse regulation) served as 2017; Cullere et al., 2016), pigs (Newton et al., 1977) and a control diet (diet C) and contained the ingredients fishmeal, number of commercially important cultured fish species wheat flour, soy meal, blood meal, vitamin and mineral like Atlantic salmon (Salmo salar, Lock et al., 2015), channel premixes and the immunostimulant Immuguard®. The same catfish (Ictalurus punctatus) and blue tilapia (Oreochromis ingredients with the same proportions have been used for aureus, Bondari and Sheppard, 1981, 1987), Nile tilapia, the H. illucens meal diet (diet HIM) with the only difference (Oreochromis niloticus, Hem et al., 2008; Webster et al., that 46% of the fishmeal has been substituted by HIM, 2015), rainbow trout (Oncorhynchus mykiss, Gasco et al., which in turn corresponded to 28.1% of the final diet. The 2015; Sealey et al., 2011; St-Hilaire et al., 2007) and turbot pellet size was 3 mm; the proximate composition of both (Psetta maxima, Kroeckel et al., 2012). diets is presented in Table 1. The formulation details are confidential property of Hofmann Nutrition AG and have The rainbow trout is the most important freshwater not been cleared for publication. The digestible energy was aquaculture species in central Europe with a total estimated by caloric equivalents of 16.7 MJ/kg for nitrogen production volume of 294,000 metric tons (mt) in 2014 free extracts (NFE), 33.5 MJ/kg for crude lipids (CL) and (FAO, 2016). In Switzerland the production volume was 19.6 MJ/kg for crude protein (CP) according to Brett and 1,100 mt out of 1,393 mt total volume in 2014, thus, making it by far the most important cultured species of which around 30% are organically certified (FAO, 2016; Table 1. Proximate composition of the control (C) and the Stadtlander and Gerber, 2014). Hermetia illucens meal (HIM) diets. Values derived from one pooled sample per feed type. The aim of this experiment was to evaluate de-fatted HIM as replacement of approximately half of the fishmeal in Proximate analyses Diet C Diet HIM extrusion cooked and organically certified trout feed. In a seven week experiment the growth performance, feed and Crude protein (g/kg DM) 457 491 (477)1 nutrient conversion and organoleptic properties of rainbow Crude lipids (g/kg DM) 151 126 trout fed with either a commercial control feed or a feed Ash (g/kg DM) 134 126 with high fishmeal replacement by HIM were compared. Crude fibre (g/kg DM) 13 44 Nitrogen free extract (g/kg DM) 189 164 2. Materials and methods Digestible energy (MJ/kg DM) 17.2 17.0 (16.3)1 DP:DE ratio (g/MJ)2 23.5 25.9 (25.5)1 Production of insect meal 1 Crude protein corrected for crude fibre (presumably corresponding to Freshly emerged H. illucens larvae were fed with chicken chitin in the HIM; see Lovell et al., 1968). feed (Demeter layer hen crumble) for 10 days until 2 DP:DE = estimated digestible protein to digestible energy ratio in reaching the second larval stage. Later on they were fed g digestible protein per MJ digestible energy. Downloaded from Brill.com 08/07/2024 08:04:31PM 166 Journal via Open Access. This content is of Insectsunder licensed as Food the and Feed 3(3) CC-BY-NC-ND license..https://creativecommons.org/licenses/by-nc-nd/4.0/  Hermetia illucens meal in diets for rainbow trout on farm Groves (1979). The digestibility of CP in both diets was Feed conversion ratio (FCR) = total dry feed intake (g) / (final body estimated to be 83.1% (based upon an average gross energy weight (g) – initial body weight (g)) content in CP of 23.6 MJ/kg (NRC, 2011) and the digestible energy content of 19.6 MJ/kg (Brett and Groves, 1979)). Protein efficiency ratio (PER) = (final body weight (g) – initial body weight (g)) / total protein intake (g) × 100 Experimental setup and fish Protein productive value (PPV; %) = (final fish protein content (g) – The experiment was conducted on an organically certified initial fish protein content (g)) / total protein intake (g) × 100 trout farm in Switzerland under practice conditions. The farm is designed as water re-use system comprising of Lipid efficiency ratio (LER; %) = (final body weight (g) – initial body three channels running in a circle with seven 65.1 m3 weight (g)) / total lipid intake (g) × 100 compartments per side (14 per channel), a fluid bed bio filter at each end and a drum filter at the distal end. Lipid productive value (LPV) = (final fish lipid content (g) – initial The water in each channel is flowing circularly through fish lipid content (g)) / total lipid intake (g) all compartments and the respective water flow rate is approximately 200 l/s. Around 10% of the total water Viscerosomatic index (VSI; %) = viscera weight (g) / final body weight volume was exchanged per day. For the experiment the (g) × 100 two compartments directly downstream of one of the bio filters were used. This setup was replicated in each of the Hepatosomatic index (HSI; %) = liver weight (g) / final body mass three channels resulting in three independent replicates (g) × 100 for each treatment. At the beginning of the experiment each compartment was stocked with a total of 191.3 kg Water quality rainbow trout with an average individual weight of 66.5±2.3 g (mean ± standard deviation), corresponding to an initial Oxygen content, pH and temperature of the water were stocking density of 2.91 kg per m3 and 2,874±100 fish in measured daily with a hand-held Hach HQ 40d multi each compartment, respectively. (Hach Company, Loveland, CO, USA). Once a week ammonia-N, nitrite-N and nitrate-N were measured The fish were hand fed four times per day according to the spectrophotometrically with test-kits from Hach Company water temperature and their biomass under a restrictive and calculated as ammonia, nitrite and nitrate. scheme adapted from the feed manufacturer (Table 2). The water temperature was ambient and ranged between Sampling 8.7 and 12.1 °C. Every second week around 100 fish were weighed in each compartment to adjust feeding rations. Prior to each sampling occasion, all fish were starved for When the water was too turbid, for instance after heavy one day in order to ensure that digestive tracts have been rainfall, no feed was provided (this happened on 2 days). cleared. Before the experimental feeding started, 10 fish from the initial stock were randomly sampled as a reference In order to evaluate the growth performance and nutrient for proximate composition. At the end of the 7-week feeding utilisation the following parameters were calculated: trial, 10 fish per replicate (30 per treatment) were randomly sampled for determination of proximate composition and Percent weight gain (PWG; %) = (final body weight (g) – initial body morphometric characteristics. Collections of morphometric weight (g)) / initial body weight (g) × 100 data included body weight and fork length, and the visceral fat coverage estimated on a scale of 0 to 4, corresponding Specific growth rate (SGR; %/day) = (ln final body weight (g) – to 0-100% coverage, respectively. Further, the viscera were ln initial body weight (g)) / days of experiment × 100 dissected and weighed before dissecting and weighing the liver. Afterwards all viscera, including the liver, were frozen together with the rest of the respective fish until further analysis. All fish intended for morphometric and proximate composition analysis were euthanized using 150 mg/l MS- Table 2. Feeding table adapted from the feed manufacturer 222 buffered with 300 mg/l sodiumhydrogencarbonate, showing daily feeding allowance (as % of body weight per day). and then frozen at -18 °C until further analysis. Also at the end of the experiment, another 10 fish per replicate were Weight of fish (g) Water temperature (°C) starved for five days, electrically stunned, exsanguinated and kept on crushed ice for the organoleptic test the next day. 8 9 10 11 12 50-100 1.28 1.36 1.44 1.52 1.59 100-200 1.13 1.20 1.27 1.34 1.40 Downloaded from Brill.com 08/07/2024 08:04:31PM Journal of Insects as Food and Feed 3(3) 167 via Open Access. This content is licensed under the CC-BY-NC-ND license..https://creativecommons.org/licenses/by-nc-nd/4.0/ T. Stadtlander et al. Chemical analysis normal distribution or homogeneity of variance were not met non-parametric Mann-Whitney-U tests were applied. For chemical analyses, the fish sampled initially before Alpha-levels were set to 0.05. the feeding trial started and at the end of the experiment were homogenised and then pooled for each replicate per 3. Results treatment, resulting in one initial sample and six samples taken at the end of the experiment. For homogenisation, Chemical analyses revealed differences in the proximate they were cut into small pieces while still frozen, autoclaved composition of the two different feeds. As compared to for 15 minutes at 121 °C and turraxed with an Ultra- diet C, diet HIM contained higher levels of CP and CF and Turrax T25 (IKA-Labortechnik, Staufen, Germany). The lower levels of CL and CA (Table 1). The AA profiles of the homogenate was frozen again and lyophilised subsequently diets and the requirements of the essential AA or rainbow using a model Beta 1-16 (Christ, Osterode am Harz, trout is presented in Table 3. Germany) in order to determine the water contents of each sample before they were finely ground and subjected Diet C was deficient in threonine and isoleucine, diet to further analyses. For amino (AA) and fatty acid (FA) HIM was deficient in methionine and both diets were determination, aliquots of the three replicated samples per almost equally deficient in lysine (Table 3). The fatty acid treatment were again pooled resulting in one sample per profiles of both diets are presented in Table 4. Diet HIM treatment. Feed pellets of both feeds were ground into a had a considerably higher overall level of saturated fatty fine powder prior to analysis. acids (SFA) and a lower level of unsaturated fatty acids (UFA) in comparison to diet C. This is also reflected in Chemical analyses of CP, CL, crude fibre (CF) and ash the ratio of UFA to SFA which was considerably higher (CA) was conducted for fish and feed samples according in diet C compared to diet HIM. The main differences in to standards defined by the Association of German UFA content are caused by oleic acid, eicosaenoic acid Agricultural and Analytic Research Institutes (VDLUFA, and erucic acid, but also the level of the important poly- 2017). NFE has been calculated by difference (100 – CP + CL + CA + CF). AA and FA determination have been conducted by chromatographical methods according to Table 3. Whole amino acid profiles of the experimental diets standard methods of the German Society for Fat Science (control; C, and Hermetia illucens meal; HIM) (g/100 g DM) and (DGF, 2015). The FA concentrations are presented as fatty the requirements of essential amino acids for rainbow trout acid methyl esters. (g/100 g DM, NRC, 2011). Dietary amino acid concentrations not reaching the requirements are shown in bold. Values derived Organoleptic test from pooled samples of the three replicates per treatment. For the organoleptic test the fish were filleted, the fillets cut Amino acid Diet C Diet HIM Requirements1 into three equally large pieces, wrapped in aluminium-foil and steam-cooked without pressure for 8-10 minutes at Aspartic acid 2.46 2.80 100 °C. The organoleptic test was conducted according to Threonine 1.03 1.17 1.1 DIN EN ISO 5495. Fifteen untrained panellists were offered Serine 0.96 1.21 double blind testing samples of the filet for differences Glutamic acid 3.21 3.57 in odour, colour, texture and taste, each in 5 (texture in Proline 1.71 1.78 6) different traits. The panellists then rated the different Glycine 1.99 2.34 characteristics on a scale between 0 (does not apply) to 9 Alanine 1.96 2.46 (applies fully). Cysteine 0.30 0.33 Valine 1.50 1.78 1.2 Statistical analysis Methionine 0.70 0.66 0.7 Methionine + cysteine 1.00 0.99 1.1 All data are presented as mean ± standard deviation Isoleucine 1.01 1.17 1.1 (n=3) if not indicated otherwise. Statistical analyses were Leucine 2.23 2.36 1.5 performed using IBM SPSS vers. 21 (IBM Corporation, Tyrosine 0.77 1.18 Armonk, NY, USA). Normal distribution of the data was Phenylalanine 1.22 1.35 0.9 assessed using Kolmogorov-Smirnov and homogeneity Phenylalanine + tyrosine 1.99 2.53 1.8 of variance was assessed using Levene tests. In case of Histidine 0.96 1.32 0.8 normal distribution and homogeneity of variance, treatment Lysine 1.94 1.99 2.4 means of the C and HIM fed fish were compared using Arginine 1.50 1.66 1.5 t-tests with compartment as individual unit and three replicates per treatment, accordingly. In case criteria of 1 Requirements according to NRC (2011). Downloaded from Brill.com 08/07/2024 08:04:31PM 168 Journal via Open Access. This content is of Insectsunder licensed as Food the and Feed 3(3) CC-BY-NC-ND license..https://creativecommons.org/licenses/by-nc-nd/4.0/  Hermetia illucens meal in diets for rainbow trout on farm unsaturated fatty acids (PUFA) arachidonic acid (ARA), Table 5. Growth and nutrient utilisation of fish fed with either eicosapentaenoic acid (EPA) and docosahexaenoic acid control (C) or Hermetia (HIM) diets (data = mean ± standard (DHA) were reduced by one third in diet HIM compared deviation; n=3). to diet C. The SFA lauric acid was only present in diet HIM and contributed considerably to the low UFA:SFA ratio in Parameter1 C fed fish HIM fed fish2 diet HIM (Table 4). Initial body mass (g) 67.0±2.5 66.2±1.9 Mortality, final body weight, growth (relative weight Final body mass (g) 125.3±4.8 125.5±4.4 gain and specific growth rate), feed conversion, viscero- PWG (%) 87.8±1.0 89.6±1.7 and hepatosomatic indices and intraperitoneal fat were SGR (%/day) 1.43±0.05 1.45±0.05 comparable for fish of both groups (Table 5). FCR 0.80±0.07 0.81±0.04 PER 2.77±0.30 2.51±0.12* Protein utilisation, however, was significantly higher, even PPV (%) 60.6±6.6 50.9±1.8* (52.4±1.8*)3 when corrected for assumed chitin content, in fish fed diet C LER 8.39±0.90 9.77±0.47* compared to fish fed diet HIM, as indicated by PER and PPV LPV (%) 47.5±7.3 60.2±4.5* (Table 5). Contrary to the protein utilisation, the apparent VSI (%) 10.1±0.8 10.5±0.2 lipid utilisation (LER and LPV, Table 5) was significantly HSI (%) 1.36±0.10 1.40±0.03 improved in fish fed diet HIM compared to fish fed diet C. Mortality (%) 0.15±0.07 0.22±0.07 Carcass composition revealed no significant differences in Intraperitoneal fat 1.40±0.26 1.43±0.15 protein, lipid and ash content between treatments (Table 6). 1 FCR = feed conversion ratio; HSI = hepatosomatic index; LER = lipid efficiency ratio; LPV = lipid productive value; PER = protein efficiency ratio; PPV = protein productive value; PWG = percentage weight gain; SGR = specific growth rate; Table 4. Fatty acid profiles of the two experimental diets VSI = viscerosomatic index. (control; C, and Hermetia illucens meal; HIM) (g/100 g fatty acid methyl esters). Values derived from pooled samples of 2* = significant difference (P