IMPROVED FEED FOR SHRIMP FARMING CONTAINING HERMETIA ILLUCENS MEAL

Abstract

The invention relates to the field of decapod feed comprising animal meal. More particularly, it concerns an improved feed for shrimp farming which allows for better yields in shrimp and which comprises meal from the larvae of the black soldier fly of the species Hermetia llucens.

Description

Title of the invention: IMPROVED FEED FOR SHRIMP FARMING COMPRISING DEHERMETIA ILLUCENS FLOUR

[0001] The invention relates to the field of decapod feed comprising insect meal. More particularly, it relates to an improved feed for shrimp farming comprising meal from the larvae of the black soldier fly species Hermetia illucens. It improves weight gain, growth rate, feed conversion ratio, and resistance to infection in shrimp. FIELD OF INVENTION

[0002] Shrimp farming is a branch of aquaculture whose commercial production is constantly increasing, driven by strong demand from territories such as the United States, Japan, and Western Europe. The vast majority of farmed shrimp belong to the Penaeidae family, and two species, the white-legged shrimp (Litopenaeus vannamei) and the giant tiger prawn (Penaeus monodon), account for nearly 80% of all farmed shrimp. In order to meet the increasing global demand, manufacturers must produce larger volumes of shrimp, which represents significant farming costs, particularly for feeding these animals throughout their rearing cycle. Shrimp feed is generally composed of fishmeal.In addition to being expensive, fishmeal has a significant environmental footprint, as it is produced from finite resources and the volumes required to supply the shrimp and aquaculture industries in general are considerable. Indeed, today, the consumption of large volumes of fishmeal by shrimp is essential for them to reach optimal sizes suitable for human consumption.

[0003] This industrial monoculture is highly susceptible to disease. Diseases have caused several large-scale epidemics in certain farmed shrimp populations. Common diseases include severe hepatopancreatic necrosis syndrome and white spot syndrome.

[0004] The Pacific white shrimp (Litopenaeus vannamei) is the most produced shrimp species in the world, with production volumes exceeding 4.1 million metric tons in 2016 (FAO 2018). To support the growth of the Pacific white shrimp industry, it is necessary to find high-performing feed ingredients that can be produced sustainably and to improve efficiency. production systems to supply larger volumes while putting less pressure on natural resources.

[0005] Protecting both the long-term potential of the industry and preserving natural resources is a growing challenge, not only in the context of L. vannamei production, but also in all modern food production systems.

[0006] Plant-based ingredients have therefore become commonly used in aquaculture feed formulations over the past few decades (Barrows et al. 2007, Gatlin et al. 2007, Oliva-Teles et al. 2015). They have been used successfully to replace some of the fishmeal in these feed formulas. However, plant proteins have certain nutritional limitations for aquaculture feeds: the presence of antinutritional factors, high levels of fiber and non-starch polysaccharides, inadequate fatty acids, unbalanced essential amino acid profiles, and reduced digestibility and palatability. Furthermore, a complete substitution of fishmeal with plant-based ingredients can lead to additional pressure on essential agricultural resources and the environment (e.g., deforestation related to soybean cultivation).Therefore, research efforts have been deployed to find more effective substitute ingredients.

[0007] As a result, manufacturers are turning to new alternatives to fishmeal. An increasing number of feeds, particularly in fish farming, are incorporating insect meal. Indeed, insect meal production is more environmentally friendly and can be based on vertical farming, which requires less land compared to other farming methods.

[0008] Prior art reports examples of the use of insect meal as a substitute for fishmeal. Patent CN108576485 discloses a feed composed of Hermetia illucens insect meal for feeding fish.

[0009] However, it is generally known from the prior art that insect-based feeds, and in particular Hermetia illucens, when substituted for fishmeal, do not provide adequate weight gain and final weight compared to fishmeal. In this regard, the article "Evaluation of Black Soldier Fly (Hermetia illucens) larvae meal as partial or total replacement of marine fish meal in practical diets for pacifie white shrimp (Litopenaeus vannamei)" (Cummins et al. 2017) describes compositions including HI meal obtained by alcoholic extraction, combined with soybean meal. In these trials, the inclusion rate of HI meal ranged from 7% to 36%. No significant difference in growth performance or survival was observed in shrimp whose diet included HI meal. This article concludes that the growth of shrimp fed with a diet including fishmeal and HI meal has a lower yield than shrimp fed with fishmeal alone.

[0010] In view of current and future food challenges, aquaculture is a promising solution on a global scale; manufacturers are looking for solutions to improve the yield of shrimp farms. Description of the invention

[0011] The inventors have developed a feed for shrimp farming comprising a portion of Hermetia llucens meal in association with fishmeal; this feed allows for an improvement in the yield of shrimp farms compared to an equivalent conventional feed based on fishmeal.

[0012] Thus, the present invention relates to a feed for shrimp farming allowing an improvement in farming yield comprising, instead of the 5 to 30% of fishmeal in a conventional feed, 5 to 30% of animal meal consisting of fishmeal and Hermetia illucens larvae meal, characterized in that said Hermetia illucens larvae meal represents between 30 and 60% of said animal meal.

[0013] The present invention also relates to the use of this food for improving weight gain, growth rate and feed conversion ratio and resistance to infections in shrimp. ADVANTAGES OF THE INVENTION

[0014] The inventors have developed a feed for shrimp farming comprising Hermetia illucens (HI) larvae meal, which, quite surprisingly, allows for a significantly higher yield than that observed for an equivalent feed containing fishmeal instead of HL meal. This improvement in yield is observed on several key parameters in aquaculture.

[0015] First, when this feed is used in shrimp feed, a significant improvement in growth performance is observed. Shrimp fed with this feed gain more weight and grow faster than those fed with conventional fishmeal-based feed. This improved growth rate means that the decapods reach a given weight in a shorter time, resulting in lower fixed production costs.

[0016] The use of this feed also improves the feed conversion ratio. This parameter is economically essential for controlling production costs in aquaculture, since thanks to this feed, shrimp reach the same weight with a smaller quantity of feed.

[0017] Finally, the use of a feed such as that described in this application improves the shrimp's resistance to infections during rearing. This results in a decrease in the mortality rate. In particular, the use of this feed increases resistance to viral infections, especially against the virus responsible for white spot syndrome, which is widespread in shrimp but more generally present in decapods. The use of this feed also increases resistance to bacterial infections, especially against the Vibrio bacterium responsible for acute hepatopancreatic necrosis syndrome. DETAILED DESCRIPTION OF THE INVENTION

[0018] A first object of the present invention relates to a feed for shrimp farming intended to improve farming yield, comprising 5 to 30% of animal meal made up of fish meal and Hermetia illucens larvae meal, characterized in that said Hermetia illucens larvae meal represents between 30 and 60% of said animal meal.

[0019] The term "shrimp farming feed" means any feed used in aquaculture, used as food in the diet of farmed shrimp. In the context of the invention, this refers to a feed comprising between 5% and 30% animal meal consisting of fishmeal and HI meal.

[0020] “Animal meal” means meal produced from animals, in particular marine animals such as fish and crustaceans, insects, or other animals such as poultry, alone or in mixtures. In a preferred embodiment, the animal meal includes fishmeal.

[0021] In a preferred embodiment, HI larvae meal constitutes between 40% and 60% of the animal meal. In an even more preferred embodiment, HI meal constitutes between 50% and 60% of the animal meal; this embodiment is particularly suitable for improving the infection resistance of shrimp.

[0022] “Improved shrimp farming performance” means improved weight gain, growth rate, and feed conversion ratio compared to the performance of shrimp fed with an equivalent conventional feed containing fishmeal instead of HI meal. Furthermore, the concept of performance also encompasses the fact that the feed provides better resistance to infections; by minimizing mortality within the farm, overall production is improved.

[0023] In a particular embodiment, the shrimp are chosen from the species Litopenaeus vannamei, Litopenaeus stylirostris and Penaeus monodon.

[0024] In a particular embodiment of the invention, HI flour is obtained via a mechanical preparation process, without chemical treatment or extraction. in a solvent. Such a mechanical process can be a mechanical extraction of the solid part of the previously crushed and heated larvae, followed by drying and grinding of this solid part to obtain flour.

[0025] Regardless of the process, the H. illucens larvae used for the manufacture of flour are preferably whole.

[0026] In a second object of the invention, the feed intended for shrimp farming is used to improve the yield of said shrimp farming.

[0027] Performance includes the growth performance of the shrimp which is evaluated on weight gain, growth rate and feed conversion rate, and resistance to infections.

[0028] The use of a feed according to the invention improves the weight gain and growth rate of said shrimp. Shrimp fed with the feed comprising 5 to 30% animal meal made up of fishmeal and HI meal, characterized in that Hermetia llucens (HI) larvae meal represents 30 to 60% of said animal meal, grow and fatten faster and more than shrimp fed with an equivalent feed containing fishmeal instead of HI meal.

[0029] The use of a feed according to the invention also improves the feed conversion ratio of said shrimp. Shrimp fed with the feed comprising 5 to 30% animal meal consisting of fishmeal and HI meal, characterized in that Hermetia illucens (HI) larvae meal represents 30 to 60% of said animal meal, have a greater capacity to convert feed into biomass than shrimp fed with an equivalent feed containing fishmeal instead of HI meal.

[0030] Finally, the use of a feed according to the invention improves the infection resistance of said shrimp. Shrimp fed with the feed comprising 5 to 30% animal meal made up of fishmeal and HI meal, characterized in that Hermetia llucens (HI) larvae meal represents 30 to 60% of said animal meal, are more resistant to infections than shrimp fed with a feed containing fishmeal instead of HI meal. In particular, greater resistance to viral infections such as that caused by the virus responsible for white spot syndrome is observed. The shrimp are also more resistant to bacterial infections such as severe hepatopancreatic necrosis syndrome.

[0031] The present invention will be better understood by reading the following examples, which are provided by way of illustration and should in no way be considered as limiting the scope of the present invention. DESCRIPTION OF THE FIGURES

[0032] [Fig. 1][Fig. 1]: Graphical representation of the average weight gain (%) as a function of the ingested feed. The horizontal line represents the observed weight gain compared to the control feed, whose animal meal is composed entirely of fishmeal at a rate of 30% (feed without HI meal). The diagonal line represents the positive trend observed in weight gain. The values ​​associated with the same letter do not show a significant difference between them (Fisher's test, p > 0.05).

[0033] [Fig.2] [Fig.2]: Graphical representation of the average weight gain (%) as a function of the ingested feed. The horizontal line represents the observed weight gain compared to the control feed, whose animal meal is composed entirely of fishmeal at a rate of 30% (feed without HI meal). The dashed line represents the positive trend observed in weight gain. The values ​​associated with the same letter do not show a significant difference between them (Fisher's test, p > 0.05).

[0034] [Fig.3][Fig.3]: Graphical representation of the average conversion index in function of the feed ingested. The horizontal line represents the observed feed conversion ratio compared to the control feed, in which the animal meal is entirely composed of fishmeal at a rate of 30% (feed without HI meal). The dashed line represents the observed trend in the feed conversion ratio compared to the control feed. Values ​​associated with the same letter do not show significant differences (Fisher's test, p > 0.05).

[0035] [Fig.4][Fig.4]: Graphical representation of weight gain (g), growth rate specific (% / day) and average feed conversion ratio as a function of the feed ingested. CTRL corresponds to the control feed in which the animal meal is entirely composed of fishmeal at a level of 15%. A, B and C correspond to the improved feeds in which HI meal represents 30%, 50% and 70% respectively of the animal meal made up of fishmeal and HL meal. The values ​​associated with the same letter do not show a significant difference between them (Fisher's test, p > 0.05).

[0036] [Fig.5] [Fig.5]: Graphical representation of the results collected during The experiment was conducted with the pathogen AHPNS. "Mock" corresponds to the disease-negative control group, and "CTRL" to the disease-positive control group. Shrimp in both groups were fed the control diet, in which the animal meal was composed entirely of fishmeal at a rate of 15%. A, B, and C correspond to the improved diets in which HI meal represents 30%, 50%, and 70%, respectively, of the animal meal, which is composed of fishmeal and HL meal. The values ​​associated with the same letter did not show any significant difference between them (Fisher's exact test, p > 0.05).

[0037] [Fig.6] [Fig.6]: Graphical representation of the results collected during The experiment was conducted with the WSSV pathogen. "Mock" corresponds to the disease-negative control group, and "CTRL" to the disease-positive control group. Shrimp in both groups were fed the control diet, in which the animal meal was composed entirely of fishmeal at a rate of 15%. A, B, and C correspond to the improved diets in which HI meal represents 30%, 50%, and 70%, respectively, of the animal meal, which is composed of fishmeal and HL meal. The values ​​associated with the same letter did not show significant differences (Fisher's exact test, p > 0.05). EXAMPLES

[0038] EXAMPLE 1: Improvement of the yield of a L. stylirostris shrimp farm by the introduction of an improved feed comprising Hermetia illucens meal

[0039] Materials and methods

[0040]

[0041] Experimental Conditions This experiment was conducted on shrimp of the species L. stylirostris. The experimental area consisted of 40 50L tanks and their water supply tanks. A 100% hourly seawater exchange rate was applied to all tanks. The quality of the seawater supply was ensured by a mechanical filtration system. In addition, water temperature control was achieved using a chiller and / or heating elements in the tanks. Only salinity (natural salinity approximately 35‰) and photoperiod were not continuously monitored. This experiment was carried out with animals from a support tank (Ifremer / LEAD-NC) with an initial average weight of 5.83 ± 1.23 g and a stocking density of 7 individuals per tank. The transfer was carried out 7 days before the start of the study in order to acclimate the animals to the experimental conditions.During this period, the animals were individually weighed and tagged to establish their initial weights and allow for identification throughout the rearing period. On the day of tagging, the stocking density was reduced to 6 individuals per container. This will allow for the evaluation of final individual weights and survival at the end of the study period.

[0042]

[0043] Control plan: The temperature (°C) was monitored daily (07:30 and 16:00). Siphoning of leftovers, purging, and counting of the number of shrimp per tank (survival monitoring) were also carried out 5 times a week (excluding weekends and holidays). Where applicable, observations were recorded concerning molting periods, animal behavior, or any other parameter of interest.

[0044]

[0045] Preparation of Hermetia illucens flour

[0046] The flour is obtained from H. Illucens larvae which are heated, mechanically separated into 3 phases (mechanical extraction, without the use of solvent), dried and then ground.

[0047] The larvae are killed by immersion in water heated to approximately 70°C. The devitalized larvae are ground and then heated to a minimum of 90°C. The resulting product is mechanically separated into three phases: the solid portion (cake), a liquid portion containing water-soluble nutrients (glue water), and the oil. The flour, composed of the cake, glue water, and antioxidant, is dried. The moisture content of the flour at the milling stage is between 5 and 10%. Finally, the flour is ground. The particle size of the flour at the milling stage is less than 2 mm.

[0048] Preparation and characteristics of the target experimental foods:

[0049] The compositions include, in addition to animal and vegetable meals, the ingredients typically found in shrimp feed, namely: oil, amino acids, vitamins, and minerals. Feeds 1 to 7, the composition of which is described in Table 1, are obtained by substituting, in a 1:1 ratio, an increasing proportion of fishmeal in the control feed with HL meal. This results in feeds comprising approximately 30% by weight of animal meal consisting of fishmeal and HI meal, and exhibiting varying HI meal content in this animal meal, equal to the replacement rate of fishmeal in the control feed with HI meal (Table 2). For each of feeds 1 to 7, the control feed represents an equivalent feed containing fishmeal instead of HI meal.

[0050]

[0051] [Tables 1] Feed Control 1 2 3 4 S 6 7 HI Flour 0 3 6 9 12 19 28 33 Fishmeal 30 27 24 22 19 12 5 0 Wheat Flour 40 40 40 39 39 38 35 35 Soybean Meal 15 15 15 15 15 16 17 17 Gluten 5 5 5 5 5 5 5 5 5

[0052] Table 1: Composition of foods in % (main ingredients)

[0053]

[0054] Formulas for calculating the parameters studied in this study:

[0055] - Weight gain (GP ; %) = [(Pfinai-Pinitiai) * 100] / Pinitiai where P is the individual weight;

[0056] - Quantity ingested (Ing. ; g / individual) = Quantity ingested / Nb where Q is the quantity of food ingested and Nb is the number of individuals;

[0057] - Conversion index (CI) = Ing. / GP, which corresponds to the conversion rate eating

[0058]

[0059] Results

[0060]

[0061] [Tables2] HI content of animal meal* (%) Weight gain (%) Quantity ingested (g / individual) Conversion ratio Control 0 21.24s±19.01 4.02a±0.33 4.45a+1.63 Feed 1 10 27.08ab+ 23.27 6.68ab+ 1.71 4.47a+0.43 Feed 2 20 36.68ab+24.36 7.81ab± 2.11 3.65a±1.10 Feed 3 29 38.01ab+117.84 8.32b+2.66 3.27a+0.20 Feed 4 39 44.67ab+22.16 7.22a4 2.00 3.068+0.23 Feed 5 61 43.58c±15.23 7.56afe±l.60 3.35s+0.62 Food 6 85 29.66^+15.37 7.40ab+l.42 4.508+Q.97 Food 7 100 16.71a±12.80 8.88b+ 1.83 9.81*16.95

[0062] Table 2: Mean values ​​obtained for weight gain, amount of feed ingested, and feed conversion ratio, along with their standard deviations, according to the different experimental feeds. Values ​​associated with the same letter do not show significant differences (Fisher's exact test, p > 0.05). (* animal meal = fish meal + HI meal)

[0063]

[0064] Regarding weight gain, the results are presented in Table 2, as well as in [Fig. 1]. It can be observed that feeds 2 to 5, which correspond to an HI meal content ranging from 20 to 61% of the 30% animal meal (fish meal + HI meal), show significantly higher weight gains than that observed for the control feed. In particular, it can be observed that feeds 4 and 5, characterized in that the HI flour represents respectively 39% and 61% of the animal flour, show weight gains almost twice as high as the control group.

[0065]

[0066] Regarding feed intake, higher quantities were observed compared to the control feed, indicating greater palatability. The results also show a numerical correlation between the amount of feed ingested and the HI content of the animal meal, ranging from 10% to 29%. In particular, the amount ingested for feed 3, which corresponds to an HI meal content of 29%, is significantly higher than that associated with the control feed.

[0067]

[0068] The feed conversion ratio (FCR) provides an objective measure combining both feed intake and growth data. The FCR thus provides information on the animals' capacity to convert feed into biomass. In this experiment, the results show that the FCR of feeds containing Hermetia illucens meal tends to be numerically lower than that of the control feed. This implies that, for the same or even a smaller quantity of feed ingested, shrimp fed a diet containing HI meal exhibit greater weight gain than those fed an equivalent diet containing fishmeal instead of HL meal.

[0069] Conclusion: These experiments, which consisted of substituting fishmeal with HI meal in a 1:1 ratio (using a conventional fishmeal-based feed as a reference), demonstrate better growth performance with feeds containing HI meal compared to an equivalent feed containing fishmeal instead of HL meal.

[0070] EXAMPLE 2: Improvement of the yield of a L. stylirostris shrimp farm by the introduction of an improved feed comprising Hermetia illucens meal Materials and methods

[0071] Experimental conditions; This experiment was carried out on shrimp of the species L. stylirostris. The experimental area consisted of 40 50L tanks and their water supply tanks. A 100% hourly seawater exchange rate was applied to all tanks. The quality of the seawater supply was ensured by a mechanical filtration system. In addition, water temperature control was achieved using a chiller and / or heating elements in the tanks. Only salinity (natural salinity around 35‰) and photoperiod were not continuously monitored. This experiment was carried out with animals from a support tank (Ifremer / LEAD- NC) with an initial mean weight of 5.83 ± 1.23 g and a stocking density of 7 individuals / tray. The transfer took place 7 days before the start of the study to acclimate the animals to the experimental conditions. During this period, individual weighing and tagging of the animals were carried out to establish individual initial weights and allow for their identification throughout the rearing period. On the day of tagging, the stocking density was reduced to 6 individuals / tray. Thus, the final individual weights and survival could be assessed at the end of the study period.

[0072] Control plan j. The temperature (°C) was monitored daily (07:30 and 16:00). Siphoning of leftovers, purging, and counting of the number of shrimp per tank (survival monitoring) were also carried out 5 times a week (excluding weekends and holidays). Where applicable, observations were recorded concerning molting periods, animal behavior, or any other parameter of interest.

[0073] Preparation and characteristics _ of the target experimental foods j.

[0074] The compositions include, in addition to animal and vegetable meals, the ingredients typically found in shrimp feed, namely: oil, amino acids, vitamins, and minerals. Feeds 1 to 7, the composition of which is described in Table 3, are obtained by substituting, in a 1:1 ratio, an increasing proportion of fishmeal in the control feed with HL meal. This results in feeds comprising 30% by weight of animal meal made up of fishmeal and HI meal, and exhibiting varying HI meal content in this animal meal, equal to the replacement rate of fishmeal in the control feed with HI meal (Table 4). For each of feeds 1 to 7, the control feed represents an equivalent feed containing fishmeal instead of HI meal.

[0075] [Tables3] Food Control 1 2 3 4 5 6 7 HI Flour 0 3 3.6 4.2 4.8 5.4 6 12 Fishmeal 30 27 26.4 25.8 25.2 24.6 24 18 Wheat Flour 37 37 37 37 37 37 37 36.5 Soybean Meal 17 17 17 17 17 17 17 18 Gluten 5 5 5 5 5 5 5 5 5

[0076]

[0077] Table 3: Composition of foods in % (main ingredients)

[0078] Formulas for calculating the parameters studied in this study:

[0079] The parameters studied are the same as in Example 1.

[0080] Results

[0081] [Tables4] HI content of animal meal* W Weight gain (%) Amount ingested (g / individual) Conversion ratio Control 0 38.77a±16.7 8.64a±11.87 3.56a±0.53 Feed 1 10 37.77a± 12.78 8.48s± 2.08 3.36a±0.32 Feed 2 12 41.25ab±12.50 8.21a± 1.81 3.30a±0.36 Feed 3 14 41.31sb ±14.18 8.89a±11.83 3.443±0.71 Feed 4 16 39.73ab ±12.19 9.098± 1.46 3.463±0.60 Food 5 18 45.08ab ±14.16 8.22'±1.87 3.04a±0.44 Food 6 20 41.25ab ±11.10 8.643±1.83 3.44a±0.23 Food 7 40 47.16b ±15.58 9.42a±1.89 3.34a±G.42

[0082]

[0083] Table 4: Mean values ​​obtained for weight gain, amount of feed ingested, and feed conversion ratio, along with their standard deviations, according to the different experimental feeds. Values ​​associated with the same letter do not show significant differences (Fisher's exact test, p > 0.05). (* animal meal = fish meal + HI meal)

[0084] Regarding weight gain, the results are presented in Table 4 and in [Fig. 2]. Weight gains greater than those of the control feed were observed for feeds 2 to 7. Although the weight gains did not show a significant difference compared to the control feed, a linear trend could be observed. Furthermore, feed 7, which corresponds to a HI meal content of 40% of the 30% animal meal (fishmeal + HI meal), showed a significantly higher weight gain than that observed for the control feed.

[0085] With regard to food intake, no significant difference is observed, which reflects an equivalent palatability.

[0086]

[0087] Finally, regarding the conversion index, a graphical representation of the results is presented in [Fig. 3]. The results show that the conversion index of Feeds containing Hermetia illucens meal tend to be numerically lower than with the control feed, implying that for the same or even a lower amount of feed ingested, shrimp fed with a feed including HI meal exhibit a higher weight gain than those fed with an equivalent feed containing fishmeal instead of HI meal.

[0088] Conclusion: These experiments, which consisted of substituting fishmeal with HI meal in a 1:1 ratio (using a conventional fishmeal-based feed as a reference), demonstrate improved weight gain with a feed containing 40% HI meal compared to an equivalent feed without HI meal. The results relating to the preservation index show a decrease compared to the feed conversion ratio of the control feed.

[0089] EXAMPLE 3: Improving the yield of a Litop enaeus vannamei shrimp farm by providing an improved feed containing Hermetia illucens meal. Materials and methods

[0090] Experimental conditions These experiments were carried out on shrimp of the species Litop enaeus vannamei.

[0091] The experimental area consisted of 12 tanks of 290 L each. Shrimp larvae were reared in a recirculating water system containing artificial seawater at a salinity of 20 g L⁻¹. A complete biological / mechanical filter and regular water changes kept the total ammonia (NH₃ / NH₄⁺) concentration below 0.05 mg L⁻¹ and the nitrite (NO₂) concentration below or equal to 0.8 mg L⁻¹. The water temperature was maintained constant at 27°C ± 1°C using an automatic temperature control system. A total of 1200 shrimp with an average body weight of approximately 0.1 g were used to randomly compose 12 groups of 100 individuals. Each group was housed in a feeding unit. Each experimental diet was allocated to 3 feeding units. The total weights of the groups were measured at the beginning of the experiment and at 28 days.

[0092] Preparation and characteristics of the experimental foods:

[0093] High-protein (HI) flour was added to the other ingredients (fishmeal, vegetable flours, amino acids, vitamins, and minerals) and the mixture was thoroughly homogenized. To granulate the resulting mixtures, a feed binder and water were added. The resulting paste was passed through a granulation machine. The temperature during the procedure did not exceed 50°C. Two kilograms of each feed were produced.

[0094] Foods A, B and C, the composition of which is described in Table 5, are obtained by substituting, in a 1:1 ratio, an increasing proportion of fishmeal The control feed contains HL meal. This allows for the production of feeds containing 15% by weight of animal meal, composed of fishmeal and HI meal, and exhibiting varying HI meal content within this animal feed, equal to the replacement rate of fishmeal in the control feed with HI meal (Table 6). For each of the feeds thus obtained, the control feed represents an equivalent feed containing fishmeal instead of HI meal.

[0095] [Tables5] ABC Control Feed HI Flour 0 4.5 7.5 10.5 Fishmeal 15 10.5 7.5 4.5 Wheat Flour 35 33 32 32 Soybean Meal 30.5 32.5 33 33.5

[0096] Table 5: Composition of foods in % (main ingredients)

[0097] During the experimental period, food was distributed automatically 6 times a day. The shrimp groups received their respective diet according to a daily ration calculated from the average weight of the shrimp (standard percentage of weight) and adjusted daily according to expected growth, observed mortality and feed consumption per group.

[0098] Performance was evaluated according to the following parameters: • Weight gain • Specific growth rate (SGR; % / day) = [(ln Pfinai - ln Pinçai)* 100] / 1 where t is the duration in days • Power conversion rate • Survival rate

[0099] The shrimp used in this experiment are certified free of specific pathogens (SPF) for the following pathogens: IMNV, EHP, WSSV, TSV, YHV, NHP-B, IHHNV, CMNV, PvNV, MBV, HPV, AHPND / EMS, BP. Triplicate groups of shrimp were fed the diets described in Table 5 for 28 days. This procedure allowed for the evaluation of the effect of these diets on the growth performance of the shrimp. Three days before the start of the pathogen resistance test, the shrimp were transferred to 10 L infection units filled with artificial seawater (1 shrimp per unit) to allow for acclimatization. For the resistance test to the virus responsible for white spot syndrome, 3 blocks of 10 individuals each were formed at Starting with shrimp from each of groups A, B, and C, one block for the negative control (mock) and three for the positive control were created from shrimp in group CTRL. The shrimp were inoculated orally with the viral preparation. After inoculation, the shrimp were fed twice daily with their respective diets. Clinical signs of disease and mortality were monitored twice daily. The same protocol was implemented for the resistance test against the bacterium responsible for severe pancreatic necrosis syndrome, except that the pathogen was a bacterium and was inoculated by immersion. Viral preparation

[0100] The WSSV Thai-1 strain (Escobedo-Bonilla et al., 2005) was used in this experiment. A stock of this virus is stored at -70°C. This strain was previously isolated in Thailand from naturally infected Penaeus monodon and passed once into the crayfish Pacifastacus leniusculus (Jiravanichpaisal et al., 2001) as follows. A frozen stock of crayfish gill suspension (certified free of other major shrimp pathogens) was injected into Litopenaeus vannamei free of specific pathogens (SPF) to amplify the virus.

[0101] The resulting infected shrimp carcasses were used to prepare a WSSV suspension and immediately frozen. The infection level was then determined according to the procedure described by Escobedo Bonilla et al. (2005). This inoculum was used to infect shrimp intramuscularly. The resulting infected carcasses were used to prepare the WSSV solid inoculum, which was used in the oral infection experiment. Uninfected shrimp carcasses subjected to the same procedure but inoculated with a virus-free suspension were used to prepare a blank solid inoculum (mock). Bacterial preparation

[0102] The bacterium used in this experiment is Vibrio parahaemolyticus isolated from shrimp infected with AHPNS / EMS. More specifically, the AHPND / EMS-specific strain TW01 was used in this experiment. This bacterium was isolated from infected shrimp tanks in Thailand. A stock of this bacterium is stored at -70°C. After thawing, the stock was aseptically inoculated into a culture medium and grown under standard conditions. Quantified suspensions of TW01 were used to inoculate the shrimp by immersion. Results Results on growth performance

[0103] The results on growth performance are presented in Table 6.

[0104] [Tableauxô] HI content of your animal meal* (%) Weight gain (g) Specific growth rate (% / day) Feed conversion ratio Control 0 0.42a±0.05 6.01=+0.33 i.703±0.17 A 30 0.57b+0.03 6.83b+0.14 l.42ab+0.07 B 50 0.61ta+0.01 7.08^0.22 l.31b+0.10 C 70 0.70c±0.03 7.53c+0.18 1.23^0.12

[0105] Table 6: Mean values ​​obtained for weight gain, specific growth rate, and feed conversion ratio, along with their standard deviations, according to the different experimental feeds. Values ​​associated with the same letter do not show significant differences (Fisher's exact test, p > 0.05). (* animal meal = fish meal + HI meal)

[0106] All groups of shrimp fed Hermetia illucens meal showed significantly higher performance compared to the control group in both weight gain and specific growth rate. The results are presented in Table 6 and Fig. 4. A significant overall improvement in weight gain and growth rate (measured by specific growth rate) was observed in shrimp fed diets A, B, and C compared to shrimp fed an equivalent diet without HI meal (CTRL). This improvement was proportional to the Hermetia illucens meal content in the animal meal.

[0107] The results also show a decreasing trend in feed conversion ratio correlated with increasing HI meal content in animal meal. In particular, the feed conversion ratio is significantly lower for diets B and C, which correspond to HI meal contents of 50% and 70% respectively of the 15% animal meal, than for diet CTRL. Results on the pathogen AHPNS:

[0108] [Tables7] HI content of animal meal* (%) Final mortality in the AHPNS resistance test (%) Mock 0 0±0 Control 0 60.0ac±20.0 A 30 68.92±1.9 B 50 73.3a±15.3 C 70 46.7b±15.3

[0109] Table 7: Mean final mortality values ​​obtained in the AHPNS resistance test, along with their standard deviations, according to the different experimental feeds. Values ​​associated with the same letter do not show significant differences (Fisher's exact test, p > 0.05). (* animal meal = fish meal + HI meal)

[0110] The results are presented in Table 7, as well as in [Fig.5].

[0111] As expected, mortality in the CTRL control group (positive disease control) ranged from 50% to 80%, while mortality in the Mock control group (negative disease control) was 0%. This demonstrates the validity of the protocol. No significant difference in mortality was observed between the groups fed diets A and B and the CTRL group. This demonstrates that replacing fishmeal with HI meal does not increase mortality from the bacteria responsible for acute hepatopancreatic necrosis syndrome. A significant reduction in mortality was observed with diet C, which corresponds to an HI content in the animal meal of 70%.

[0112] These results suggest that there is partial protection of shrimp against AHPNS infection when fishmeal is replaced by HI meal in shrimp growth diets. An HI meal content in the animal meal (or equivalently, a fishmeal-to-HI meal replacement rate) of 55–60% could be of interest for this application. Results on the WSSV pathogen:

[0113] [Tables8] HI content of animal meal (%) Final mortality in the WSSV resistance test (%) Mock 0 0±0 Control 0 76.74+23.1 A 30 43.3b±15.3 B 50 56.7^+15.3 C 70 53.3^+11.5

[0114] Table 8: Mean final mortality values ​​obtained in the WSSV resistance test, along with their standard deviations, according to the different experimental feeds. Values ​​associated with the same letter do not show significant differences (Fisher's exact test, p > 0.05). (* animal meal = fish meal + HI meal)

[0115] The results are presented in [Fig.6].

[0116] As expected, mortality in the CTRL control group (positive control for the disease) ranged from 50% to 80%, while mortality in the Mock control group (negative control for the disease) was 0%. This demonstrates the validity of the protocol. A general trend was observed showing higher survival rates in shrimp fed diets A, B, and C than in the positive control group. Statistically, this improvement was significant for the group fed diet A. These results suggest that the inclusion of HI meal in the shrimp diet can significantly improve their resistance to WSSV at an HI meal content in the animal meal (or equivalently, a fishmeal replacement rate of HI meal) of 30%.The reduction in mortality observed with diets B and C suggests that there is generally partial protection of shrimp against WSSV infection when fishmeal is replaced with HI meal in shrimp growth diets. A replacement rate of 40 to 60% of fishmeal with HI meal could be beneficial for this application.

[0117] Conclusion: These experiments, which consisted of substituting fishmeal with HI meal in a 1:1 ratio (using a conventional fishmeal-based feed as a reference), show better growth performance in shrimp fed with feeds containing HI meal compared to an equivalent feed containing fishmeal instead of HL meal.

[0118] Furthermore, partial protection of shrimp to AHPNS and WSSV infection is observed when fishmeal is replaced with HI meal in Shrimp growth regimes. HI meal could help improve shrimp survival to AHPNS and WSSV pathogen infection when used as a replacement for fishmeal in shrimp feed.

Claims

Demands

1. Shrimp rearing feed for improving rearing yield comprising 5 to 30% animal meal consisting of fishmeal and Hermetia illucens larvae meal, wherein said Hermetia illucens larvae meal represents between 40 and 60% of said animal meal for its use in improving resistance to infections.

2. Food according to claim 1 for its use according to claim 1, to improve resistance to viral infections.

3. Food according to claim 2 for its use according to claim 2, to improve resistance to the virus responsible for white spot syndrome.

4. Food according to claim 1 for its use according to claim 1, to improve resistance to severe hepatopancreatic necrosis syndrome.

5. Food according to any one of claims 1 to 4 for its use according to any one of claims 1 to 4, wherein said shrimp are selected from the species Litopenaeus vannamei, Litopenaeus st ylirostris and Penaeus monodon.

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