FEED TO IMPROVE THE PERFORMANCE OF A DECAPOD FARM

Abstract

The invention relates to the field of aquaculture. More particularly, the invention relates to the use of a feed comprising Hermetia illucens flour for improving the aquaculture yield of a decapod farm, in particular shrimp farms.

Description

Title of the invention: FEED FOR IMPROVING THE YIELD OF A DECAPOD FARM

[0001] The invention relates to the field of aquaculture. More particularly, the invention relates to the use of a feed comprising Hermetia illucens flour for improving the aquaculture yield of a decapod farm, in particular shrimp farm. Field of invention

[0002] Decapods are crustaceans valued for the taste qualities of their flesh, particularly that of shrimp, langoustine, crayfish, crayfish, lobster and crab. Industrial farming methods are developing. Performance objectives must take into account the ecological footprint of these methods, and in particular the availability of food resources.

[0003] Pacific white shrimp (Litopenaeus vannameï) is the most widely produced shrimp species in the world, with production volumes exceeding 4.1 million metric tons in 2016 (FAO 2018).

[0004] One of the most widely used ingredients in aquaculture feed is fishmeal. This meal has a major advantage: it is very rich in easily digestible animal proteins. However, the production of fishmeal could become a limiting factor in a context of sustained expansion of aquaculture, particularly shrimp farming. Thus, the aquaculture sector is looking for alternative protein sources to fishmeal.

[0005] Plant-based ingredients have become, over the last decades, commonly used ingredients in the formulation of aquafeeds (Barrows et al. 2007, Gatlin et al. 2007, Oliva-Teles et al. 2015). They have thus been successfully used to replace part of the fishmeal in the formulas of these feeds. However, plant proteins present certain nutritional limitations for aquafeeds: presence of antinutritional factors, high levels of fiber and non-starch polysaccharides, inadequate fatty acids, unbalanced profiles of essential amino acids, and reduced digestibility and palatability. In addition, a complete substitution of fishmeal with plant ingredients may lead to additional pressures on essential agricultural resources and on the environment (considering for example the deforestation linked to soybean cultivation).Thus, research efforts have been made to find more effective alternative ingredients, among which insect flours constitute. an interesting alternative to vegetable and fish flours, often as a partial substitute.

[0006] The larvae of many insect species, such as locust, grasshopper, termite, mealworm, Asian rhinoceros beetle, giant mealworm, domesticated silkworm, housefly, common mosquito, and black soldier fly have been studied for the production of insect ingredients (Henry et al. 2015). Among these insect species, the black soldier fly (Hermetia illucens) is a very promising species for the production of aquafeeds, as mass rearing techniques for the industrial production of high-quality insect meal from this species are much more advanced in their development process.

[0007] The amino acid profile of insects of the order Diptera, which includes the black soldier fly (Hermetia illucens), shows a greater level of similarity to fish meal than soybean meal, but also to meal from other insects (Orthoptera and Coleoptera) (Barroso et al. 2014). Insect meal from the black soldier fly also has a high protein content (50-70%), and these have been shown to be highly digestible.

[0008] Chitin in insect meal has also been shown to modulate the immune system of shrimp and fish, which may have beneficial effects on health and disease resistance (Mousavi et al 2020, Gasco et al 2018).

[0009] However, the prior art does not describe any particular benefit linked to the use of Hermetia illucens (HI) flour in decapod farming.

[0010] In particular, the article by Cummins et al (2017) describes compositions comprising HI flour obtained by alcoholic extraction, combined with soy flour. In these trials, the inclusion rate of HI flour is between 7% and 36%. No significant difference in terms of growth performance or survival was observed in shrimp whose diet included HI flour.

[0011] The article by Mastoraki et al. (2019) reports a comparative study of two diets comprising insect meal, including HI, combined with either vegetable meal or fish meal. In these trials, the inclusion rate of HI meal is 7.8%. This study shows an improvement in the growth performance of shrimp fed with formulations containing HI insect meal or Musca domestica and fish meal compared to a diet comprising Tenebrio molitor meal.

[0012] Shrimp farms are also affected by pathogens such as the Vibrio bacteria responsible for acute hepatopancreatic necrosis syndrome (AHPNS) and the virus responsible for white spot syndrome (WSSV). A subject of interest for shrimp farmers is therefore to have solutions to strengthen shrimp resistance to these pathogens, causing epidemics affecting shrimp production worldwide.

[0013] To support the growth of the decapod production industry, it is necessary to find high-performance feed ingredients that can be produced sustainably and to improve the efficiency of production systems to deliver higher volumes while putting less pressure on natural resources. Protecting both the long-term potential of the industry and preserving natural resources is a growing challenge, not only in the context of the production of decapods such as the shrimp L. vannamei, but also in all modern food production systems.

[0014] Given the challenges involved in breeding decapods, a feed that can increase yield is being sought. Statement of the invention

[0015] Unexpectedly, the inventors have shown that HI larva flour is of particular and specific interest in improving the yield of decapod farming in aquaculture.

[0016] Thus, the present invention relates to the use of a feed for decapods comprising from 1% to 25% by weight of HI larva meal, to improve breeding yield. Advantages of the invention

[0017] The invention aims to provide an improved feed for decapods. This feed comprises HI flour, which is reported for the first time to have particularly interesting properties for decapods, particularly for shrimp.

[0018] The addition of HI flour to a feed intended for feeding decapods makes it possible to significantly improve breeding performance. This improvement is observed on several key parameters in aquaculture.

[0019] First of all, the use of this feed makes it possible to increase the weight gain and the growth rate of the decapod and this in a linear manner up to a rate of incorporation of the Hermetia illucens flour of approximately 15%, and overall over a range from 1% to 25% by weight compared to a control feed without insect flour. An improvement in the growth rate implies that the decapods reach a given weight in a reduced time, which results in a reduction in fixed production costs.

[0020] This feed also makes it possible to improve the feed conversion rate proportionally to the rate of incorporation of Hermetia illucens flour. This parameter is economically essential for controlling the cost of production in aquaculture, since thanks to this food, decapods reach the same weight thanks to a smaller quantity of food.

[0021] Finally, the use of this feed makes it possible to increase resistance to infections during breeding. This results in a reduction in the mortality rate. In particular, the use of this feed makes it possible to increase resistance to viral infections, in particular to the virus responsible for white spot syndrome, which is very widespread in shrimps, but more generally present in decapods. The use of this feed also makes it possible to increase resistance to bacterial infections, in particular to the Vibrio bacterium responsible for acute hepatopancreatic necrosis syndrome. DETAILED DESCRIPTION OF THE INVENTION

[0022] A first object of the invention relates to the use of a feed for decapods comprising between 1% and 25% by weight of Hermetia illucens larvae flour to improve breeding yield.

[0023] By "improved yield" is meant higher production, namely higher weight gain and growth rate, but also more profitable production due to an improved feed conversion rate. In addition, the notion of yield also covers the fact that the feed allows better resistance to infections; by minimizing mortality within the herd, overall production is improved.

[0024] The inventors have found that the inclusion of HI flour in a decapod feed significantly improves the nutritional properties of this feed, i.e. the decapods exhibit a faster and higher weight gain than in the absence of HL flour.

[0025] In a preferred embodiment, the HI flour is obtained via a mechanical preparation process, without chemical treatment, without extraction in a solvent. Such a mechanical process may be a mechanical extraction of the solid part of the larvae previously ground and heated, followed by drying and grinding of this solid part to obtain flour.

[0026] The benefits of using a feed according to the invention are observed as soon as the feed comprises 1% HI flour. In a preferred embodiment, the feed comprises between 3% and 25% HI flour, even more preferably between 5% and 25%, or even between 10% and 25%. In a particular embodiment, the feed comprises between 10% and 20% HI flour.

[0027] The feed generally includes a protein intake complementary to that of the HL flour. This is provided by an animal flour, a vegetable flour or a mixture of the two. The vegetable flour can be chosen from wheat flour, soy flour, or any other suitable flour, alone or in a mixture. Similarly, the flour animal meal may be chosen from fish meal, poultry meal or any other suitable meal, alone or in a mixture.

[0028] A person skilled in the art knows how to prepare a basic feed that meets the needs of decapods in terms of proteins, amino acids, vitamins and minerals. HI flour can therefore be added to an existing formulation to improve its performance, or can partially or completely replace one of the components of a decapod feed.

[0029] The use of a food according to the invention improves the weight gain and growth rate of decapods. In particular, the weight gain can thus be doubled as illustrated in Example 1.

[0030] The use of a feed according to the invention improves the feed conversion rate.

[0031] The use of a food according to the invention improves the resistance to infections of the decapod.

[0032] More particularly, this feed improves resistance to viral infections. In a preferred embodiment, it improves resistance to the virus responsible for white spot syndrome in decapods called WSSV (white spot syndrome virus). In this preferred embodiment, the feed comprises at least 4.5% HL ​​flour

[0033] This feed also improves resistance to bacterial infections. In a preferred embodiment, it improves resistance to severe pancreatic necrosis syndrome caused by V. parahaemolyticus TW01 strain (AHPNS). In this preferred embodiment, the feed preferably comprises at least 10% HL flour

[0034] For the purposes of the invention, the term "decapod" covers shrimp, langoustine, crayfish, spiny lobster, lobster and crab. In a preferred embodiment, the decapod is a shrimp. The shrimp may be chosen from the following species: Litopenaeus vannamei, Litopenaeus stylirostris and Penaeus monodon.

[0035] The present invention will be better understood from reading the following examples, provided for illustration purposes and in no way to be considered as limiting the scope of the present invention. DESCRIPTION OF FIGURES

[0036] [Fig. 1][Fig. 1]: Graphical representation of the average weight gain (%) of shrimps as a function of the incorporation rate of Hermetia illucens flour. The horizontal line materializes the observation of a weight gain compared to the control feed. The oblique line materializes the positive trend observed regarding weight gain. Values ​​associated with the same letter do not show any significant difference between them (Fisher test, p > 0.05).

[0037] [Fig.2] [Fig.2]: Graphical representation of the average weight gain (g) of shrimp depending on the food ingested. CTRL corresponds to the control food not containing Hermetia illucens flour, while A, B and C correspond to foods containing 4.5%, 7.5% and 10.5% HI flour respectively. Values ​​associated with the same letter do not show any significant difference between them (Fisher test, p > 0.05).

[0038] [Fig.3][Fig.3]: Graphical representation of cumulative shrimp mortality subjected to WSSV infection depending on the food ingested. “Mock” ​​corresponds to the disease-negative control group, and “CTRL” to the disease-positive control group. Shrimp in these groups were fed with the control feed without Hermetia illucens meal. A, B and C correspond to feeds containing 4.5%, 7.5% and 10.5% HI meal, respectively

[0039] [Fig.4] [Fig.4]: Graphical representation of cumulative shrimp mortality subjected to AHPNS infection depending on the food ingested. “Mock” ​​corresponds to the negative control group for the disease, and “CTRL” to the positive control group for the disease. The shrimp in these groups were fed with the control feed without Hermetia illucens meal. A, B and C correspond to the feeds comprising respectively 4.5%, 7.5% and 10.5% of HI meal EXAMPLES

[0040] EXAMPLE 1: Improving the yield of a L. stylirostris shrimp farm by providing a feed enriched with Hermetia illucens flour Materials and methods

[0041] Experimental conditions: This experiment was carried out on shrimps of the species L. stylirostris. The experimental area consists of 40 50L tanks and their water supply tank. A seawater renewal of 100% per hour was applied to all the tanks. The quality of the seawater supply is ensured by a mechanical filtration system. In addition, thermoregulation of the water was carried out by means of a "cold group" and / or resistances in the tanks. Only the salinity (natural salinity around 35%o) and the photoperiod do not have a continuous control system. This experiment was carried out with animals from a support tank (Ifremer / LEAD-NC) with an initial average weight of 5.83+1.23g and at a density of 7 individuals / tank. The transfer was carried out 7 days before the start of the study in order to acclimatize the animals to the experimental conditions.During this period, individual weighing of the animals and their marking were carried out in order to establish the initial individual weights. and allow their identification throughout the breeding period. On the day of marking, the density was reduced to 6 individuals / tank. Thus, the final individual weights and survival could be assessed at the end of the study period.

[0042] 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 per week (excluding weekends and public holidays). Where appropriate, observations were recorded regarding moulting periods, animal behavior or any other parameter of interest. Preparation of Hermetia illucens flour:

[0043] 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.

[0044] The larvae are killed by immersion in water heated to approximately 70°C. The devitalized larvae are ground and then heated to at least 90°C. The product thus obtained is mechanically separated into 3 phases: the solid part (cake), a liquid part containing water-soluble nutrients (glue water) and the oil. The flour, composed of the cake, the glue water and the antioxidant, is dried. The humidity at the outlet of the flour is between 5 and 10%. Finally, the flour is ground. The particle size of the flour at the outlet of the mill is less than 2 mm.

[0045] Preparation and characteristics of the target experimental foods:

[0046] The composition includes, in addition to animal and vegetable flours, the ingredients conventionally contained in food for decapods, namely: oil, amino acids, vitamins and minerals.

[0047] [Tables 1] Control Foods 1 2 3 4 5 6 7 H1 Flour 0 3 6 9 12 19 28 33 Fish Meal 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

[0048] Table 1: Composition of food in % (main ingredients)

[0049] Formulas for calculating the parameters studied in this study:

[0050] - Weight gain (WG; %) = [(Pfinai-Pinitiai) * 100] / Pinitiai where P is the individual weight;

[0051] - Quantity ingested (Ing.; g / individual) = Qingéré / Nb where Q is the quantity of food ingested and Nb the number of individuals;

[0052] - Conversion index (CI) = Ing. / GP, which corresponds to the conversion rate eating Results

[0053] [Tables2] HJ content (%! Weight gain (%) Intake quantity (g / indivdu) Conversion index Control 0 21.24a+19.01 4.02a±0.33 4.45a±l.63 Feed 1 3.3 27.088¾ 23.27 6.68ab+ 1.71 4.47a+0.43 Feed 2 6.6 36.68^+24.36 7.81sb± 2.11 3.65a±l.10 Feed 3 9.9 38.01^+17.84 8.32%2.66 3.27a+0.20 Feed 4 13.2 44.67c+22.16 7.22ab+ 2.00 3.06a+0.23 Food 5 19.8 43.58c±15.23 7.568b+l.60 3.35a+0.62 Food 6 26.4 29.66abd+15.37 7.403b±l.42 4.50a+0.97 Food 7 33 16.71a+12.80 8.88¾ 1.83 9.81b+6.95

[0054] Table 2: Mean values ​​obtained in weight gain, quantity of food ingested and conversion index accompanied by their standard deviations according to the different experimental foods. The values ​​associated with the same letter do not present any significant difference between them (Fisher test, p > 0.05).

[0055] Regarding weight gain, the results are presented in Table 2, as well as in [Fig.l]. Weight gains greater than those of the control food are observed for foods 1 to 6. Even if the weight gains associated with lower HI flour incorporation rates do not show a significant difference compared to the control food, a linear trend is clearly observed, with values ​​that increase proportionally up to an HI flour incorporation rate of approximately 15%. Furthermore, the weight gains for foods 2 to 5, corresponding to an HI flour incorporation rate of 6.6% to 19.8%, are significantly higher than those associated with the control food. In particular, it is observed that foods 4 and 5, comprising respectively 13.2% and 19.8% of HI flour, show weight gains almost twice as high as the control group.

[0056] With regard to food intake, we again observe higher ingested quantities than those observed for the control food, which reflects a palatability higher. The results also indicate a numerical trend between the quantity of food ingested and the incorporation rate of HI flour between 3.3% and 9.9%. In particular, the quantity ingested for food 3, which corresponds to a 9.9% incorporation rate of HI flour, is significantly higher than that associated with the control food.

[0057] The conversion index makes it possible to obtain an objective measurement coupling both ingested and growth data. The IC therefore makes it possible to provide information on the capacity of the feed to transform into biomass of the animals. In this experiment, the results show that the IC of feeds with Hermetia illucens flour tends to be numerically lower than with the control feed, which implies that for the same quantity, or even a lower quantity of feed ingested, shrimps fed with a feed comprising HI flour show a higher weight gain.

[0058] Conclusion: These results show the beneficial effect of including Hermetia illucens flour in the shrimp diet, particularly on weight gain, feed intake and conversion index.

[0059] EXAMPLE 2: Improving the yield of a Litopenaeus vannamei shrimp farm by adding a feed enriched with Hermetia illucens flour Materials and methods Experimental conditions:

[0060] These experiments were carried out on shrimps of the species Litopenaeus vannamei.

[0061] The experimental area consists of 12 tanks of 290L. The shrimp larvae have were reared in a recirculating water system containing artificial seawater at a salinity of 20 g L1. A complete biological / mechanical filter and regular water changes kept the total ammonia (NH3 / NH4+) content below 0.05 mg Ll and the nitrite (NO2) content below or equal to 0.8 mg L1. The water temperature was kept constant at 27°C ± 1°C by means of 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.

[0062] Preparation and characteristics of experimental foods:

[0063] HI flour was added to the other ingredients (fish meal, vegetable flours, amino acids, vitamins and minerals...) and everything was thoroughly homogenized. In order to granulate the resulting mixtures, a feed binder and water were added. The resulting paste was passed through a granulating machine. The temperature during the procedure did not exceed 50°C. 2 kg of each feed was produced.

[0064] [Tables3] ABC Control Feed Flour Hl 0 4.5 7.5 10.5 Fish meal 15 10.5 7.5 4.5 Soybean meal 30.5 32.5 33 33.5 Wheat flour 35 33 32 32

[0065] Table 3: Composition of food in % (main ingredients)

[0066] During the experimental period, feed was distributed automatically 6 times a day. The groups of shrimp 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.

[0067] Performance was evaluated according to the following parameters: • Weight gain • Specific growth rate (SGR; % / day) = [(ln Pfinai - In Pinçai)* 100] / 1 where t is the duration in days • Feed conversion rate Results

[0068] [Tables4] H! Content w Weight Gain (g) Specific Growth Rate (% / day) Feed Conversion Rate Control 0 0.42s±0.05 6.01a±0.33 l.70a±0.17 A 4.5 0.57b±0.03 6.8340.14 l.425b+0.07 B 7.5 0.61^+0.01 7.08te+0.22 l.31s±0.10 C 10.5 0.70'±0.03 7.53=+0.18 1.23=+0.12

[0069] Table 4: Mean values ​​obtained in weight gain, specific growth rate and feed conversion rate accompanied by their standard deviations according to the different experimental foods. The values ​​associated with the same letter do not present any significant difference between them (Fisher test, p > 0.05).

[0070] All groups of shrimp fed with Hermetia illucens meal showed significantly higher performance compared to the control treatment (CTRL) for both weight gain and specific growth rate. The results are shown in Table 4, as well as in [Fig.2]. There was a significant overall improvement in weight gain and growth rate (measured by specific growth rate) in shrimp fed diets where HI meal was added compared to the control group (CTRL). This improvement was proportional to the level of inclusion of Hermetia illucens meal in the diet.

[0071] The results also show a decreasing trend in feed conversion rate correlated with the increase in the incorporation rate of HI flour in the diet. In particular, the feed conversion rate is significantly lower for diets B and C, which correspond to HI flour incorporation rates of 7.5% and 10.5% respectively, than for the CTRL diet. Conclusion :

[0072] The results of this Example show a significant improvement in weight gain, growth rate and feed conversion rate when including Hermetia illucens meal between 4.5% and 10.5% in the shrimp diet.

[0073] Furthermore, these results confirm those obtained in Example 1. Thus, it appears that HI flour is beneficial in different species of shrimp, in particular in L. stylirostris and in L. vannamei.

[0074] EXAMPLE 3: Improvement of resistance to the virus responsible for white spot syndrome in a shrimp farm by providing a feed enriched with Hermetia illucens flour Materials and methods Experimental conditions:

[0075] The experimental rearing conditions implemented are identical to those described in Example 2. The Litopenaeus vannamei shrimp used are certified specific pathogen free (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 with the diets described previously (Example 2) for 28 days. This procedure made it possible to evaluate 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 into 10L infection units filled with artificial seawater (1 shrimp per unit) to allow their acclimatization. For the resistance test to the virus responsible for white spot syndrome, 3 blocks of 10 individuals each were formed from shrimp from each of groups A, B and C. 1 block for the negative control (Mock) and 3 for the positive control were formed from shrimp from the CTRL group. The shrimp were orally inoculated with the viral preparation. After inoculation, the shrimp were fed twice a day with their respective diet. Clinical signs of disease and mortality were monitored twice a day. Viral preparation

[0076] WSSV strain Thai-1 (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 passaged once in 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 specific pathogen-free (SPF) Litopenaeus vannamei to amplify the virus.

[0077] 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 solid WSSV 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). Results

[0078] [Tables5] Treatment Hl content (%) Final mortality in WSSV resistance test {%) Mock 0 0±0 Control 0 76.7a+23.l A 4.5 43.3^15.3 B 7.5 56.7^+15.3 C 10.5 53.33b±11.5

[0079] Table 5: Mean values ​​obtained in final mortality in the WSSV resistance test accompanied by their standard deviations according to the different foods experimental. The values ​​associated with the same letter do not show any significant difference between them (Fisher test, p > 0.05).

[0080] The results are presented in Table 5, as well as in [Fig.3].

[0081] As expected, the mortality of the CTRL control group (positive control for the disease) is between 50 and 80% and that of the Mock control group (negative control for the disease) is 0%. This demonstrates the validity of the protocol. A general trend is observed showing higher survival of shrimp fed with a diet containing HI flour than in the positive control group. From a statistical point of view, this improvement is significant for the group fed with diet A. These results suggest that the inclusion of HI flour in the diet of shrimp can significantly improve their resistance to WSSV at an incorporation rate of 4.5%. The reduction in mortality observed with diets B and C suggests that there is generally an improvement in the resistance of shrimp to WSSV infection by the addition of HI flour in a shrimp farm during the growth phase.

[0082] EXAMPLE 4: Improvement of resistance to severe pancreatic necrosis syndrome caused by the V. parahaemolyticus strain in a shrimp farm by the addition of a feed enriched with Hermetia illucens flour

[0083] The experimental protocol implemented is equivalent to that described in Example 3 with the exception of the pathogen which is here a bacterium and which was inoculated by immersion. Bacterial preparation

[0084] 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 ponds in Thailand. A stock of this bacterium is stored at -70°C. After thawing, the stock was aseptically inoculated into culture medium and grown under standard conditions. Quantified suspensions of TW01 were used to inoculate shrimp by immersion. Results

[0085] [Tableauxô] HI content (%) Final mortality in AHPNS resistance test {%) Mock 0 0±0 Control 0 60.0ac±20.0 A 4.5 68.9a±1.9 B 7.5 73.3a±15.3 C 10.5 46.7b+15.3

[0086] Table 6: Mean values ​​obtained in final mortality in the AHPNS resistance test accompanied by their standard deviations according to the different experimental foods. The values ​​associated with the same letter do not present any significant difference between them (Fisher test, p > 0.05).

[0087] The results are presented in Table 6, as well as in [Fig.4].

[0088] As expected, the mortality of the CTRL control group (positive disease control) was between 50 and 80% while that of 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 with diets A and B and the CTRL group. This shows that the intake of a diet containing HI flour does not lead to an increase in mortality against the bacteria responsible for acute hepatopancreatic necrosis syndrome. A significant reduction in mortality is observed with diet C, which corresponds to an incorporation rate of HI flour of 10.5%.

[0089] These results suggest that the inclusion of HI meal in a shrimp growth diet can improve the resistance of these shrimp to AHPNS, particularly at an HI incorporation rate of 10.5%.

Claims

Claims

1. Decapod feed comprising between 1% and 25% by weight of Hermetia illucens larvae meal for use in improving resistance to viral infections.

2. Food according to claim 1 in which the quantity by weight of Hermetia illucens larva flour is between 5% and 25%.

3. Food according to one of claims 1 or 2 for its use according to one of claims 1 or 2, to improve resistance to the virus responsible for white spot syndrome.

4. Food according to one of claims 1 to 3 for its use according to one of claims 1 to 3, in which said decapod is chosen from shrimp, langoustine, crayfish, crayfish, lobster and crab.

5. Food according to claim 4 for use according to claim 4, wherein said decapod is a shrimp.

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