Channel Catfish Diets Research Articles

Dietary supplementation of mineral nanoparticles for channel catfish (Ictalurus punctatus).

This study evaluated the supplementation of iron and copper nanoparticles in channel catfish diets and their influences on growth and health. A comparative feeding trial was carried out for 9weeks to evaluate combinations of iron and copper nanoparticles: only iron nanoparticles (IronNP), only copper nanoparticles (CopperNP), CopperNP + IronNP, and a control diet supplemented with inorganic iron and copper (FeSO4 and CuSO4). After a 9-week feeding trial, growth performance, hematological parameters, whole-body proximate composition, and intestinal microbiota were evaluated, and fish were subjected to a bacterial challenge against Edwardsiella ictaluri to evaluate the contribution of the experimental treatments to fish health status. No statistical differences were detected for catfish fed the various diets in terms of production performance or survival after bacterial challenge. The hematocrit and RBC counts from fish fed the diet containing copper nanoparticles were significantly lower than the control group. A higher relative abundance of gram-positive bacteria was found in the digesta of catfish fed diets containing copper nanoparticles. Furthermore, in the context of hematology, iron nanoparticles did not impact the blood parameters of channel catfish; however, reduced hematocrits were observed in fish fed the copper nanoparticle diet, which lacked supplemental dietary iron, thus reinforcing the importance of dietary iron to catfish hematopoiesis. Nonetheless, additional studies are needed to investigate the effects of dietary copper nanoparticle supplementation in catfish diets to better illuminate its effects on the intestinal microbiota.

Exploring the nutritional value of corn fermented protein as a replacement for soybean meal in diets for juvenile channel catfish (Ictalurus punctatus): Impacts on production performance, intestinal health, and disease resistance

The use of corn fermented protein (CFP) can be a promising alternative ingredient to replace soybean meal (SBM) in aquafeeds, because of its attractive price and constant supply. In this study, the apparent digestibility of CFP was evaluated with channel catfish (Ictalurus punctatus), followed by a comparative feeding trial in which dehulled, solvent extracted SBM in the control diet was incrementally replaced with graded levels of CFP. A slight but significantly higher apparent protein digestibility coefficient was observed for SBM (91%) compared to CFP (89%). However, phosphorus and lipid were twice as available from CFP than SBM. A 60-day feeding trial was conducted, testing the gradual replacement of SBM by CFP on an equalnitrogen basis at 0, 25, 50, 75, and 100%. Channel catfish juveniles (∼11.6 g) were stocked in 30 aquaria (30 fish/ 110-L tank; n = 6) operating as a recirculating system and offered the experimental diets to apparent satiation twice daily. No differences were observed for hepatosomatic index, survival, or serum superoxide dismutase and lysozyme activities. Also, no treatment effects were observed for whole-body protein, ash, and protein conversion efficiency. However, weight gain, feed efficiency, intraperitoneal fat, and whole-body lipid were significantly affected by the dietary treatments with CFP able to replace up to 40 to 58% of the SBM in the diet while providing similar fish performance and body composition as fish fed the control diet. Digesta samples from the posterior segment of the intestine were subjected to DNA extraction, followed by 16S rRNA gene (V3-V4 region) sequencing to profile the intestinal microbiota. A higher relative abundance of Aeromonas spp. was observed for fish fed the control diet. The remaining fish from the feeding trial were challenged with Edwardsiella ictaluri, and cumulative survival was monitored for 21 days. Survival after the bacterial challenge gradually increased as the inclusion levels of CFP increased in the diets, with the 100% replacement treatment being significantly different from the control diet. In conclusion, CFP is a promising alternative plant protein ingredient with high protein and phosphorus digestibility, and it can replace up to 40 to 58% of the SBM in feed formulations for juvenile channel catfish based on weight gain and feed efficiency while potentially increasing disease resistance against E. ictaluri.

Diets of invasive channel catfish are subsidized by invasive riparian trees

AbstractRussian olive (Elaeagnus angustifolia) is an invasive, fruit‐bearing riparian tree that dominates riparian zones of the San Juan River in the southwestern United States. Previous research in this river suggests olive fruit is common in diets of invasive channel catfish (Ictalurus punctatus), but its energetic importance is unknown (i.e. critical for catfish fitness vs. incidental consumption). We assessed Russian olive consumption in channel catfish diets bimonthly for 1 year, hypothesizing that olive consumption would be greatest during periods of high olive availability and low benthic aquatic invertebrate availability. We found that catfish consumed olive fruit throughout the year and that olive comprised up to 44% of total stomach contents by mass, with peaks in spring and fall. Regression models revealed the presence and mass of olive fruit in catfish stomachs were positively associated with catfish total length, with a significant interaction between water temperature and river discharge. Catfish were more likely to consume olive fruit during higher flows, regardless of temperature and at low discharge with higher temperature. Contrary to our hypothesis, neither olive nor benthic invertebrate availability were associated with olive presence in channel catfish diets. Nutrition analysis indicated that olive alone was a low‐quality diet item but has the potential to provide a reliable energy source. We used seasonal data to estimate the energetic contribution of olive fruit to catfish populations using a bioenergetic model, which estimated that olive fruit accounted for 35.6% of energy (Joules) consumed by catfish populations and satisfied 38% of their metabolic demand. Our results suggest that Russian olive fruit is a significant subsidy to channel catfish in the San Juan River. However, more research is needed to determine the indirect effects of this interaction on native fishes and ecosystem function.

Investigation of dietary exogenous protease and humic substance on growth, disease resistance to Flavobacterium covae and immune responses in juvenile channel catfish (Ictalurus punctatus).

Many bacterial pathogens impact the US catfish industry, and disease control can be challenging for producers. Columnaris disease in channel catfish, Ictalurus punctatus, is primarily caused by Flavobacterium covae (formerly F. columnare). Immunostimulants may enhance nonspecific immune responses and offer an alternative to antibiotic treatments in catfish. Furthermore, dietary protein sources and inclusions are also essential to fish health and nutrition and may enhance overall fish performance in pond culture. The current project evaluated two immunostimulants: a protease complex (PC) and a humic substance (HS) derived from a reed-sedge peat product. A 60-day trial examined the effects of five diets on growth performance, immune response and resistance to experimental F. covae infection in channel catfish. Diets included a high-quality fishmeal diet (32%; CF32), a high-protein soy-based diet (32%; C32), a low-protein soy-based diet (28%; C28; predominately used in industry), a low-protein soy diet supplemented with C28 + PC at 175 g metric ton-1 and C28 + HS in a low-protein diet at 23 g metric ton-1 . Following feeding for 60 d, juvenile channel catfish were sampled for growth performance and baseline health indicators (n = 3; body mucus, blood for sera, kidney and spleen). A subset of fish was then subjected to an immersion-based in vivo challenge trial with F. covae (ALG-00-530; 106 CFU mL-1 exposure). At 60d post-initiation, there were no dietary differences in the relative growth rate (p = .063) or thermal growth coefficient (p = .055), but the 32% diets generally appeared to perform best. Post-challenge, the C32 group's mortality was higher than the C28 + PC (p = .006) and C28 + HS diets (p = .005). Although not significant, the C28 and CF32 groups also demonstrated higher mortality compared to both PC and HS diets. Sera lysozyme concentration was found to increase following pathogen challenge (p < .001) and in comparison with mock-challenged catfish (p < .001). Elevated expression levels of proinflammatory cytokines (il-1β, il-8, tnf-α and tgf-β) were observed at trial midpoint and post-infection when compared to 60d. The C28 treatment was found to have lower tnf-α expression than the C28 + PC (p = .042) and C28 + HS (p = .042) groups following exposure to F. covae. These challenge data suggest that the immunostimulants (PC and HS) in plant-based protein may be beneficial in protecting against F. covae when offered in low-protein channel catfish diets.

Elevated concentrations of organic and inorganic forms of iron in plant-based diets for channel catfish prevent anemia but damage liver and intestine, respectively, without impacting growth performance.

We compared the effects of using inorganic and organic forms of iron in plant-based diets on catfish performance in a feeding trial with 6-g catfish fingerlings. The objective was to determine whether dietary iron in excess of known requirements negatively affected the fish. Five diets supplemented with 0 (basal), 125, 250 mg Fe/kg of either FeSO4 or iron methionine were formulated. Weight gain, feed conversion ratio, hepatosomatic index, and survival were similar among diets. Plasma and intestine iron concentration was similar among diets. Whole-body total lipid, protein, and dry matter were similar among diets, while ash content was higher in fish fed the basal diet. Total liver iron concentration was higher in fish fed diets supplemented with 250 mg Fe/kg in both iron forms than other diets. Hematological parameters were similar among treatments. Liver necrosis, inflammation, and vacuolization were highest in fish fed the diet supplemented with 250 mg Fe/kg from organic iron, followed by those fed diets with 250 mg Fe/kg from inorganic iron. Inorganic iron-supplemented diets caused more intestinal inflammation (increased inflammatory cells, villi swelling, thicker lamina propria) than the organic iron-supplemented diets or basal diet. Organic iron at 250 mg/kg resulted in a $0.143/kg increase in feed cost. Latent iron deficiency and initial signs of anemia developed in catfish fed the basal diet. Supplemental iron from either form prevented iron deficiency. Organic iron at 125 mg/kg optimized fish performance at a cost comparable to that of fish fed other diets, but without overt negative effects.

Efficacy of crystalline amino acids supplementation in reduction of intact protein level in channel catfish Ictalurus punctatus diets

A 9-week growth trial was performed to assess the role of indispensable (IAA) and dispensable amino acids (DAA) supplementation in diets designed for juvenile (10.6 g) channel catfish (Ictalurus punctatus). The effects on fish growth, feed utilization, proximate, amino acids (AA) composition, and morphometric indicators were followed. Nine iso-lipidic (8 %) experimental diets were formulated with different levels of intact protein (32, 30, 28, 26, and 24 IP) supplemented with IAA (Lysine and Histidine) to restore IAA balance to those stated in NRC (2011). Additionally, DAA (Glutamic acid and Glycine) were added to the 24IP at different rates (2 %, 4 %, 6 %, and 8 %). At the conclusion of the growth trial, however, there was a linear decrease in fish growth as IP was lowered from 32% to 24%. But, based on mean separation; final mean weight (g), thermal growth coefficient (TGC), and feed conversion ratio (FCR) of channel catfish were not significantly different (P > 0.05) among fish groups fed diets containing 32 %, 30 %, 28 % and 26 % IP supplemented with IAA. Fish growth was significantly reduced, while apparent net protein retention (ANPR) and FCR significantly increased as IP was lowered to 24%. While growth and FCR of catfish fed 24IP with DAA (2–6 %) were not significantly different compared to catfish fed 32 % and 30 %IP diets. In conclusion, IAA (lysine and histidine) could be used as a supplement to reduce intact protein from 32 % to 26 % in channel catfish diets with maintaining IAA balance as recommended by NRC (2011). Catfish growth was improved by fortification of the 24IP diet with DAA (2–6 %), so the dietary IP level could be further lowered to 24 % with supplementation of IAA and DAA.

The Use of Poultry Corn By-Product Meal on the Growth Performance of Channel Catfish, Ictalurus punctatus

In this study, three growth trials were conducted to check the efficacy of poultry corn by-product meal, which was a combination of wet poultry processing waste and corn that was co-dried. It was relatively a new product, and its first growth trial was conducted in a laboratory (aquarium study) to evaluate the substitution of whole corn meal with poultry plus corn by-product meal (PCBM) in practical diets for channel catfish. In this trial (84 days culture period), 7 levels of PCBM (0, 5, 10, 15, 20, 25 and 30%) were evaluated in a practical diet containing 32% protein and 6% lipid. The results indicated that fish fed PCBM20 had the highest FW, WG and WG% among all the treatments, and these values were significantly higher (p &lt; 0.05) than at baseline or with PCBM5 treatment. The second trial (fingerlings to sub-market) was conducted in 12 raceways with 4 levels of PCBM (0, 10, 20 and 30%) and 600 fish (mean initial weight 42.3 ± 5.06 g) in each raceway. After 143 days of culture, the results demonstrated that there were no significant differences (p &gt; 0.05) between the FW, WG and WG% and the survival of the fish. To validate our results again, the third trial (sub-market to market) was conducted in 6 raceways with 2 levels of PCBM (0 and 30%). A total of 600 fish (mean initial weight 136.8 ± 6.3 g) were stocked in each raceway. The results revealed that there were no significant differences (p &gt; 0.05) between the FW, WG and WG% and fish survival after the culture period of 133 days. In all three trials, upon termination, the hepatosomatic index (HIS), the intraperitoneal fat (IPF), and the dress-out (headed and gutted) percentages were measured for trials 2 and 3. The results showed that there were no significant differences (p &gt; 0.05) between all these parameters except for HIS in trial 1 and IPF in trial 2 (p &lt; 0.05). In conclusion, PCBM can be used up to 30% in the diets of channel catfish.

Evaluation of Brewers Spent Grains with different levels of exogenous enzymes on the production performance and body composition of Nile tilapia (Oreochromis niloticus) and channel catfish (Ictalurus punctatus)

ABSTRACT This study evaluated Brewers Spent Grains (BSG) and an enzyme additive (AllzymeTM; ENZ) in practical diets for juvenile (~5 g/fish) Nile tilapia (Trial 1) and channel catfish (Trial 2). Following a factorial arrangement, effects of three dietary levels of BSG (0, 270, and 550 g/kg) and three levels of ENZ (0, 0.2, and 0.4 g/kg) on production performance and whole-body composition of the fish were evaluated. Upon conclusion of the feeding trials, no effects of ENZ, or interactions between BSG and ENZ, were found. Fish survival was >85% and unaffected by diet. Reduced growth of tilapia (from 949% to 778%) and catfish (from 1802% to 1364%) as dietary BSG increased from 0 to 550 g/kg were observed. In these trials, weight gain was reduced in both channel catfish and tilapia at BSG inclusion rates of ≥270 g/kg and that the addition of exogenous enzymes did not improve BSG utilization.

Evaluation of Peanut Meal as an Alternative Dietary Protein Source for Channel Catfish

AbstractUse of peanut meal as an alternative protein source in diets for Channel Catfish Ictalurus punctatus was evaluated in a 9‐week study under controlled laboratory conditions. Five practical diets (28% crude protein and 6% crude lipid) were formulated to contain 0, 10, 15, 20, and 25% peanut meal as a replacement for cottonseed meal and soybean meal in the control diet. The control diet was a plant‐based diet containing principally soybean meal (25%), cottonseed meal (20%), corn (20%), and corn germ meal (20%). All diets met or exceeded all known nutrient requirements of Channel Catfish. Twenty Channel Catfish fingerlings (mean initial weight: 12.8 g/fish) were stocked into 25 water flow‐through glass aquaria (110 L). The fish were fed once daily to apparent satiation. Among dietary treatments, there were no significant differences in feed consumption, weight gain, feed conversion ratio, and survival, and no differences in muscle protein, fat, or moisture levels. The results demonstrate up to 25% peanut meal can be used as a protein source alternative to cottonseed meal or soybean meal in Channel Catfish diets without adversely affecting growth, feed efficiency, and body composition.

Effects of Varying Levels of High‐Protein Distiller's Grains on Growth Performance of Channel Catfish, Ictalurus punctatus, and Post‐Extrusion Feed Pellet Characteristics

AbstractChannel catfish, Ictalurus punctatus, remains the USA's largest aquaculture industry. However, in recent years, high feed prices have negatively impacted profitability. Production of ethanol as a biofuel has increased dramatically. Companies have modified their processes to enhance ethanol yield and these modified processes also increase the crude protein content of the byproduct. The object of this study was to evaluate this high‐protein dried distiller's grains (HP‐DDG) for its suitability in catfish diets. A total of 25 full‐sibling channel catfish (7.1 ± 2.3 g) were randomly stocked into each of twelve 260‐L polyethylene tanks to achieve 25 fish per tank. The control diet was similar to a commercial formulation. Experimental diets contained 20, 40, or 40% HP‐DDG with added lysine (1% of total diet). There were three replicate tanks per diet. Fish were fed to apparent satiation twice daily for 9 wk. Average harvest weights for fish fed the 40% HP‐DDG diet without lysine supplementation (57.0 g) were significantly smaller than that for fish fed the control diet (77.7 g). Average harvest weights of fish fed 20% HP‐DDG (86.8 g) were significantly greater than that of fish fed either 40% HP‐DDG (57.0 g) or 40% HP‐DDG + lysine (73.7 g). There were no significant differences in feed conversion ratios or survivals among treatments, which overall averaged 1.1 and 99%, respectively. These data indicate that HP‐DDG appears to be a suitable ingredient in channel catfish diets up to at least 20% of the total formulation. Data also indicate that inclusion levels of at least 40% HP‐DDG are likely limiting in lysine.

Comparison of crystalline lysine and intact lysine used as a supplement in practical diets of channel catfish (Ictalurus punctatus) and Nile tilapia (Oreochromis niloticus)

The study was conducted using channel catfish and tilapia to evaluate the production performance of these fish to increasing levels of lysine from crystalline and intact lysine supplemented in practical diets. A practical lysine deficient basal diet was developed using corn protein concentrate (Empyreal® 75) as a primary protein source. To this diet either graded levels of crystalline lysine or similar levels from a high lysine corn protein concentrate (Lysto™) were added. In the channel catfish trial, the first five diets were designed to contain increasing levels of crystalline lysine (1.21%, 1.34%, 1.45%, 1.56%, and 1.72%) with an additional four diets using intact protein from a high lysine corn protein concentrate (1.40%, 1.57%, 1.77%, and 1.91% lysine). In the tilapia trial, lysine from two sources was added to 11 diets to produce analyzed lysine levels of 0.92%, 1.11%, 1.23%, 1.34%, 1.54% 1.65% in the first six diets using crystalline lysine and 1.13%, 1.38%, 1.61%, 1.81%, 2.02% in the last five diets using intact lysine. Results indicated that channel catfish and tilapia have positive performance with increasing lysine supplementation up to the requirement. Fish fed with the higher levels of lysine had the highest weight gain and lowest feed conversion ratio. The regression analysis on the increased level of inclusion of crystalline lysine and intact lysine showed no significant difference in slope. Based on the growth, feed conversion ratio and apparent net protein retention data obtained from this study, it can be concluded that the effectiveness of using intact lysine via high lysine corn protein concentrate as a lysine supplement is not significantly different from crystalline lysine. Thus, the high lysine corn protein concentrate is a feasible ingredient for aquaculture feeds, which can be used to balance the amino acid composition of the diet without addition of crystalline lysine. Statement of relevancePresent study shows that high lysine corn protein concentrate is a feasible ingredient for aquaculture feeds, which can be used to balance the amino acid composition of the diet without addition of crystalline lysine.

Age, Growth, and Fall Diet of Channel Catfish in Cheat Lake, West Virginia

Abstract Acidification has historically impaired Cheat Lake's fish community, but recent mitigation efforts within the Cheat River watershed have improved water quality and species richness. Presently, channel catfish Ictalurus punctatus are abundant and attain desirable sizes for anglers. We evaluated the age, growth, and fall diet of the population. We collected a sample of 155 channel catfish from Cheat Lake from 5 August to 4 December 2014, a subset of which we aged (n = 148) using lapillus otoliths. We fit four growth models (von Bertalanffy, logistic, Gompertz, and power) to length-at-age data and compared models using an information theoretic approach. We collected fall diets from 55 fish sampled from 13 October to 4 December 2014. Total lengths of individuals in the sample ranged from 154 to 721 mm and ages ranged from 2 to 19 y. We AICc-selected the von Bertalanffy growth model as the best approximating model, and the power and Gompertz models also had considerable support. Diets were numerically dominated by Diptera larvae, specifically Chironomidae and Chaoboridae, while 39% of stomachs contained terrestrial food items. This study provides baseline data for management of Cheat Lake's channel catfish population. Further, this study fills a knowledge gap in the scientific literature on channel catfish, because few previously published studies have examined the population ecology of channel catfish in the Central Appalachian region.

The Effects of Diets Containing Standard Soybean Oil, Soybean Oil Enhanced with Conjugated Linoleic Acids, Menhaden Fish Oil, or an Algal Docosahexaenoic Acid Supplement on Juvenile Channel Catfish Performance, Hematology, Body Composition, and Nonspecific Immune Response

AbstractTo reduce diet cost and address environmental concerns, current commercial diets for Channel Catfish Ictalurus punctatus contain little or no marine fish oil. However, there are conflicting data on the effects of fish oil and other lipid sources for juvenile Channel Catfish, and some novel lipids have not been tested against traditional ones. In this study, the effects of four different lipid sources for potential use in juvenile Channel Catfish diets were investigated by measuring fish growth performance, proximate and fatty acid composition of muscle, nonspecific immune response, and hematological parameters. In a 63‐d feeding trial, juveniles (mean weight ± SE = 11.2 ± 0.0 g) were fed a commercial 32% protein diet supplemented with 2% lipid from standard soybean oil (SBO; control diet), SBO enriched with conjugated linoleic acids (CLAs; CLA diet), algal (Schizochytrium sp.) docosahexaenoic acid (DHA) extract (DHA diet), or menhaden fish oil (MFO diet). Fish that were fed the MFO diet had improved feed conversion compared with fish that were fed the SBO, CLA, or DHA diet. There were no other differences in fish growth performance or proximate composition and no differences among treatments in nonspecific immune responses or hematological parameters. As expected, fatty acid composition of fish muscle reflected that of the diets: fish that received the MFO, DHA, or CLA diet contained higher levels of healthful fatty acids (DHA or CLAs) than fish that were given the SBO control diet. Future trials will address methods for (1) increasing target levels of these fatty acids by using diets with little or no fish oil and (2) optimizing retention of desirable fatty acids to facilitate the production of Channel Catfish as a high‐value functional food.

Effect of dietary Chinese tea on growth performance, disease resistance and muscle fatty acid profile of channel catfish (Ictalurus punctatus)

Six types of Chinese tea were incorporated into diets at four different levels (0, 1, 2 and 4 %) in order to determine their effects on the growth performance, fatty acid composition of muscle lipids and resistance to Aeromonas hydrophila infection of Ictalurus punctatus (channel catfish) fingerlings. Each diet was fed to catfish in triplicate tanks for 8 weeks. Results show that a 1 % Dragon Well tea (DWT) and Maofeng tea were significantly better than other diets (including the control) in improving weight gain (WG) and feed conversion rate (FCR) of fish; while the 4 % DWT increased FCR (P < 0.01) but decreased WG (P < 0.05). In addition, 4 % DWT resulted in a significant decrease in muscle lipid content. Pu-erh tea in 2 and 4 % dietary addition decreased saturated fatty acid and increased monounsaturated fatty acid content in muscle. The hepatosomatic index decreased significantly in fish fed the 4 % DWT diet. The mortality (%) of catfish challenged with A. hydrophila decreased with increasing addition of tea to the diet, and the mortality in DWT and Huangya tea (HYT) was lower than control groups (P < 0.05). In conclusion, diets supplemented with a low dose (1 %) of Chinese tea increased growth performance and enhanced the fish fillet quality. Addition of DWT or HYT tea at 4 % in channel catfish diets can improve resistance against A. hydrophila, but growth performance is reduced.

Use of Corn Germ Meal in Diets for Pond‐Raised Channel Catfish, Ictalurus punctatus

AbstractCorn germ meal (CGM) is a by‐product of corn milling. On the basis of its nutrient composition and digestibility values, it appears to be a suitable ingredient for use in channel catfish, Ictalurus punctatus, diets. A study was conducted to examine the use of various levels of CGM in diets for pond‐raised channel catfish. Four 28% protein diets containing 0, 15, 25, and 35% CGM were evaluated. Fingerling channel catfish (mean initial weight: 71 g/fish) were stocked into 24, 0.04‐ha ponds at a rate of 14,826 fish/ha. Fish were fed once daily to apparent satiation for a 167‐d growing season. No significant differences were observed in total amount of diet fed, diet consumption per fish, net yield, weight gain, feed conversion ratio, survival, fillet yield, and fillet protein, fat, and moisture concentrations among fish fed diets containing various levels of CGM. Carcass yield decreased linearly as dietary CGM levels increased. Depending on prices, CGM can be used interchangeably with corn gluten feed in channel catfish diets as replacements for corn, wheat middlings, and soybean meal to reduce feed cost.

Palatability of Diets for Channel Catfish that Contain Amprolium or Salinomycin Using Feed Conversion Ratio as the Criterion

AbstractTwo feeding studies were conducted to evaluate the palatability of diets for juvenile Channel Catfish Ictalurus punctatus that contained the poultry anticoccidial drugs Amprolium or Salinomycin, which are candidates to control the Channel Catfish myxozoan parasite, Henneguya ictaluri. These chemotherapeutic drugs can effectively control outbreaks of other myxozoan parasites in various species of aquaculture fish. To evaluate palatability of diets containing these drugs, Channel Catfish maintained in glass aquaria were fed sinking diets composed of commercial catfish feed that had been pulverized and reformed into pellets that contained three levels of each of the two anticoccidial drugs for short periods of time, e.g. 10 d for Amprolium and 8 d for Salinomycin. Results showed that fish readily consumed the basal control diet containing no drug and diets containing all three levels of Amprolium based on comparisons of feed conversion ratios (FCR) for the four dietary treatments. On the other hand, FCR values of the Salinomycin treatments were significantly (P &lt; 0.05) poorer for the two highest inclusion levels (30 and 60 mg/kg diet) of this drug compared with the control diet, which indicated poor palatability of diets containing these levels of Salinomycin by Channel Catfish.

Evaluation of Hydrolyzed Poultry Feathers as a Dietary Ingredient for Pond‐Raised Channel Catfish

AbstractThe present study examined the use of hydrolyzed poultry feathers (HPF) as a replacement for soybean meal in diets for pond raised Channel Catfish Ictalurus punctatus. Four isonitrogenous (28% crude protein) diets were evaluated that contained 0, 5, 10, or 15% HPF. Fingerling Channel Catfish (mean ± SD initial weight was 47.5 ± 2.2 g) were stocked into twenty 0.04‐ha earthen ponds at a rate of 14,830 fish/ha. Fish were fed once daily to apparent satiation for 140 d. No significant differences were observed for weight gain, feed conversion ratio (FCR), and survival among fish fed various levels of HPF. There were also no significant differences in net yield of fish fed diets containing 0, 5, and 10% HPF, but net yield of fish fed a diet containing 15% HPF was significantly lower than that of fish fed the control diet. Fish on diets containing 5% HPF and above were fed significantly less feed than fish fed the control diet. Regression analysis showed that total amount of diet fed, net yield, and weight gain decreased linearly as dietary HPF levels increased. Based on weight gain and net yield data, 5% HPF with supplemental lysine may be used in Channel Catfish diets without marked impact on fish growth performance. However, carcass and fillet yield were significantly reduced in fish fed diets containing 5% HPF and higher. Fillet protein generally decreased and fillet fat increased with increasing dietary HPF levels.

Effects of different dietary protein, lipid and digestible energy levels on growth and body composition of juvenile channel catfish(Ictalurus punctatus)

A 60-day feeding trial including diets with two protein levels(22%,28%),two lipid levels(10.0%,14.0%)and two digestible energy levels(12.56 kJ/g,14.23 kJ/g)designed with three replications was conducted to investigate the growth,nutrient utilization and body composition of juvenile channel catfish.Four hundred and eighty fish(initial weight,141.5±1.0 g)were randomly distributed into 24 tanks(3.0 m×0.8 m×0.8 m)at a rate of 20 fish per tank and fed three times daily.Fish were fed respectively to apparent satiation by experimental diets named P28L10E14.23,P28L14E14.23,P22L10E14.23,P22L14E14.23,P28L10E12.56,P28L14E12.56,P22L10E12.56 and P22L14E12.56.Final weight,weight gain,specific growth rates(SGR)and feed conversion ratio(FCR)were not significantly affected by dietary protein or dietary lipid or dietary digestible energy(P0.05),but were significantly affected by a dietary protein×lipid interaction(P0.05),and extremely significantly affected by a dietary protein×lipid×digestible energy interaction(P0.01).With the protein/energy ratio increasing,it took an increasing trend to final weight,weight gain and SGR(P0.05),except that fish fed diet P28L10E12.56.The digestibility of dietary protein,lipid,energy and dry matter is increasing when dietary digestible energy decreased(P0.05)and dietary lipid increased(P0.05).With the dietary protein decreasing,it took a decreasing trend to the digestibility of dietary protein,energy and dry matter(P0.05).The digestibility of dietary protein,lipid,energy and dry matter is increasing by dietary lipid levels(P0.05).Nitrogen retention was significantly increased as dietary protein levels decreased(P0.05),lipid retention decreased significantly with dietary digestible energy and lipid levels decreasing(P0.05),protein efficiency ratio(PER)was significantly increased as dietary digestible energy decreased(P0.05).Carcass protein and lipid were not significantly affected by dietary digestible energy concentrations(P0.05);however,carcass lipid tended to improve(P=0.066)as dietary digestible energy levels increased.The results of this study indicated that the diet containing 28% protein with 14% lipid and 12.56 kJ/g digestible energy is optimal for growth of juvenile channel catfish(150 to 300 g weight).However,group P28L10E14.23 and P22L10E12.56 got second best weight,highest nutrient utilization and best body composition of juvenile channel catfish.It also indicates that lipid saved protein in diet of juvenile channel catfish.

Replacement of fish meal in juvenile channel catfish, Ictalurus punctatus, diets using a yeast-derived protein source: the effects on weight gain, food conversion ratio, body composition and survival of catfish challenged with Edwardsiella ictaluri

We examined the effects of a yeast-derived protein source (NuPro®) as a replacement for menhaden fish meal on weight gain, specific growth rate (SGR), food conversion ratio (FCR), whole-body composition and disease resistance in juvenile channel catfish (9.9 ± 0.2 g fish−1). NuPro® replaced fish meal at six levels (0, 25, 50, 75, 100 and 125 g kg−1 diet). Catfish were sampled for whole-body composition and then challenged with the bacterium Edwardsiella ictaluri. Growth performance was negatively affected (P < 0.01) when NuPro® was added at 125 g kg−1 diet. The amount of whole-body fat decreased (P < 0.05) when NuPro® was added at 75 g kg−1 or more of the diet. Regardless of the amount of NuPro® added, survival after challenge with E. ictaluri was similar among treatments. Results indicate that up to 100 g kg−1 of NuPro® can be added without negatively affecting growth performance. The yeast-derived protein source used in this study is a sustainable protein alternative that could be used as a partial replacement for fish meal in juvenile channel catfish diets.

Use of Corn Gluten Feed and Cottonseed Meal to Replace Soybean Meal and Corn in Diets for Pond‐Raised Channel Catfish

AbstractThe prices of soybean meal and corn—the two most commonly used, traditional feed ingredients in channel catfish diets—have increased dramatically in recent years. Using less‐expensive alternative feed ingredients to partially replace soybean meal and corn would reduce feed cost. The present study evaluated the use of corn gluten feed and cottonseed meal, two promising alternative feedstuffs, as replacements for soybean meal and corn in diets for pond‐raised channel catfish Ictalurus punctatus. Five isonitrogenous (28% crude protein) diets that used corn gluten feed and cottonseed meal (approximately 1:1 ratio) to replace 0, 25, 50, 75, or 100% of the soybean meal in the control diet were evaluated. The level of corn in the diet decreased as those of corn gluten feed and cottonseed meal increased. Stocker‐size channel catfish (mean initial weight = 0.175 kg/fish) were stocked into twenty 0.05‐ha earthen ponds at a rate of 14,830 fish/ha. Fish were fed once daily to apparent satiation over a growing season. Net yield, carcass and fillet yield, and fillet protein and fat levels decreased and the feed conversion ratio increased linearly as soybean meal replacement levels increased. These results demonstrate that a maximum of 50% of the soybean meal in channel catfish diets may be replaced (soybean meal was reduced from 51.4% to 25.7%) by a combination of corn gluten feed and cottonseed meal (up to 20% of each in the diet) without markedly affecting the physical quality of feed pellets, fish growth, processed yield, and body composition. The poor performance of diets containing high levels of corn gluten feed and cottonseed meal are probably a result of high fiber, low digestible energy, or both.Received June 1, 2010; accepted October 1, 2010