Catfish Feed Research Articles

Effect of Drying Parameters on the Physical Properties of Extruded Fish Feed

Commercial catfish feed is sometimes manufactured through extrusion, usually are of high moisture content which cannot be stored or transported without it being damaged, hence, the need for effective drying of fish feed. Fish feed was formulated, mixed, extruded (single screw extruder), dried (mechanical convective dryer) and evaluated upon to examine the impact of the drying parameters (air drying temperature and air-drying velocity) and some physical properties of the fish feed. Five levels of drying air temperature (40° C, 50° C, 60° C, 70° C and 80° C) and three levels of drying air velocity (1.0 m/s, 1.5 m/s and 2.0 m/s) were used during the drying experiments. The final moisture content reduces with increase in drying air temperature and drying air velocities. The drying temperature does not significantly affect the unit density and porosity. Bulk density reduces with increased drying air temperature and drying air velocity. The extrudate porosity increases with drying air temperature. The drying air velocities does not significantly affect the sinking velocity and porosity. The optimum floatation time is from the feed dried at 1.5 m/s drying air velocity and 80oC drying air temperature.

Sunflower meal with and without phytase supplementation in diets for silver catfish (Rhamdia quelen) juveniles

Background: The cost of feed in fish farming can exceed 70% of the total costs. Thus, the feed industry have sought to formulate balanced diets including low-cost by-products. Objective: To evaluate sunflower meal as a partial substitute (0, 10, and 20%) for soybean meal, with or without phytase supplementation (1,500 FTU/kg) in isoproteic (27% crude protein (CP)) and isoenergetic diets (3,400 kcal/ED/kg of feed) for silver catfish (Rhamdia quelen) juveniles. Methods: A total of 360 fish (weight: 15.77 ± 0.56 g) were randomly distributed in 24 tanks in a completely randomized design following a factorial scheme (3x2) with 4 replicates. The fish were evaluated on the following variables after 90 days: productive performance, hematological variables, histology of intestinal tissue, bromatological composition of carcass, and composition of bone mineral matter. Results: 20% dietary inclusion of sunflower meal improved weight gain and protein efficiency. No difference was observed in the other treatments and no interactions were observed between the other factors. Conclusion: 20% sunflower meal can be included in the feed of silver catfish as a substitute for soybean meal. Phytase inclusion (1,500 FTU/kg) did not improve the nutritional value of the treatments.

EFFECT OF DIETARY FERMENTED LAMTORO (Leucaena leucocephala) LEAVES FLOUR IN FEED ON DIGESTIBILITY AND HEMATOLOGICAL PARAMETERS OF CATFISH (Clarias sp.)

Leucaena leaves is a potential ingredient for raw material feed of catfish. The aim of this study is to evaluate the effects of dietary fermented leucaena leaf on digestibility and hematological parameters of catfish. Four treatments and 3 replicates, namely: A (reference feed 70% + leucaena leaves meal 30%), B (reference feed 70%+fermented leucaena leaves meal with A. niger 30%), C (reference feed 70%+fermented leucaena leaves meal with R. oligosporus 30%), and feed D (reference feed 70%+fermented leucaena leaves meal with S. cerevisiae 30%) were used in this study. The juvenile catfish (initial weight was 5,45±0,16 g) are randomly distributed into eighteen tanks with 40 fish per aquarium. Each diet is randomly assigned to the triplicate aquarium and fed to fish three times a day up to satiation for 4 weeks. The results showed that fermented leucaena leaves treatments were significantly higher (P<0.05) than that control in final weight and feed conversion rasio. Nutrients digestibility and final weight were significantly highest (P<0.05) in fermented leucaena leaves with A. niger compared to the other treatment. The value of protein digestibility was significantly highest (P<0.05) in fermented leucaena leaves with A. niger (76,04%), followed by fermented leucaena leaves S. cerevisiae with (69,71%), fermented leucaena leaves meal with R. oligosporus (68,24%), and control (65,18). Leucaena leaves had no effect on physiological processes in catfish, as shown by hematological parameter values that were within the normal range.

Pemanfaatan ampas tahu dan eceng gondok sebagai pakan lele pada kolam terpal di Dusun I Desa Lubuk Siam Kecamatan Siak Hulu Kabupaten Kampar, Riau

Kegiatan pengabdian kepada masyarakat ini tentang Pemanfaatan Ampas Tahu dan Eceng gondok Sebagai Pakan Lele pada Kolam Terpal yang telah dilakukan di Dusun I Desa Lubuk Siam Kecamatan Siak Hulu Kabupaten Kampar, Riau dalam bentuk kegiatan penyuluhan dan pelatihan. Tujuan dari kegiatan ini adalah untuk memberikan pengetahuan dan penerapan teknik pembuatan pakan lele dari ampas tahu dan eceng gondok yang difermentasi dengan EM4 untuk budidaya ikan lele pada kolam terpal. Pada pelaksanaan kegiatan penyuluhan menggunakan metode ceramah, diskusi, dan demonstrasi. Sasaran dari penyuluhan ini adalah petani ikan/mitra dan masyarakat Dusun I Desa Lubuk Siam. Hasil dan ketercapaian sasaran mendapatkan solusi mengatasi permasalahan biaya pakan lele dan lamanya jangka waktu produksi/panen (± 6 bulan) dalam usaha budidaya yang dilakukannya menjadi ±3,5 meminimalisir biaya pakan dari Rp.17.000-Rp.20.000/kg menjadi Rp.3.000-Rp.5.000/kg, jadi menghemat biaya pakan ikan sebesar 50-60%. Kegiatan Pengabdian ini mendapat respon positif dari Kepala Desa dan perangkat desa, serta masyarakat Desa Lubuk Siam. Upaya pemberdayaan masyarakat Desa Lubuk Siam ini, dapat dilihat bahwa mitra sudah berhasil membuat pakan sendiri, menambah pendapatan mitra untuk kolam ukuran 10 m x 16 m dengan padat tebarnya 25.000-30.000 ekor sebesar Rp.3.000.000-Rp.4.000.000/bulan dan meningkatkan gizi keluarga.

IMPLEMENTATION OF SCIENCE AND TECHNOLOGY IN FEED PRODUCTION TOWARDS SELF-SUPPORTING CATFISH LIVESTOCK

Feed is the main key to success in small and large scale catfish farming. If we keep catfish in a large scale, we must be smart to make feed management, of course. It is undeniable that many catfish farmers failed and went bankrupt because they did not know the correct technicalities in catfish farming. Where production costs in catfish cultivation are almost 70% in feed management.
 One alternative that can be done to reduce production costs is to make homemade feed through simple techniques by utilizing local sources of raw materials (including the utilization of agricultural industrial waste) which is relatively cheap. In addition to meeting their own needs, the artificial feed produced can also be sold to markets / other fish farmers so that it can provide multiple benefits. It is not an easy matter indeed to make fish feed itself, it requires special skills to be able to practice it themselves. Farmers must understand what content must be contained in the fish feed.
 In connection with this, it is deemed necessary to provide training in making their own catfish feed through simple techniques. It is also necessary to provide guidance and training that enables partners to calculate total sales revenue and total costs so that they are able to find out how much profit is earned per month.
 It is expected that after mentoring, partners will become more knowledgeable and able to apply it in their daily work. Thus partners will be more developed, become more economically independent, increase income, become more productive and become more optimistic in their efforts so that the entrepreneurial spirit is built.

EFFECTS OF DIETARY PROBIOTIC Bacillus NP5 ON THE GROWTH PERFORMANCES OF CATFISH (Clarias sp.)

Probiotic have long been applied to aquaculture and produce positive effects on fish and shrimp. This research aimed to evaluate the effect of probiotic Bacillus NP5 to promote the growth of catfish (Clarias sp.). Five doses Bacillus NP5 with 3 replicates, namely 0% probiotic (control), 0.5 % probiotic, 1% probiotic, 1.5% probiotic and 2% probiotic (g/100 g feed) were used. The result showed that application of probiotic in catfish feed can promote better growth performance compared to control. Total digestibility and protease enzyme activites were significantly highest in 1% probiotic. The value of specific growth rate showed in 1% probiotic (2.67±0.18% day-1), followed by 2% probiotic (2.63±0.02% day-1), 1.5% probiotic (2.42±0.07% day-1), 0.5% probiotic (2.29±0.14% day-1) and control (1.60±0.01% day-1). The addition of 1% Bacillus NP5 as probiotic in catfish feed showed the best result on protease enzyme activities, protein digestibility, total digestibility, final weight, specific growth rate, weight gain, feed efficiency and, the protein efficiency ratio than other probiotic doses.

Effects of Density on Production of Hybrid Catfish in Intensively Aerated Earthen Ponds where Dissolved Oxygen is Not a Limiting Factor

AbstractResearch has demonstrated that by maintaining the minimum dissolved oxygen (DO) concentration in earthen ponds at or above 3.0 ppm, feed intake and growth of Channel Catfish Ictalurus punctatus, Blue Catfish I. furcatus, and hybrid catfish (female Channel Catfish × male Blue Catfish) may be doubled relative to those achieved with the oxygen management regimes typically used on commercial catfish farms. In earlier studies using only emergency aeration or low levels of fixed aeration, the direct effect of stocking rate has been confounded by lower morning DO concentrations in ponds stocked at higher densities due to higher feed input and fish biomass. Although higher stocking rates in those studies did produce greater yields, individual fish growth and feed intake may have been impacted by lower DO levels while appearing to be a direct density effect. In this study, production of hybrid catfish, which were fed daily to satiation in earthen ponds with no water exchange, was compared at low (5,000 fish/acre) and high (20,000 fish/acre) stocking rates while using controlled intensive aeration to maintain a minimum DO over 3.0 ppm in all ponds through the study. We achieved an average net production of 27,704 lb/acre at the higher stocking rate compared to 10,176 lb/acre at the lower stocking rate. Although this is the highest yield reported thus far in traditional static‐water earthen ponds in the southern USA, it may not be the maximum production possible. The average weight of harvested fish was higher at the lower density (2.2 lb versus 1.6 lb), but the feed conversion ratio was identical (1.8) at the two densities. Our data indicate that when morning DO is maintained above limiting concentrations, other factors such as direct density interactions (aggression and/or inhibitory pheromonal feedback) and/or water quality variables unrelated to morning DO—specifically un‐ionized ammonia—may play a role in catfish feed intake and growth but not food conversion.

The Application of Probiotics for the Purpose of Growing Catfish (Clarias batrachus) in Malumbi Village, East Sumba

The community service activity reported in this paper was conducted in Malumbi Village, East Sumba Regency, East Nusa Tenggara. The target of this community service was the Tani Tunas Baru group and the Malumbi Farmer group. The purpose of this service was to provide knowledge and information to these two farmer groups about good and correct fish farming techniques and the application of EM-4 probiotics as feed for catfish. The activity consisted of two, namely workshop and mentoring. The service provided new knowledge and insight to the two farmer groups. The farmers were shown activities such as preparation for maintenance ponds, fertilization techniques, seed spreading techniques in new containers, good and correct feeding techniques, and water replacement systems car. In addition, assistance related to probiotic applications was also implemented. The results showed that the administration of probiotics EM-4 gave good results on the growth rate and survival of the catfish each by 18% and 80% when compared to controls. It is hoped that fish farmers in the Tunas Baru and Malumbi groups are able to apply the knowledge that they have learned.

PEMANFAATAN FERMENTASI REMPAH-REMPAH SEBAGAI CAMPURAN PAKAN LELE

The business of Catfish Farmers (PIL) has become increasingly restless because of the high price of catfish feed in the market. Seeing the progress that is progressing, the increasing number of PILs will bring new problems to thelocalgovernment.Moreover,whatisfacedinthePILproblemisthereducedqualityofcatfishfeed. The purpose of this study was to determine the proximate protein content by using a proximate test on catfish feedderivedfromspicefermentationcombinedwithpapayafruitandstarchaddedwithcanetreacle. A total of 9 compositions of spices used in this fermentation, turmeric 0.5 kg, laos 0.5 kg, key 0.5 kg, kencur 0.25 kg, temulawak 0.5 kg, molasses 0.5 kg, betel leaf 0 , 25 kg, temuireng 0.25 kg, ginger 0.25 kg and 0.5 kg blimbing, 1 kg papaya plus sugarcane drops 1.5 liter and IM4 0.5 kg. Seteleh milled the composition of fermented spices to produce 35 liters of fermented liquid, then added 40 liters. The liquid spice mixture is stored for15daysinavessel,the fermentationprocessofcatfishfeedbeforeconsumptiontakes1 day.Fromthe results ofthestudythatthecontentoffermentedproteinwithspicesofsugarcanedropsof31.39%withaconversionof 32.41%incatfishfeedcanincreaseproteinlevelsincatfishfeed.

The Use of Mannan-oligosaccharide (MOS) to the Growth and Survival Rate of Java Eel (Anguilla b. bicolor)

Growth and survival rate are the most crucial in commercial culture as well as feed quality, and it’s pricing. This study aimed to obtain the effect of different dose of MOS to the growth and survival rate early big pencil size of shortfin eel Anguilla b. bicolor. Three replications with four treatments of feed containing 0, 0.1, 0.2, and 0.3 % doses of MOS (noted as T0, T1, T2, and T3) were administered during 84 days culture. The fish were fed with 2.2% wet basis d-1 of commercial shrimp feed combined with catfish feed. Initial density of approx. 5 kg seed stock of early big pencil eel in 0.4 m3 recirculating water system. The result indicated that absolute, individual and biomass-specific growth rate (SGRi/b) have the similar patterns corresponds to the dose of MOS. The highest SGRi was T3 (0.69±0.05% d-1) followed by T2 (0.60±0.03% d-1), T1 (0.46±0.04% d-1) and T0 (0.44±0.03% d-1). Meanwhile the SGRb shows significantly different (α < 0.05) between T3 (0.66±0.05% d-1) and T2 (0.57±0.04% d-1), but no significantly different (α > 0.05) between T1 (0.43±0.05% d-1) and T0 (0.40±0.02% d-1), and both of T3 and T2 have significantly different (α < 0.01) to T1 and T0. The best SR was in T2 (98.0 %), followed by T1 (97.5 %), T3 (97.3 %) and T3 (96.4 %). Hence, the MOS gave a positive impact on growth and slightly gave a different effect on survival rate.

Antibacterial activities of trans-cinnamaldehyde, caprylic acid, and β-resorcylic acid against catfish pathogens

Bacterial pathogens such as Edwardsiella ictaluri, Flavobacterium columnare, and virulent Aeromonas hydrophila have a significant economic impact on farm-raised catfish in the United States. Due to the limited number of licensed vaccines, and regulations with antimicrobials usage, there is need to find alternative therapeutics for sustainable aquaculture. Therefore, the antibacterial activities of trans-cinnamaldehyde (TC), caprylic acid (CA), and β-resorcylic acid (BA) were assessed against E. ictaluri 93–146, F. columnare 94–081, and A. hydrophila ML09–119 using broth microdilutions, and the capacity of TC to prevent E. ictaluri infection was evaluated during a challenge trial. Results demonstrated that TC inhibited growth of E. ictaluri, F. columnare, and A. hydrophila at 40, 20, and 80 μg/ml. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) of E. ictaluri, F. columnare, and A. hydrophila after incubation with TC revealed cell wall lysis, leakage of cytoplasmic contents, and pleomorphism in the bacterial shape with rupture of outer membranes. By the histological analysis, no abnormal changes were observed in the catfish intestines as a result of supplementation of TC. Moreover, an increasing number of goblet cells was observed in catfish received TC compared to control. In the E. ictaluri challenge trial, significantly higher survival was found in catfish that received TC at the levels of 15 and 20 mg/kg compared to control group (49.12% and 65.52% survival vs 11.11% survival). Bacterial concentrations in spleen and anterior kidney were significantly (P < .05) lower in fish fed with TC (20 mg/kg diet) compared to control at 5-day post-infection. Results indicate that supplementation of catfish feed with TC reduces E. ictaluri infection. A safe and efficacious alternative to antimicrobials will reduce the emergence and spread of antimicrobial resistant strains.

Growth and digestive enzymes of silver catfish fed diets containing fruit residue

ABSTRACT In fish farming, the use of alternative ingredients has been studied, so that alternative sources can be used to minimize feed costs. This study evaluated the incorporation of grape, orange, guava, and fig residues in diets for silver catfish and its effects on growth, digestive enzymes and body composition. A total of 180 fish (initial mean weight = 22.93±0.75 g) were reared in a recirculation aquaculture system. There was no difference (P&gt;0.05) in the parameters of growth, dry matter, mineral matter, plasma protein, cholesterol, triglycerides, lipase, and trypsin of fish. Glucose levels were higher in fish fed diets containing fig, orange, and grape residue (P&lt;0.05). Lipase activity was higher in fish fed orange residue, compared to guava (P&lt;0.05). Diets containing guava and fig provided more body protein in silver catfish. The fish fed with diet containing orange residue had a higher content of body lipids. It can be concluded that the tested fruit residues can be used in silver catfish feeding.

PENGARUH SUBSTITUSI TEPUNG IKAN DENGAN TEPUNG KEPALA IKAN PATIN (Pangasius sp) TERHADAP PERTUMBUHAN IKAN LELE SANGKURIANG (Clarias sp)

ABSTRACTThe research was conducted at the Aquaculture Laboratory, University of Lampung in May to July, 2018. The aim of this study is to determine the effect of substitution of fish meal with catfish head flour on the growth of catfish, and head flour dosage the best for catfish growth. The study used a Completely Randomized Design with 3 treatments and 3 replications A (100% fish meal), B (70% fish meal and 30% catfish flour), and C (40% fish meal and 60% catfish flour). Parameters observed included absolute growth, daily growth rate, protein retention, feed convertion ratio (FCR), survival rate (SR), and supporting parameters that is feed cost and water quality. The data obtained were analyzed by variance and continued with smallest real difference test with a 95% confidence level. The results showed that the proportion of catfish head flour in artificial feed had an effect on absolute weight growth and daily growth rate (P, 0.001). The proportion of the use of 30% starch in the feed of catfish has a real influence on absolute growth (40.25 ± 5.67 g), and daily growth rate (0.67 ± 0.09 g/day).Keywords : Catfish, catfish head waste, substitution, feed, growth

The Effect of Various Probiotics in Sangkuriang Cat Fish (Clarias gariepinus) on Health Status and Performans Production

Probiotics are very important for cultivation because of their role in improving the health status of fish, increasing the body's resistance to disease, growth rate, improving intestinal morphology and balance of the microflora. The study aimed to compare commercial probiotics with probiotics from fermented milk using kefir seeds in an effort to improve health, growth rate and efficiency of sangkuriang catfish feed. The research material used 5-7cm long sangkuriang catfish as many as 400 tails. The study used a completely randomized design (CRD) with 4 treatments and 5 replications, namely P0:Control (feed without addition of probiotics), P1: Feed + 5% Probiotics A (King Grameh), P2: Feed + 5% Probiotics B (Em4), P3: Feed + 5% Probiotics C (Kefir). Each experimental unit consisted of 20 fish. The parameters observed in this experiment were growth rate, FCR and feed efficiency. Treatment with various types of probiotics has a significant effect (P &lt;0.05) on FCR, feed efficiency, and growth rate. However, the FCR in treatments T1 and T2 did not show significant differences, and on feed efficiency and growth rate on T1 were not significantly different. The conclusion of this study is that the provision of kefir probiotics is able to show better production results.

Sardine (Sardinella spp.) protein hydrolysate as growth promoter in South American catfish (Rhamdia quelen) feeding: Productive performance, digestive enzymes activity, morphometry and intestinal microbiology

This study evaluated the effects of dietary inclusion of sardine (Sardinella spp.) protein hydrolysate (SPH) on productive performance, digestive enzymatic activity, morphology and intestinal microbiology of South American catfish (Rhamdia quelen) juveniles. SPH was produced from sardine processing wastes using Protamex® protease complex from Novozymes A/S. Four levels of inclusion were evaluated (0, 2, 5 and 10%). A total of 480 South American catfish juveniles (average weight 11.3 ± 2.46 g) were distributed in 24 polyethylene containers, in a completely randomized design with four treatments and six replications. The fish were fed twice daily until apparent satiation with isoproteic (39%) and isoenergetic (4376 kcal.kg−1) diets for 56 days. Regardless of the SPH inclusion levels in the diets, average weight gains (36.28 g), specific growth rate (2.56% day−1), apparent feed intake (40.51 g) and apparent feed conversion rate (1.12) were improved when compared to the control treatment (average of 24.95 g; 2.11% day−1; 31.00 g and 1.28, respectively). Total alkaline protease activity of the gastrointestinal tract of the South American catfish juveniles was higher in the treatment that received 5% SPH (0.61 ± 0.23 U. mg−1 of protein) than in the control (0.26 ± 0.08 U.mg−1 of protein). The amylase activity was higher in the treatments with 2% SPH (1.58 ± 0.19 U. mg−1 of protein) and 5% SPH (1.43 ± 0.44 U. mg−1 of protein) when compared to the control (0.40 ± 0.18 U. mg−1 of protein). In the 5% SPH treatment, higher amounts of lactic acid bacteria and Vibrionaceae were detected than in the other treatments. No difference was found for total heterotrophic bacteria. There was no difference in the intestinal morphometry of the South American catfish for any one of the analyzed parameters. Inclusion levels of up to 10% SPH in the diets of South American catfish showed improvement in the productive performance and nutritional efficiency, acting as a growth promoter. The inclusion level of 5% SPH caused an increase in the digestive enzymatic activity and populations of intestinal lactic acid bacteria. Thus, a prebiotic effect on the fishes was observed and the inclusion level may determine the effects of SPH.

Levels of pesticide residues in water, sediment, and fish samples collected from Nile River in Cairo, Egypt

Pesticides constitute one of the major sources of environmental hazards to human and animals as they concentrate in the food chain. Organochlorine, organophosphorus, and carbamate pesticides were investigated using water, sediment, and fish (Clarias gariepinus, Oreochromis niloticus, and Tilapia zillii) muscle samples of the Nile River in Cairo region (Egypt). Pesticide residues were analyzed seasonally using gas chromatography. The results showed that the average total pesticide residue in sediment was higher (63.5 ± 36.2 ppb) than that in water samples (45.1 ± 35.0 ppb). High levels of total pesticide residues in water and sediment samples were detected in autumn (73.57 ± 62.97 and 103.03 ± 16.05 ppb, respectively), which may be attributed to the increase in suspended matter (low flood) and high application of pesticides during that season. Pesticide residue in tissue samples of C. gariepinus amounted to 49.1 ± 17.8 ppb followed by T. zillii (48.3 ± 18.9 ppb) and O. niloticus (45.6 ± 28.7 ppb). The relatively high levels of total pesticide residue on C. gariepinus tissue may be explained by the nature of catfish habits and feeding. The estimated pesticide residual concentrations in fish samples did not exceed the maximum residue limits. Health risk estimation revealed that all tested pesticides in the studied fish species had no potential for systemic toxicity to consumers, but regular monitoring is recommended to control the levels of pesticide residues in the Nile River ecosystem.

Budidaya Ikan Lele Organik Dan Diversifikasi Produk Olahan Abon Ikan Lele

The purpose of this IbM activity is to disseminate the technology of organic catfish farming and organic catfish abon (shredded meat that has been boiled and fried/meat floss) in Jetak Asri Farmer Group in Mulyo Agung Village and Pesantren Darul Madhinah in Mulyorejo, Junrejo, Kota Batu. Application of organic catfish farming technology and diversification of processed products of organic catfish are expected to help increase the income of catfish farmers. The method used in this activity is to involve the community directly. Implementation of activities in the form of socialization, counseling, and training on how to cultivate organic catfish and making organic catfish abon. Organoleptic test results show that the abon made from organic catfish has the advantage of texture, taste, color that's better than the abon made from catfish are bought in the market. The obstacles faced by catfish farmers still depend on the catfish feed production plant, and the cost of feed is a very high component in the cultivation of catfish.

PENGARUH SUBSTITUSI DEDAK DENGAN TEPUNG AMPAS KELAPA TERFERMENTASI TERHADAP PERTUMBUHAN DAN EFISIENSI PAKAN IKAN PATIN (Pangasius sp.)

ABSTRACTCoconut dregs is waste from coconut milk production. The purpose of this study was to determine the effect of fermented coconut dregs feeding on the growth and efficiency of catfish feed and to know the exact percentage in feed formulation on catfish. This research was conducted from November to December 2017 at Aquaculture Laboratory of Aquaculture Study Program, Faculty of Agriculture, Sriwijaya University. This study used a complete randomized design with 5 treatments and 2 replications. The treatment was used the difference of percentage of the fermented coconut dregs flour in the formulation of 0%, 5%, 10%, 15% and 20%. Data to be collected include growth, survival, feed efficiency, formulated analysis of each treatment consisting of water, ash, protein, fat, carbohydrate, and crude fiber and water quality. The result of this research showed that the absolute growth of lengthy P4 is 0.54 cm, the absolute growth of weight P4 is 1.42 g, the best feed consumption in P0 with total feed consumption is 3.43 g.individu-1, feed efficiency P4 is 47.82% and survival rate P4 is 87.50%. Water quality during research were still optimum for catfish with temperature 26.0-29.0oC, pH 6.5-8.1, DO 4.57-8.86 mg.L-1 and ammonia 0.003-0.02 mg.L-1. Keywords: Catfish, Coconut dregs, Feed efficiency, Fermentation, Growth

Pengembangan Pakan Ikan untuk Menekan Biaya Produksi Budidaya Lele

DEVELOPING IN FISH FEED FOR SAVING PRODUCTION COSTS OF CATFISH CULTIVATION. Making catfish feed from waste raw materials and the surrounding environment in order to save production cost. The growth of fish depends on the feed intake, but this is not sufficiently well due to the increase in feed prices. Therefore, it is necessary to innovate the production of feed that utilizes the natural resources around the surrounding waste. Development of fish feed to reduce costs by 4 ways i.e. fish feed with organic fertilization, utilization of Azzola plants or mini water spikes, organic feed from growing and the surrounding waste and artificial pellet feed with appropriate technology. Feeding innovation is expected to reduce the production cost of 70% which designate is feed. This devotion partner is a group of Mulyo Tani 1 and Orphanage group of orphanage son of Muhammadiyah Setrorejo, Baturetno. This devotion activity successfully developed catfish farming business by doing continuous feed development.

Feeding ecology of generalist consumers: a case study of invasive blue catfish Ictalurus furcatus in Chesapeake Bay, Virginia, USA

Globally, invasive species cause extensive economic damage and are a major threat to biodiversity. Generalist species are particularly dangerous invaders, as they can thrive in degraded habitats and endure environmental stochasticity, often outcompeting more specialized native taxa. Blue catfish Ictalurus furcatus were first introduced into the Chesapeake Bay during the 1970s, and now form dense populations in several tidal rivers. Despite being labeled as a dangerous invasive, the feeding ecology of this species is largely unknown. We used a stratified random design to collect stomachs from 16,110 blue catfish in tidal freshwater, oligohaline, and mesohaline segments of the James, Pamunkey, Mattaponi, and Rappahannock Rivers. Indices of diet breadth and omnivory reveal that blue catfish are generalist omnivores with some of the highest diet breadths ever observed in an estuarine fish species, while trophic level calculations demonstrate that blue catfish are a mesopredator occupying lower trophic levels than previously claimed. Cumulative prey curves revealed that large numbers of stomachs are necessary to adequately characterize the diet of blue catfish, thus previous diet descriptions of this species should be considered with caution. Blue catfish feed primarily on invasive aquatic vegetation and Asian clams, though the economically-valuable blue crab Callinectes sapidus is also consumed regularly. While the per capita impact of blue catfish on imperiled native species appears to be low, this impact could still be substantial due to high population densities.