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Fingerling Channel Catfish (fingerling + channel_catfish)
Selected AbstractsEffect of Dietary Protein Concentration and Stocking Density on Production Characteristics of Pond-Raised Channel Catfish Ictalurus punctatusJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2 2003Menghe H. Li Diets containing 28% and 32% crude protein were compared for pond-raised channel catfish Ictalurus punctatus stocked at densities of 14,820, 29,640, or 44,460 fish/ha. Fingerling channel catfish with average initial weight of 48.5 g/fish were stocked into 30 0.04-ha ponds. Five ponds were randomly allotted for each dietary protein ± stocking density combination. Fish were fed once daily to satiation for two growing seasons. There were no interactions between dietary protein concentration and stocking density for any variables. Dietary protein concentrations (28% or 32%) did not affect net production, feed consumption and weight gain per fish, feed conversion ratio, survival, processing yields, fillet moisture, protein and ash concentrations, or pond water ammonia and nitrite concentrations. Fish fed the 32% protein diet had slightly but significantly lower levels of visceral and fillet fat than fish fed the 28% protein diet. As stocking density increased, net production increased, while weight gain of individual fish, feed efficiency, and survival decreased. Stocking densities did not affect processing yield and fillet composition of the fish. Although highly variable among different ponds and weekly measurements, ponds stocked at the highest density exhibited higher average levels of total ammonia-nitrogen (TAN) and nitrite-nitrogen (NO2 -N) than ponds stocked at lower densities. However, stocking density had no significant effect on un-ionized ammonia-nitrogen (NH3 -N) concentrations, calculated based on water temperature, pH, and TAN. By comparing to the reported critical concentration, a threshold below which is considered not harmful to the fish, these potentially toxic nitrogenous compounds in the pond water were generally in the range acceptable for channel catfish. It appears that a 28% protein diet can provide equivalent net production, feed efficiency, and processing yields as a 32% protein diet for channel catfish raised in ponds from advanced fingerlings to marketable size at densities varying from 14,820 to 44,460 fish/ha under single-batch cropping systems. Optimum dietary protein concentration for pond-raised channel catfish does not appear to be affected by stocking density. [source] Evaluation of Various Concentrations of Dietary Protein and Animal Protein for Pond-Raised Channel Catfish Ictalurus punctatus Fed to Satiation or at a Restricted RateJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2000Edwin H. Robinson A factorial experiment was conducted to evaluate effect of dietary protein (28% or 32%), animal protein (0, 3, or 6%), and feeding rate (satiation or >90 kg/ha per d) on production characteristics, processing yield, and body composition of pond-raised channel catfish Ictalurus punctatus. Fingerling channel catfish (average weight: 55 g/fish) were stocked into 60, 0.04-ha ponds at a rate of 18,530 fish/ha. Five ponds were used for each dietary treatment. Fish were fed once daily to satiation or no more than 90 kg/ha per d for 147 d. Fish fed at a rate of >90 kg/ha per d consumed about 85% of the amount of feed consumed by fish fed to satiation. Dietary protein did not affect the total amount of feed fed, amount of feed consumed per fish, weight gain, feed conversion efficiency, or fillet protein. Animal protein had no effect on the total amount of feed fed, amount of feed consumed per fish, weight gain, or fillet protein and ash. Fish fed a diet containing 6% animal protein converted feed more efficiently than fish fed diets containing 0% and 3% animal protein. Fish fed to satiation daily consumed more feed, gained more weight, converted the feed less efficiently, and had a higher carcass yield, a higher level of visceral fat as compared to fish fed at a rate of >90 kg/ha per d. Feeding rate had no effect on fillet protein. Results from this study indicated that both a 28% and a 32% protein diet with or without animal protein provided the same growth rate of channel catfish raised in ponds from fingerlings to marketable size if feed is not restricted below a maximum rate of 90 kg/ha per d. Even though there were some interactions among the three factors evaluated, dietary protein levels of 28% to 32% and animal protein levels of 0% to 6% do not appear to markedly affect carcass yield and fillet proximate composition of pond-raised channel catfish. [source] Histologic changes in channel catfish, Ictalurus punctatus Rafinesque, fed diets containing graded levels of gossypol,acetic acidAQUACULTURE NUTRITION, Issue 4 2010J.J. EVANS Abstract A study was performed to evaluate the histologic changes among fingerling channel catfish, Ictalurus punctatus Rafinesque, fed purified diets containing gossypol from gossypol,acetic acid. The catfish were maintained on diets with 0, 300, 600, 900, 1200 or 1500 mg gossypol kg,1 diet for 12 weeks, and histologic samples from the stomach, proximal and distal intestines, pancreas, liver, and spleen were obtained from fish in all groups. Stomach sections exhibited significant gastric gland necrosis in fish fed 600 mg gossypol kg,1 diet or higher. Non-existent-to-mild enterocyte vacuolization loss, inflammatory cell infiltration, and hyperplastic lamina propria were noted in the intestinal sections from gossypol-fed fish, but no significant differences in severity scores were noted. The pancreas from fish fed doses of gossypol above 600 mg gossypol kg,1 diet exhibited significant mild-to-severe necrosis, and livers from fish fed 900 and 1500 mg gossypol kg,1 diet exhibited significantly higher pigment deposition. No other significant histologic differences were observed in the fish fed diets containing gossypol,acetic acid. The data in this study indicates that at least 600,900 mg gossypol kg,1 purified diet can cause statistically significant histologic changes in fingerling channel catfish, suggesting that gossypol should remain at concentrations below 600 mg gossypol kg,1 diet. [source] Chironomid abundance and consumption by juvenile channel catfish in plastic-lined and earthen culture pondsAQUACULTURE RESEARCH, Issue 9 2010Bonnie L Mulligan Abstract In 2004, research was conducted to compare chironomid larvae populations and their use by channel catfish (Ictalurus punctatus) fingerlings in two different culture systems. Over a 4-month culture period, chironomid larvae densities in plastic-lined ponds were significantly less than those in earthen ponds. The consumption of chironomid larvae by channel catfish fingerlings was related to chironomid abundance in earthen ponds. The significance of these findings is the possible relationship among pond type, initial consumption of commercial diets and subsequent survival rates of fingerling channel catfish. [source] | ||||||||||