Shrimp Head Research Articles

Substitution of Soybean Meal by Shrimp Head Meal (Penaeus Monodon) in Poultry Ration for the Performance of Growing Pullets

To minimize the production cost of poultry and poultry products, it is important to formulate low cost balanced ration utilizing unconventional feed resources. Therefore, the experiment was carried out to measure the effect of substituting soybean meal (SBM) by different levels of shrimp head meal (SHM) to the ration of growing layer pullets. A control corn-soybean layer grower (pullet) diet and four different levels of SHM included diets as substitution of SBMwere fed to five groups of Hisex White pullets from 5th to 18th weeks of age. All groups of pullets fed isocaloric feeds (2765 Kcal kg-1). The control group T0 (0 % SHM+20 % SBM) received grower ration formulated with traditional feed ingredients with no substitution of SBM. The SBM contents of other treatment groups were substituted at the rate of 25 %, 50 %, 75 % and 100 % by the SHM and were adjusted as 5 % SHM+15 % SBM (T1), 10 % SHM+10 % SBM (T2), 15 % SHM+5 % SBM (T3) and 20 % SHM+0 % SBM (T4) keeping other ingredients constant as of control. Cumulative feed intake increased with the increasing level of SHM of diets. Feed cost and mortality rate decreased with the increasing level of SHM in the ration. Significantly lowest FCR at most of the age categories, highest cumulative body weight (p<0.05) at 18 weeks and highest weight at maturity (p<0.05) were found in treatment group fed 5 % SHM. Therefore, it can be concluded that substitution of 25 % SBM of the ration by SHM is suitable for the better performance of growing layer pullets.
 SAARC J. Agri., 18(2): 125-137 (2020)

An investigation into copper-binding capacity of the white leg shrimp head (Litopenaeus vannamei) protein hydrolysate

The aim of this study is to obtain the copper-binding protein hydrolysate from the white leg shrimp head (WLSH) by-product using enzymatic hydrolysis. The outcome indicated that the copper-binding capacity (CBC) of the WLSH protein hydrolysate achieved the maximum value of 19.4±0.5 mg Cu2+/g protein with hydrolysis conditions including Flavourzyme preparation, pH 7.5, 50°C, the enzyme:substrate (E:S) ratio of 80 U/g protein and 5h of hydrolysis. Under the pH treatment in a range of 1-11 or heat treatment at 100°C for up to 180 min, its CBC remained over 80%. The water holding capacity (WHC) and the oil-holding capacity (OHC) of the protein hydrolysate were 4.1±0.1 ml water/g protein hydrolysate powder and 4.5±0.1 ml oil/g protein hydrolysate powder, respectively. The solution also encompassed up to 8 essential amino acids, accounting for 36.1% of the total amino acid content. The protein hydrolysate could serve not only as a copper chelating agent, preventing copper-deficient or superfluous relating diseases, but also as a texturizer and an amino acid supplement fortified in various types of food.

EFEKTIVITAS KOMBINASI KEPALA UDANG, GAPLEK DAN MINYAK KELAPA SEBAGAI PENGGANTI SEBAGIAN JAGUNG TEPUNG TERHADAP PERFORMANS ITIK MOJOSARI JANTAN

The study was aimed to determine the effect of partially substitute corn with cassava flour, shrimp heads, and coconut oil on the performance of male Mojosari ducks. The 96 male daily old ducks were given treatment feed which was a combination of cassava flour, shrimp head, and coconut oil as corn substitutes with stratified proportions of 0, 5, 10, and 15. This was an experiment arranged according to a randomized block design with 4 treatments and 6 repetitions. The results showed that the combination of shrimp head, cassava, and coconut oil as corn to 15 percent has no difference in effect (P> 0.05) on feed consumption, metabolic energy consumption and protein consumption, carcass weight, thigh weight, and breast weight of duck age 6 Sunday. The conclusion is that the combination of shrimp heads, cassava, and coconut oil up to 15% could not affect the performance of male Mojosari duck.

ANALISIS PENGENDALIAN MUTU PADA PROSES PEMBEKUAN UDANG VANAME (Litopenaeus vannamei)

PT. XYZ is a company that processes vaname shrimp into frozen shrimp products. Frozen shrimp is a product that serves for export, so that it must meet predetermined quality standards. Quality measurement is determined to monitor a process under controlled or uncontrolled conditions. The method of measuring is the six sigma method. The purpose of this research is an alarm that is responsive, alert, and alert, attentive, alert and responds to frozen products using the six sigma method at PT. XYZ. The frozen peeled shrimp production process stages start from receiving raw materials, cutting shrimp heads, quality sorting and size separation, peeling the skin and taking the intestines, soaking, freezing shrimp, packaging, metal detection, and product packaging. The results showed that 1,904 frozen peeled shrimp with 43 defective products had a sigma level of 3,22 with possible damage of 40.363,38 for one million products (DPMO) and the proportion of wrong causes of defects, namely 44,2%. The proposed improvements to be carried out are to provide direction and advice to employees to be careful and thorough, and the company offers a unique tool for cleavage of shrimp.

Microbial Conversion of Shrimp Heads to Proteases and Chitin as an Effective Dye Adsorbent.

As a green and effective technique in the production of a large number of valuable products, the microbial conversion of chitinous fishery wastes is receiving much attention. In this study, protease production using the Paenibacillus mucilaginosus TKU032 strain was conducted on culture media containing several common types of chitinous fishery by-products serving as the carbon and nitrogen (C/N) nutrition source. Among the chitinous wastes, 1.5% (w/v) shrimp head powder (SHP) was found to be the most appropriate nutritional source for protease production when a maximal enzyme activity of 3.14 ± 0.1 U/mL was observed on the 3rd day of the culture period. The molecular mass of P. mucilaginosus TKU032 protease was estimated to be nearly 32 kDa by the polyacrylamide gel electrophoresis method. The residual SHP obtained from the culture medium was also considered to be utilized for chitin extraction. The deproteinization rate of the fermentation was estimated to be 45%, and the chitin obtained from fermented SHP (fSHP) displayed a similar characteristic Fourier-transform infrared spectroscopy (FTIR) profile as that from SHP. In addition, SHP, fSHP, and chitins obtained from SHP and fSHP were investigated for their adsorptive capacity of nine types of dyes, and chitin obtained from fSHP displayed a good adsorption rate on Congo Red and Red No. 7, at 99% and 97%, respectively. In short, the results provide potential support for the utilization of SHP in the production of P. mucilaginosus TKU032 protease via the fermentation as well as the preparation of chitin from fSHP as an effective dye adsorbent.

Bioactive compounds from by-products of shrimp processing industry in Vietnam

Shrimp heads from the shrimp processing industry in Vietnam can be a good source for production of bioactive compounds. It is estimated that there is an amount of 200,000 metric tons of shrimp by-products annually from two main species: black tiger shrimp (Penaeus monodon) and white shrimp (Penaeus vannamei). We found that the shrimp by-products can be used as raw materials for extraction of chitosan and lipid-mineral-rich carotenoprotein by combining chemical and biological treatment. Chitosan has been recognized as a multifunctional bioactive compound and has been used widely in food, biotechnology, cosmetics and medicine. Lipid-mineral-rich carotenoprotein can be used as a supplement in food and aqua-feed with good nutrional and functional properties. Besides, the characteristics of these products have been evaluated and reported. These results proved that high quality chitosan and lipid-mineral-rich carotenoprotein can be obtained from shrimp by-products.

Ameliorative effect of low molecular weight peptides from the head of red shrimp (Solenocera crassicornis) against cyclophosphamide-induced hepatotoxicity in mice

• Low molecular-weight peptides were prepared from Solenocera crassicornis head. • SCHPs-F1 ameliorated hepatotoxicity induced by cyclophosphamide in mice. • SCHPs-F1 restored endogenous antioxidants levels by activating the Nrf2 signal. • SCHPs-F1 suppressed hepatic inflammation through NF-κB signal pathway. • SCPHs-F1 relieved CTX hepatotoxicity as functional component. Our study was aimed at investigating the protective effect of low molecular weight peptides (SCHPs-F1) from red shrimp ( Solenocera crassicornis) head against cyclophosphamide-induced hepatotoxicity in mice. We found that SCHPs-F1 treatment dose-dependently normalized the biochemical markers, hepatic index, and total CYP450 enzyme content in CTX-induced hepatotoxicity in mice. SCHPs-F1 also ameliorated the CTX-mediated structural disorders of the hepatic tissue. Western blot results suggested that SCHPs-F1 significantly restored the levels of endogenous antioxidants (CAT, T-AOC, GSH-Px, SOD and MDA levels) through activating the Nrf2 signal by upregulating the expression of GCLM, HO-1, and NQO-1. Moreover, SCHPs-F1 improved the CTX-induced hepatotoxicity by inhibiting of NF-κB signal responses and down-regulating the expression of the inflammatory factors (IL-1β, IL-6, IFN-γ and TNF-α). These findings suggest that SCHPs-F1 can regulate Nrf2 and NF-κB signaling pathways and reduce the oxidative stress and inflammation in CTX-induced hepatotoxicity. Overall, SCHPs-F1 are value-added food ingredients for alleviating CTX-induced hepatotoxicity.

The quality of the shrimp head meal fermented using Bacillus sp. PAS7 isolates at different dosages of inoculum as fish feedstuff

Shrimp head is a feedstuff that potential to be developed as an alternative source of protein to substitute fish meal. It is because the shrimp head contains a high protein and its availability in Indonesia is quite abundant. However, this protein can not be utilized by fish because it contains high crude fiber (chitin) and ash which is difficult to digest. This study aimed to improve the quality of shrimp head meal by fermentation using Bacillus sp PAS7 at different inoculum doses and evaluate its nutrient content. The study was conducted in a completely randomized design (CRD) of four treatments and three replications. The treatment was carried out by varying concentrations of 0, 3, 5 and 7% per gram (weight) of shrimp head meal (v / w). Fermentation was done for three days at 28°C. The parameters measured were reducing sugar, soluble protein and proximate analysis (crude protein, crude fiber, ash and crude fat). The results showed that all dosage treatments had crude protein, soluble protein and crude fiber, which were better than control. Where dose of 7% had the highest soluble protein content (6.25 mg mL−1) and the lowest crude fiber content (15.02%) compared to other treatments.

Application of line balancing using the heuristic method to equalize the production line at PT.Bogatama Marinusa Makassar

PT. Bogatama Marinusa is one of the fishery industry sectors located in South Sulawesi that moves in shrimp processing and frosting as pioneer of fishery industry in southern Sulawesi. PT. Bogatama Marinusa certainly wants the planned production target to be achieved as expected, where every day the company processes raw materials with the capacity of approximately 575 kg for vannamei shrimp and 425 kg for black tiger shrimp. At deheading work station (shrimp head separation) and sortation area (sorting) materials buildup occurs in the production flow (bottle neck) which results an idle time to other work stations. With the existence of these problems, it is necessary to do production line balancing in order to minimize idle time and be able to balance the production lines so that the works carried out effectively and efficiently. The method used for overcoming the production line imbalance is by applying line balancing, namely the heuristic method, which is calculation using Regional Approach (RA) and Ranked Positional Weight (RPW) methods. Line efficiency (LE) increased by 83.33%, smoothing index (SI) decreased by 160.90, balance delay (BD) decreased by 16.66%, and idle time (IT) decreased by 264 minutes, and production capacity could be increase to 1,022 kg means that the results are far better than the current conditions.

The Effect of White Shrimp Head Chitosan Gel (Litopenaeus vannamei) on Inhibitory Strength of Periodontopathogenic Bacteria and Accelerating Wound Healing (In Vitro, Histological, and Clinical Tests)

Background: Chitosan has biocompatibility, non-toxic, biodegrade ability, and polyelectrolyte properties. It has been shown to be antimicrobial and accelerate wound healing. Chitosan gel from the waste of white shrimp head can be a new innovation which is effective to inhibit periodonto-pathogenic bacteria and to accelerate wound healing. Aim: To determine the potential of chitosan gel from white shrimp head (Litopenaeus vannamei) waste to inhibit periodonto-pathogenic bacteria and to accelerate wound healing in white mice (Mus musculus). Method: The research was experimental laboratory research. The design of this study was post-test only with control group design. Research on bacterial inhibition was done by 6-team, 5 times repetitions, and 5 treatments;1%, 2%, 3% chitosan gel positive control (Metronidazole disk) and negative control. The subjects of this wound healing research were 24 white mice (Mus musculus) with incisions on the back. They was divided into treatment groups and control groups with glycerol. Clinical and histological observations were carried out on days 1, 3, and 7. Result: The Mann Whitney test results showed a significant difference in inhibition of 1%, 2%, 3% chitosan gel against the Aggregatibacter actinomycetemcomitans bacteria (p

Calculation of optimal raw material purchase costs using normalized goal programming method

Supplier selection is a very important activity to build an effective supply chain. The purchasing department is the department responsible for determining the number of raw material purchases from several suppliers. The purchase of optimal raw materials is done using normalized goal programming. Supplier selection criteria serve as targets to minimize the cost of purchasing raw materials, minimize reject of raw materials, and minimize delays in raw materials. From the results of the study obtained an optimal allocation of raw material orders and calculated the optimal cost of purchasing raw materials. Finally, order allocation by selecting the right supplier can reduce purchasing costs by 6.51% rice bran raw material, 4.85% yellow corn raw material, and 4.71% shrimp head flour raw material.

Effect of the Substitution the Fish Meal with Shrimp Head Waste Fermented in Diet on Broiler Performance

The experiment aimed to investigate the effect of fish meal (FM) substitution with the shrimp head waste fermented (SHWF) in the diet on broiler performance. The SHWF is the shrimp waste fermented with Waretha inoculum containing Bacillus amyloliquefaciens bacteria. The materials used for this experiment were 100 day-old-chick (doc) Arbor Acres CP-707 strains unsexed. The experiment was arranged in Completely Randomized Design in five treatments and four replications with five chicks each. The broilers were randomly assigned in five different levels of SHWF as substitution of fish meal in the ration. The treatments were 0 % substitute (R0), 5 % FM substitute with SHWF (R1), 10 % FM substitute with SHWF (R2), 15 % FM substitute with SHWF (R3), and 20 % FM substitute with SHWF (R4) respectively. The result of this experiment indicated that feed consumption, weight gain, feed conversion ratio and body weight were not significantly (P > 0.05). However, the percentage of carcass and abdominal fat showed a significant effect (P <0.05). The conclusion of this experiment is that substitution FM with SHWF until 20% in broiler diet can maintain a performance broiler. In this treatment, were the consumption of 2428.28 grams/head, bodyweight gain 1330.07 g/head, feed conversion ratio of 1.82; body weight 1383.17 g, the percentage of carcasses was 73.86%, carcass fat was 2.67% and percentage of abdomen fat was 1.92 %.

Lipid Fingerprinting of Different Material Sources by UPLC-Q-Exactive Orbitrap/MS Approach and Their Zebrafish-Based Activities Comparison.

Lipids are considered to be critical contributors to nutrition, structural function, metabolic function, and other biological roles. They vary from one biological source to another. Here, the lipids from three common sources (soybean, egg yolk, and shrimp head) were comprehensively compared and characterized using the lipidomics approach, together with the UPLC-Q-Exactive Orbitrap/MS method. A total of 3027 lipid structures containing 778 fatty acids, 750 glycerolipids, 1283 glycerophospholipids, 200 sphingolipids, and 16 sterol lipids were first identified and quantified in these resources. The characteristic lipid species with significant differences among groups were determined by lipidomics analysis. Besides, the antithrombotic, antioxidant, and anti-inflammatory activities were evaluated based on the zebrafish model. The correlation between differential lipids and activities was also analyzed. Our comprehensive lipidomics profiling and bioactivities of lipids from different sources in vivo can provide evidence for their future applications.

Determination and characterization of vitamin B12 in the muscles and head innards of edible shrimp

We determined the vitamin B12 content in both the muscles and head innards of various shrimp species [Argis lar (Owen, 1839); Togezako shrimp, Argis toyamaensis (Yokoya, 1933); Pandalopsis japonica, Balss, 1914; Pandalus eous Makarov, 1935] using a microbiological assay based on Lactobacillus delbrueckii subsp. lactis ATCC7830. Approximately 2–4 µg vitamin B12/100 g wet weight—a considerable amount—was detected in shrimp muscles. The shrimp head innards contained significantly higher levels of vitamin B12 (~ 12–33 µg/100 g wet weight). Commercially available shrimp-innard products contained ~ 30 µg vitamin B12/100 g wet weight. We purified vitamin B12 compounds from the extracts of shrimp muscles and head innards using an immunoaffinity column. The muscle extract contained only one corrinoid compound, which was identified as vitamin B12 using liquid chromatography–electrospray ionization/tandem mass spectrometry, whereas the shrimp head innards contained three corrinoid compounds, which included large amounts of vitamin B12 and two smaller amounts of vitamin B12-d-monocarboxylic acid and tentatively identified vitamin B12 dicarboxylic acids.

Biofermentation: An efficient way to utilize shrimp head waste

Shrimp head waste (SHW) is rich in protein (40.37%) with excellent amount of amino acid which can easily be incorporated in fish feed preparation by replacing fish meal. The utilization of SHW is limited due to the presence of crude fiber (chitin) which interferes in digestibility of fish. This problem may be overcome through bio-fermentation using Bacillus subtilis (FPTB-13) which can reduce this crude fiber by the breakdown of glycosidic bond between protein and chitin converting the product easily digestible. Fermentation of shrimp head waste in biofermenter increases the amount of available protein with proper proportion of amino acid and reduces the fermentation time substantially as compared to conventional method.

Release principle of peptides and amino acids during the autolysis of shrimp head from Litopenaeus vannamei after UV-C irradiation stress.

UV‐C irradiation can activate endogenous enzymes in the body of many aquatic animals. Autolysis kinetics of shrimp head after UV‐C irradiation stress was investigated. During the first 5 hr of autolysis, the release of the autolysis products was in line with the first‐order equations of the reaction rate: Y = 37.681e−0.173 t, Pe = −1.769Y + 74.156, and TP = −1.5117Y + 60.866. A good linear correlation was founded between the release of total protein and that of products with molecular weight of 3,000 Da after these products associated with residual total protein were autolyzed. In contrast to the inconsistent effect of substrate concentration on autolysis rate constants, the effects of pH and temperature on the autolysis rate constants of shrimp head showed a consistent pattern. An Arrhenius equation (lnKa = 8,090.2/T − 26.497) was established to validate the proposed autolysis kinetic equations. The autolysis rate of products with molecular weight < 3,000 Da increased rapidly from 0 hr to 3 hr. The aliphatic amino acids showed a higher amount release than that of other amino acids during the autolysis. The amounts of released heterocyclic amino acids (Trp and His) were also much more than that of other amino acids.

An Exochitinase with N-Acetyl-β-Glucosaminidase-Like Activity from Shrimp Head Conversion by Streptomyces speibonae and Its Application in Hydrolyzing β-Chitin Powder to Produce N-Acetyl-d-Glucosamine.

Marine chitinous byproducts possess significant applications in many fields. In this research, different kinds of fishery chitin-containing byproducts from shrimp (shrimp head powder (SHP) and demineralized shrimp shell powder), crab (demineralized crab shell powder), as well as squid (squid pen powder) were used to provide both carbon and nitrogen (C/N) nutrients for the production of an exochitinase via Streptomyces speibonae TKU048, a chitinolytic bacterium isolated from Taiwanese soils. S. speibonae TKU048 expressed the highest exochitinase productivity (45.668 U/mL) on 1.5% SHP-containing medium at 37 °C for 2 days. Molecular weight determination analysis basing on polyacrylamide gel electrophoresis revealed the mass of TKU048 exochitinase was approximately 21 kDa. The characterized exochitinase expressed some interesting properties, for example acidic pH optima (pH 3 and pH 5–7) and a higher temperature optimum (60 °C). Furthermore, the main hydrolysis mechanism of TKU048 exochitinase was N-acetyl-β-glucosaminidase-like activity; its most suitable substrate was β-chitin powder. The hydrolysis experiment revealed that TKU048 exochitinase was efficient in the cleavage of β-chitin powder, thereby releasing N-acetyl-d-glucosamine (GlcNAc, monomer unit of chitin structure) as the major product with 0.335 mg/mL of GlcNAc concentration and a yield of 73.64% after 96 h of incubation time. Thus, TKU048 exochitinase may have potential in GlcNAc production due to its N-acetyl-β-glucosaminidase-like activity.

Effects of Shrimp Waste Types and Their Cooking on Properties of Extracted Astaxanthin and Its Characteristics in Liposomes

This study was aimed to evaluate the effects of shrimp waste types (fresh head, cooked head, fresh shell and cooked shell) and of cooking these wastes on the properties of astaxanthin. The astaxanthin was subject to liposomal encapsulation and its characteristics were determined. Astaxanthin was extracted from fresh and cooked (90°C for 15 min) materials, and then yield, astaxanthin content, antioxidant activities (DPPH and ABTS scavenging assays) and fatty acid profiles were determined. Phospholipid was used at various concentrations (2, 3 and 4 % w/v) to prepare astaxanthin-loaded liposomes, which were further evaluated for particle size, zeta potential, antioxidant activity (DPPH scavenging assays) and outer structure by confocal laser scanning microscope. The results showed that fresh shrimp heads gave the highest percent yield (30.49 mg extract/g raw material), but the highest astaxanthin content was found in fresh shrimp shells (14.65 mg/g). Shrimp heads and shrimp shells, both fresh and cooked, were significantly different (p<0.05) in terms of their antioxidant activity (based on DPPH and ABTS scavenging assays). Three fatty acids, palmitic acid, oleic acid and linoleic acid were most abundant and found in all samples. However, extract from fresh shrimp shells showed the highest EPA and DHA content of 10.48 % and 11.62 %, respectively. Astaxanthin-loaded liposomes derived were different in size in that the higher concentration, the larger liposomes produced. Liposomes prepared from 4% (w/v) phospholipid at 50 amplitude gave the highest %DPPH scavenging activity of 79.23.

Conversion of Shrimp Head Waste for Production of a Thermotolerant, Detergent-Stable, Alkaline Protease by Paenibacillus sp.

Fishery processing by-products have been of great interest to researchers due to their beneficial applications in many fields. In this study, five types of marine by-products, including demineralized crab shell, demineralized shrimp shell, shrimp head, shrimp shell, and squid pen, provided sources of carbon and nitrogen nutrition by producing a protease from Paenibacillus sp. TKU047. Strain TKU047 demonstrated the highest protease productivity (2.98 U/mL) when cultured for two days on a medium containing 0.5% of shrimp head powder (SHP). The mass of TKU047 protease was determined to be 32 kDa (approximately). TKU047 protease displayed optimal activity at 70–80 °C and pH 9, with a pH range of stability from 6 to 11. TKU047 protease also showed stability in solutions containing surfactants and detergents. Based on its excellent properties, Paenibacillus sp. TKU047 protease may be a feasible candidate for inclusion in laundry detergents.

Feed preference and growth response of juvenile Litopenaeus vannamei to supplementation of marine chemoattractants in a fishmeal‐challenged diet

AbstractThis study compared the feed preference and growth response of Litopenaeus vannamei to chemoattractants. A diet with 3% fishmeal was supplemented with either 3% salmon meal (POS), 3% soy protein concentrate (NEG), 3% krill meal (KRM), 3% squid meal (SQM), 3% shrimp head meal (SHM), 3% shrimp meal (SM), 3% squid liver meal (SLM), or 5% liquid sardine hydrolysate (SAH). Shrimp with a body weight (BW) of 0.99 ± 0.08 g were stocked at 100 animals/m2 in 56 tanks of 1 m3 and fed 10 times daily for 74 days. Feed preference was evaluated by feeding shrimp of 10.87 ± 1.82 g in excess twice a day for 10 days in two separate feeding trays allocated in 50 tanks of 0.5 m3. Survival reached 93.3 ± 5.80% and was unaffected by supplementation. Final BW was the highest for shrimp fed the KRM‐supplemented diet (11.97 ± 0.93 g), followed by POS (11.11 ± 0.77 g) and SQM (11.01 ± 1.17 g). Diets SHM, SM, SLM, and NEG showed a lower shrimp BW than POS, but were not statistically different among them. Shrimp fed the SAH diet achieved the lowest BW (10.06 ± 1.02 g). The highest gained yield was obtained with diets KRM and POS. No statistical difference was observed in shrimp yield among other diets. The lowest feed conversion ratio (FCR) was achieved with shrimp fed KRM (1.31 ± 0.05) when compared to diets SHM (1.47 ± 0.05), SAH (1.47 ± 0.07), and SLM (1.45 ± 0.17). Two‐by‐two comparisons indicated that shrimp preferred SHM and KRM, except when these were compared to SQM and SLM. No difference in feed preference was found between diets with SQM and SLM. SAH was the least preferred raw material in all comparisons. Results indicated that KRM acts as a powerful feeding effector and growth enhancer in fishmeal‐challenged diets for whiteleg shrimp. A dietary supplementation with 3% KRM is more effective than the same dose of any other chemoattractant evaluated.