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This study was conducted to investigate the effects of selenium nanoparticle (Se-NP) supplementation on the growth performance, carcass composition, antioxidant status, hepatic enzyme activities, and immunity of Cirrhinus mrigala. For this purpose, fish with an average initial weight of 7.44 ± 0.04 g were fed five experimental diets containing 0 (control), 0.25, 0.5, 1, and 2 mg kg-1 Se-NPs diets for 90 days. The analysed selenium (Se) contents of the diets were 0.35, 0.64, 0.92, 1.43, and 2.39 mg kg-1. Twenty five fish were randomly distributed in each of 5 aquarium (36 × 23.7 × 24.3 inches) in triplicate. The results showed that supplementation with Se up to 0.92 mg/kg significantly increased (p<0.05) weight gain, weight gain% (WG%), and specific growth rate (SGR) by 34%, 33%, and 16%, respectively, compared to the control diet. Dietary Se concentrations up to 0.92 mg/kg significantly increased the crude protein and crude fat and reduced (p<0.05) the moisture content as compared to the control group. Fish fed 0.92 mg kg-1 Se had significantly lower malondialdehyde (MDA) contents and higher activities of catalase, superoxide dismutase, and glutathione peroxidase in liver and serum as compared to other experimental diets. Moreover, a significant increase (p<0.05) in the level of serum immunoglobulin and lysozyme (LYZ) activity was recorded in fish fed 0.92 mg/kg Se diet. Moreover, the highest (p<0.05) values of aspartate transaminase (AST) and alanine transaminase (ALT) were recorded in fish fed 2.39 mg/kg Se level. However, serum alkaline phosphatase (ALP) activity remained unaffected by dietary treatment. Broken-line regression analysis indicated that 0.83 mg/kg Se is required for the optimum growth performance of C. mrigala. [ABSTRACT FROM AUTHOR]

The replacement of fishmeal (FM) with economical and nutritious FM alternatives including plant- and animal-based protein ingredients has become a global research priority. However, the presence of several anti-nutritional factors (ANFs) in these alternatives may impair nutrient utilization in fish. The supplementation of exogenous protease as feed additives could be an effective approach to improve the nutrient digestibility of these alternative proteins. Proteases are protein-digesting enzymes that catalyze the hydrolysis of complex protein macromolecules into simpler amino acids. Exogenous protease supplementation stimulates the activities of endogenous proteolytic enzymes for better nutrient digestion and absorption in fish. This review article summarizes the optimum protease supplementation levels in various fish species and its beneficial effects on growth performance, nutrient digestibility, intestinal morphology, digestive enzyme activities, whole-body composition, physiochemical parameters, immunity, and gene expression of fish. Moreover, the interactive effects of exogenous protease with organic acids and probiotics are also discussed. Overall, the supplementation of exogenous protease in fish feed is a viable solution for poor nutrient utilization of FM alternatives. Important gaps, however, exist in the current knowledge, particularly with regard to the effect of protease supplementation in animal-based proteins as most of the studies have focused on the effect of protease supplementation on plant-based proteins as FM alternatives. Moreover, additional studies focused on the effect of protease supplementation on the digestive enzyme activities, immunity, gut microbes and antioxidant parameters of fish will provide the basis for a better understanding of the mode of action of protease. The scarce knowledge in these areas limits the scope of protease supplementation as a feed additive in the aquaculture sector. [ABSTRACT FROM AUTHOR]

An experiment of 90-days was performed to investigate the effects of dietary calcium (Ca), phosphorus (P) and their interaction on growth, whole-body composition, nutrient digestibility and mineralization of silver carp, Hypophthalmichthys molitrix (average initial weight 13.7 ± 0.05 g). Nine isonitrogenous, isocaloric and isolipidic diets with three Ca levels (0, 1 and 2%) combined with three P levels (0, 1 and 2% P) were prepared. Results showed that silver carp fed the diet supplemented with 1% Ca and 1% P level yielded the similar (p > 0.05) growth performance as was recorded for that fed diet containing 2% Ca and 2% P. No significant difference in survival rate was recorded except for the diet containing 1% Ca with 2% P supplement. The feed intake (FI) of juvenile remained unaffected (p > 0.05) by mineral supplementation. Whole body protein content increased (p < 0.05) slightly with Ca and P supplementation. However, moisture, fat and ash contents remained unaffected (p > 0.05). Dietary Ca and P supplementation improved (p < 0.05) the protein and fat digestibility in silver carp. Ca and P contents showed significant increase (p < 0.05) with increasing Ca and P levels in the whole body, bones and scales, achieving the highest (p < 0.05) values at 2% Ca supplemented with 2% P. Whereas, Mg and Zn contents decreased (p < 0.05) with increasing Ca and P supplementation. Fish fed the diet containing 2% Ca level without P supplement had higher (p < 0.05) Ca/P ratio in whole body and bones. However, it decreased (p < 0.05) at 2% Ca level in scales. Further, increase in P supplementation significantly reduced (p < 0.05) Ca/P ratio regardless of Ca level. Conclusively, supplementation of 1% Ca in the presence of 1% P (1:1 ratio) is required for optimum performance of silver carp. [ABSTRACT FROM AUTHOR]

An 8-weeks feeding experiment was performed to study the requirement of vitamin E for rohu fingerlings. Six practical diets were fed to fingerlings including one control diet (E0) and five test diets (E25, E50, E75, E100 and E125) supplemented with graded vitamin E levels including 0, 25, 50, 75, 100 and 125 mg/kg. After the completion of trial, fish growth, vitamin E, antioxidant enzymes activities and fatty acids profile was determined. From the results it was concluded that the graded supplemental vitamin E levels improve the utilization of feed and fish growth. The antioxidant enzymes activities also showed significant results by increasing vitamin E level in the diet. However, an inverse relation was recorded between the contents of liver thiobarbituric acid reactive substances (TBARS) and vitamin E level in the diet. Moreover, analysis of fatty acids profile showed decrease in saturated and monounsaturated fatty acids (MUFAs). While, polyunsaturated fatty acids (PUFAs) were increased in all vitamin E supplemented diets compared to control group. Furthermore, vitamin E level of 80.62 mg/kg was found optimum for maximum growth performance in L. rohita fingerlings, beyond which no increase in growth was observed. [ABSTRACT FROM AUTHOR]

The dietary effect of vitamin E supplementation on fingerlings of Labeo rohita during refrigerated storage was investigated. Six graded levels of vitamin E, between 0-125 mg/kg vitamin E, were fed to fish. After 60-day feeding trial, fish were sacrificed, fillets were stored in refrigerator at -20°C and analyzed on 0, 15 and 30th day of storage. Upon refrigeration the vitamin E fed fish showed reduced level of Thiobarbituric acid reactive substances (TBARS) at all storage days. The enzyme activities were improved by elevating the levels of vitamin E in diet as well as by storage period (P < 0.05) for all treatments. Fatty acid profile indicated that n-3, n-6 fatty acids and the ratios of ARA/EPA and n-3/n-6 were increased by increasing vitamin E supplementation and decreased with an increase in the storage period. Conclusively, the dietary vitamin E reduced lipid peroxidation and improved the fillet quality of stored fish. [ABSTRACT FROM AUTHOR]

This study was planned to determine intestinal digestive enzymes activity and bone mineralization of Ctenopharyngodon idella. Four type food were prepared by using formic acid (%) and vitamin D3 (IU/Kg) in experiment viz, FD1, FD2, FD3 and FD4, respectively. Fish fed with formic acid showed considerable increase in calcium, magnesium potassium, however vitamin D3considerably increase iron and manganese contents (µg/g) in the bones of C. idella. Amylase and protease activity was maximum in fish intestine fed with formic acid followed by fornic acid × vitamin D3, vitamin D3 = control diet. Activity of lipase enzyme was reduced by formic acid supplementation as well as vitamin D3. The observed formic acid and vitamin D3 (interactions) were synergistically bone mineralization of phosphorus, sodium, copper and also showed positive result for the activity of amylase, protease and lipase. Finally, formic acid and vitamin D3improves bone mineralization and digestive enzymes activity in the C. idella. [ABSTRACT FROM AUTHOR]

The present experimental study was conducted to determine the effects of xylanase supplementation on growth performance, nutrient digestibility and digestive enzyme activities of mori, Cirrhinus mrigala. Mori with an initial body weight of 8.34 ± 0.23 g were fed seven experimental diets: a diet with high fish meal content (positive control, PC), a diet with high plant content (negative control, NC), and five other diets with increasing levels of xylanase (680, 1273, 1882, 2486 and 3091 U/kg). Each diet was fed to triplicate groups of 15 fish each for 60 days. After the trial termination, supplementation of xylanase significantly improved final weight (FW), weight gain (WG) and specific growth rate (SGR) compared to NC diet. The best feed conversion ratio (FCR) was observed at 1882 U/kg of xylanase supplementation level which was non-significant (P > 0.05) to PC diet (high fish meal content). Whole body proximate composition and apparent digestibility coefficient (ADC%) for dry matter (DM), crude protein (CP), crude fat (CF), crude ash (CA) and gross energy (GE) were significantly affected by xylanase supplementation. Activities of hepatopancreatic and intestinal amylase, protease and lipase showed an increasing trend with the increase in xylanase supplementation level, peaking at 1882 U/kg of xylanase (non-significant (P > 0.05) to PC diet) and declining thereafter (2486 U/kg-3091 U/kg). Quadratic regression analysis showed that 1948 U/kg of xylanase was the optimum value for supplementation of xylanase in plant-based diet. In conclusion, exogenous xylanase supplementation improved the growth performance, nutrient digestibility and digestive enzyme activities in juvenile mori fed plant-based diet. • First article to focus on xylanase supplementation on juvenile mori (Cirrhinus mrigala). • Exogenous xylanase improves growth performance, nutrient digestibility and digestive enzyme activities. • Quadratic regression analysis for weight gain% (WG%) showed that 1886 U/kg of xylanase was the optimum value for supplementation of xylanase in plant meal based diet. [ABSTRACT FROM AUTHOR]