Effects of dietary Biogen and sodium butyrate on hematological parameters,immune response,and histological characteristics of Nile tilapia (<Emphasis Type="Italic">Oreochromis niloticus</Emphasis>) fingerlings

The present study was carried out to evaluate the use of Biogen and sodium butyrate (SB) as feed additives in the diet of Nile tilapia (Oreochromis niloticus) fingerlings, in two parallel experiments. Biogen was incorporated in isonitrogenous (35% crude protein) and isocaloric (19 MJ kg^?1) diets at four levels (0.0 (control), 0.5, 1.0, and 2.0%), while SB was included at five levels (0.0 (control), 0.5, 1.0, 2.0, or 3.0%). The diets were fed to fingerling Nile tilapia (10.5 ± 0.5 g) at a daily rate of 4% of their body weight, three times a day, for 60 days. Except the lymphocytes and monocyte numbers in fish fed SB, hematological parameters, including red blood cell (RBC) hematocrit (Ht), hemoglobin (Hb), and white blood cells (WBC) were not significantly (P > 0.05) affected by dietary Biogen and SB. The lymphocytes number in Nile tilapia fed on SB increased with increasing SB up to 2% level, and decreased afterwards. Monocyte numbers showed irregular patterns. The activities of serum enzymes alanine aminotransferase (ALT) and aspartate aminotransferase (AST) of fish fed diets containing Biogen or SB were not significantly affected by dietary treatments (P > 0.05). No structural differences of tilapia liver were detected between all Biogen treatments and sodium butyrate concentrations up to 1% with control. At concentrations of 2 and 3% sodium butyrate, liver steatosis increased leading to shrinked acentric nuclei. At a concentration of 2% Biogen, some glomerulus cells had fading cytoplasm. Concerning fish fed SB diets, the structure of kidney was the same as in control except at concentration of 3% SB, where the septum between cells disappeared. No changes in gill structure were noticed at all concentrations of Biogen and SB.     

Effect of thiamine injection on growth performance,hematology and germinal vesicle migration in sterlet sturgeon Acipenser ruthenus L.

The present study aimed to investigate the effect of thiamine on growth, hematological, egg thiamine content and oocyte nucleus migration indices in sterlet sturgeon (Acipenser ruthenus). A total of 45 female fish (698.6 ± 8.9 g) were distributed in nine fiberglass tanks with three treatments (each in three replicates). Experimental fish were fed once a day with practical diet supplemented with 1 g kg^?1 amprolium hydrochloride (as the antithiamine) for 5 months before spawning. Thiamine hydrochloride was injected to fish with one of three doses at 0, 5 and 50 mg kg^?1 body weight (BW) at three different stages. At the end of each month, fish were weighed and growth parameters such as weight gain, specific growth rate, feed efficiency and final weight were determined. At the end of the 5-month period, hematological parameters and egg thiamine content were measured. The results showed no significant differences in terms of growth performance. Hemoglobin, number of red blood cells and white blood cells were not significantly different among the treatments, but hematocrit was significantly higher in fish injected with 5 mg kg^?1 BW thiamine. The mean corpuscular volume and mean corpuscular hemoglobin were not significantly different, but lower value of mean corpuscular hemoglobin concentration was observed in fish injected with 5 mg thiamine. Percentage of lymphocytes, neutrophils, eosinophils and monocytes were not significantly different among treatments. The results of the germinal vesicle migration index at different stages showed no significant differences in different groups. Results showed that free thiamine, thiamine pyrophosphate and total thiamine in eggs significantly increased at 50 mg kg^?1 injection dose compared with the control, but no significant different was found in thiamine monophosphate. The results revealed that thiamine injection to sterlet broodstocks has positive accumulation in egg thiamine content and some hematological parameters but have no effect on growth and ovarian maturation. We conclude that thiamine can affect some physiological features of broodstock, which needs to be specified in further studies.     

Yield and Economic Efficiency of Green Water in Combination with Supplemental Feeds for Artemia Production in Vietnamese Salt Ponds

We evaluated the combined effects of different green water sources and feed supplements on Artemia biomass production and economic efficiency. A two-factor experiment was set up with two green water types produced from the ratios of nitrogen and phosphorus (N:P = 5 and N:P = 10) in combination with two types of supplemental feed (rice bran or pig manure). After 12 weeks of culture, total Artemia biomass yield with the N:P = 5 treatment (2.29 ton ha^?1 crop^?1) was 14% higher than that with the N:P = 10 treatment (1.97 ton ha^?1 crop^?1), although this difference was not significant (P > 0.05). There was no significant interaction between green water and supplemental feeding treatments for the final yield of Artemia biomass. Comparative cost-benefit analysis showed that the treatment of N:P = 5 combined with pig manure attained a significantly higher net profit and cost/benefit ratio than the other treatments.     

Effects of supplementation of pineapple waste extract in diet of Nile tilapia (Oreochromis niloticus) on growth,feed utilization,and nitrogen excretion

An eight-week feeding trial was conducted to evaluate the supplementation of pineapple waste extract (PWE) at levels of 0%, 1%, 2%, and 3% on growth performance of Nile tilapia (8.76 ± 0.17 g) for 8 weeks. PWE supplementation improved pepsin digestibility significantly but not protein digestibility. Thus, fish fed PWE showed better growth than those fed the control feed. The fish fed the feed supplemented with 1% PWE resulted in the optimum protein digestibility, growth, and feed utilization (P < 0.05). No significant differences among dietary treatments were found for free ammonia and total nitrogen excretion (P > 0.05).     

Effects of probiotic Pediococcus acidilactici on growth performance,survival rate,and stress resistance of Persian sturgeon (Acipenser persicus)

This study was conducted to examine the effect of Artemia urmiana nauplii enriched with Pediococcus acidilactici on growth performances, survival rate, and stress resistance of Persian sturgeon (Acipenser persicus). Artemia nauplii were enriched with P. acidilactici at concentration of 10¹⁰ CFU/ml for 3 h (T3), 6 h (T6), 9 h (T9), and one nonenriched nauplii treatment (control). Since nauplii enriched for 9 h had the most significant CFU/g, fish were fed with T9 for 11 days and compared with the control. To evaluate the effect of probiotic on fish resistance, Persian sturgeon larvae were subjected to osmotic shocks of 15, 25, or 35 ppt; four pH treatments, pH 5, pH 6, pH 8 or pH = 9; and air for 5, 10, 15, or 20 s on the 11th day. There were no significant differences in final weight, weight gain, CF, SGR, and FCR between T9 and control (P > 0.05). However, the survival rate of larvae fed nauplii enriched for 9 h increased significantly in comparison with the control group (P < 0.05). In addition, significant higher resistance to all stress challenges was observed in the T9 group.     

Effect of microencapsulated thyme essential oil on white spot virus-infected <Emphasis Type="Italic">Litopenaeus vannamei</Emphasis>

The present work was performed to investigate if feeding Litopenaeus vannamei with microencapsulated thyme essential oil (TEM, 1.05 g thyme essential oil per 100-g powder) adsorbed on commercial pellet feed was able to protect shrimps against white spot syndrome virus (WSSV) disease. Five treatments were tested: uninfected shrimp fed with commercial pelleted feed (T_C, negative control), WSSV-infected shrimp fed with commercial pelleted feed (T₁, positive control), WSSV-infected shrimp fed with commercial pelleted feed with 0.1% TEM (T₂), WSSV-infected shrimp fed with commercial pelleted feed with 0.5% TEM (T₃), and WSSV-infected shrimp fed with commercial pelleted feed with 1% TEM (T₄). At 72 h post infection, phenoloxidase activity of shrimps treated with 1% TEM did not show significant differences with T_C values but it was significantly higher than that of the other treatments (T₁, T₂, and T₃). Moreover, shrimps treated with T₄ presented absence of clinical signs of WSSV infection and their survival rate was significantly higher than that of T₁, T₂, and T₃ treatments. Therefore, 1% TEM seemed to protect shrimps against WSSV symptoms. Using microencapsulated thyme essential oil may help to fight against WSSV in shrimp farms.     

Quality Changes in Chum Salmon (Oncorhynchus keta) Caviar (ikura) Affected by Thermal Pasteurization,Storage Time,and Packaging Material

Changes in quality parameters including pH, water activity, texture, and lipid oxidation were studied in pasteurized chum salmon (Oncorhynchus keta) ikura samples packaged using two films with different oxygen transmission rates (OTR) (40 and 62 cm³·m^?2·day^?1; F-40 and F-62), during 60 days storage at 4°C. No significant differences in pH and water activity (a_w) were observed between ikura packaged using two different films with different OTR (P > 0.05). However, compared to the first day of study, water activity decreased significantly in ikura (P < 0.05). Ikura thiobarbituric reactive substance (TBARS) in the pouches significantly increased during the storage at 4°C (P < 0.05). Both pouches showed similar trends in TBARS until day 29, while after day 29, ikura packaged in F-62 (OTR = 62 cm³·m^?2·day^?1) showed a significant increase in TBARS compared to F-40 with less OTR (P < 0.05). The texture of ikura became softer compared to the first day; however, no significant difference was observed between the ikura samples in two pouches (P < 0.05). The quality changes of ikura measured during storage indicate that packaging ikura in a lower OTR film would provide greater quality retention than one with higher OTR.     

Preclinical toxicity and safety evaluation of Althaea officinalis L. extract as naturopathic medicine in common carp (Cyprinus carpio L.): Hematological and biochemical study

ABSTRACT

This study was conducted to evaluate the effects of marshmallow extract (Althaea officinalis L.) administration on blood cells and biochemical parameters of carp liver. A total of 150 carps (Cyprinus carpio, initial body mass of 37.7 ± 4.4 g) were fed diets containing 0.0 (control diet), 2.5, 5, and 10 g marshmallow extract for 60 days. On days 30 and 60 of the experiment blood samples were collected and hematological parameters and liver enzyme activities—aspartate aminotransferase (AST), alanine amino transferase (ALT), lactate dehydrogenase (LDH), and alkaline phosphatase (ALP)—were measured. No significant difference was found (p > .05) in red blood cells (RBC); hemoglobin concentration (Hb); hematocrit (Htc); mean corpuscular volume (MCV); mean corpuscular hemoglobin concentration (MCH); or the percentage of neutrophils, basophils, and eosinophils in fish fed with different concentrations of marshmallow extract on days 30 and 60. However, the white blood cell (WBC) count was increased significantly in the fish fed for 60 days with feed supplemented with 5 g marshmallow extract (p < .05). The MCHC was increased signi?cantly in ?sh fed with diets supplemented with 2.5 g marshmallow extract for 60 days (p < .05). Administration of marshmallow extract (5 g) significantly increased (p < 0.05) lymphocytes on days 30 and 60. However, dietary intake of 10 g marshmallow extract had significantly decreased the monocyte percentage after 60 days. A significant increase was observed in AST, ALT, ALP, and LDH levels in livers of fish fed with extract 10 g, which may be attributed to cytotoxicity. However, marshmallow extract 2.5 and 5 g did not have adverse effects on liver enzymes. These results indicate that preclinical dietary supplementations of 2.5 and 5 g marshmallow extract per kg diet have no side effects on common carp.     

Effects of a probiotic, protexin, on the growth performance and hematological parameters in the Oscar (Astronotus ocellatus) fingerlings

This study examined the effects of a probiotic, protexin, on the growth performance and hematological parameters in an ornamental fish, the Oscar Astronotus ocellatus fingerlings. A completely randomized experimental design was applied with three experimental diets each with three replicates. A commercial food, BioMar, was supplemented with protexin at levels of 0.15, 0.5, and 1.0 g kg(-1) dry food and fed three times a day for 60 days. The control diet was prepared with no protexin supplementation. The experimental fish were biometried every 15 days to compare their growth rates at each treatment. For hematological assays, blood samples were prepared every 30 days to measure such parameters as red and white blood cells, hemoglobin, hematocrit, and percentages of lymphocytes, monocytes, neutrophiles, basophiles, and eosinophiles. Based on the results, the fingerlings fed a 0.15 g kg(-1) supplemented food were significantly different from the fish in the other treatments and in the control, with the highest mean of both final weight (35.07 ± 1.19) and body weight gain (30.17 ± 1.08). Significant differences in both hemoglobin concentration and mean red and white blood cells were found between the experimental groups and the control within 2 months. The highest hemoglobin concentration and also red and white blood cells was observed in the fish-fed 0.15 dietary protexin in both months. The results of this study show that the probiotic, protexin, at a level of 0.15 g kg(-1) dry food could have measurable effects on the growth and hematological parameters in the Oscar A. ocellatus fingerlings.     

Incorporating Roasted Coffee Bean into Nile Tilapia Diets Does Not Improve Growth Performance

This study was conducted to use ground roasted coffee bean (GRC; Coffee arabia) as a feed supplement in diets for Nile tilapia, Oreochromis niloticus. Fish (1.9 ± 0.03 g) were fed diets containing 0.0, 0.5, 1.0, 2.0, or 5.0 g GRC/kg in triplicate for 10 weeks. Final fish weight, weight gain, and specific growth rate were not significantly (P < 0.05) affected by GRC incorporation up to 1.0 g/kg, after which growth declined. Fish fed diets containing 2.0 and 5.0 g GRC/kg consumed less than the other treatments, giving the highest FCR (1.4 and 1.5, respectively). No significant differences were observed in fat efficiency ratio, protein efficiency ratio, and energy utilization for the 0.0–1.0 GRC/kg diets; lowest values of these parameters were obtained with the 2.0 and 5.0 g GRC/kg diets. Supplementation of GRC significantly reduced fish whole-body protein content and increased lipid and ash.     

Preliminary evaluation of purified lignin and hemicellulose as prebiotics candidates for Atlantic Salmon,Salmo salar L.

A study was conducted to investigate the potential of purified lignin and hemicellulose as prebiotics in diets for Atlantic salmon, Salmo salar L., postsmolt in seawater (30 ppt) at 14.9 ± 1.2°C. Triplicate groups of fish (initial individual body mass of 101.6 ± 1.2 g) were fed either the fishmeal-dense (32% of fishmeal) control diet (A) or one of the nine diets (15% fishmeal) supplemented with lignin:hemicellulose ratios (% diet:% diet) of 0.05:0 (B), 0.25:0 (C), 0.50:0 (D), 1.00:0 (E), 0:0.05 (F), 0:0.25 (G), 0:0.50 (H), 0.05:0.25 (I), and 0.25:0.50 (J) for 12 weeks in a complete randomized experimental design. At the end of the experiment, the thermal-unit growth coefficient (TGC) was significantly lower in salmon fed diets with 0.50% and 1.00% purified lignin than those fed the control diet, while there was no significant difference between the other treatments and the control diet (P < 0.05). The feed efficiency (FE) was significantly lower in salmon fed diets with 0.50% and 1.00% purified lignin and 0.05% hemicellulose than those fed the control diet, while there was no significant difference between the other treatments and the control diet (P < 0.05). The hepatosomatic index (HSI), intestinal villus length, and apparent digestibility coefficient (ADC) of nutrients in diets were similar (P > 0.05) among all the diets. This study demonstrated that inclusions of up to 0.25% of dietary purified lignin alone, and 0.25%–0.50% of dietary hemicellulose alone or in combination with dietary lignin can be considered as candidate prebiotics in Atlantic salmon nutrition.     

Some physiological studies on the effect of onion and garlic juices on the fish, Clarias lazera

Fish, Clarias Lazera were orally administered onion (Allium cepa) or garlic (Allium sativum) juices. Contents of glucose, free amino acids, total lipids, triglycerides, cholesterol, albumin, total protein, urea, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in serum as well as glycogen, free amino acids, total lipids, triglycerides and cholesterol contents in liver, white and red muscle were determined 5 h and 24 h after a single dose or after repeated doses (1 dose every 24 h for 5 days). Both onion and garlic treatments caused a temporary hypoglycemia as well as liver glycogen muscle depletion accompanied with a significant elevation in white muscle glycogen suggesting that dietary onion or garlic may enhance the process of glycogenesis in white muscle. Onion feeding caused hypolipidemia accompanied with significant decreases in liver content of total lipids in response to the repeated doses for 5 days and a severe rise in the lipid content of red muscle at all periods. Such results suggest that dietary onion may enhance the process of lipogenesis in red muscle of Clarias lazera. Probably, the main precursor of such lipogenesis in the red muscle was the serum fatty acids. Moreover, dietary onion led to hypocholesterolemia accompanied with a significant rise in cholesterol level of both liver and red muscle. On the other hand, dietary garlic significantly decreased serum free amino acids after 5 h and 5 days. Furthermore, significant elevations of liver free amino acids were dedected in the onion-treated fish group (24 h and 5 days) and in the garlic-treated fish group (5 h), probably due to oxidation of thiol components (sulfur attached to the proteins). This result was accompanied with either a marked increase in white muscle free amino acids at all periods of garlic fish group, or a noticeable drop in the onion group (repeated doses). Also, dietary onion and garlic treatment led to an elevation in hepatic ureagenesis in spite of the unchanged serum urea level. Significant decreases of both serum AST and ALT in garlic groups (all periods) and in onion groups (repeated doses) were observed. In liver, AST and ALT showed temporary rises after onion or garlic supplementation. In general, it could be concluded that both dietary onion and garlic have a transitory hypoglycemic action as well as a promoting effect on the process of glycogenesis in white muscle whereas dietary onion promotes lipogenesis in red muscle of fish. Also, dietary garlic may enhance the white muscle uptake of free amino acids which, in turn, may promote protein synthesis.     

Toxicological and hematological effect of <Emphasis Type="Italic">Terminalia arjuna</Emphasis> bark extract on a freshwater catfish, <Emphasis Type="Italic">Heteropneustes fossilis</Emphasis>

Increasing demand for eco-friendly botanical piscicides and pesticides as replacements for harmful synthetic chemicals has led to investigation of new sources of plant materials. Stem bark of Terminalia arjuna, which has been used as a popular folk medicine since ancient time, was examined for its piscicidal activity. This study aims to determine toxicity of ethanol extract of T. arjuna bark on fresh water stinging catfish (Heteropneustes fossilis), along with evaluation of changes in hematological parameters of the fishes exposed to a lethal concentration. The percent mortality of fishes varied significantly in response to concentrations of the extract and exposure times (between exposure time F = 36.57, p < 0.001; between concentrations F = 39.93, p < 0.001). The lethal concentrations (LC₅₀) of ethanol extract were found to be 12.7, 8.94, 5.63 and 4.71 mg/l for 24, 48, 72 and 96 h, respectively. During acute toxicity test, blood samples of treatment fishes showed significant decreases in the red blood cells count, hematocrit content, hemoglobin concentration, mean corpuscular hemoglobin concentration and plasma protein level when compared to those of the control group, while there were significant increases in the mean corpuscular volume, mean corpuscular hemoglobin, white blood cells count and plasma glucose concentration. These results suggest that T. arjuna bark extract could be considered as a potent piscicide due to its toxic effect on fish, particularly fish hematology.     

Could the growth of Litopenaeus vannamei be compensated by long-term cyclic feed deprivation and following refeeding?

ABSTRACT

The effects of long-term cyclic feed deprivation and refeeding on compensatory growth and body composition of Litopenaeus vannamei were assessed for five different feeding protocols (i.e., 0, 1, 2, 4, 7 days fasting/days feeding) during 15 study weeks. Shrimp in each tank were weighed to calculate growth parameters. The control group has shown the highest specific growth rate (SGR) and the highest final weight compared to the cycling-feeding groups during the first 8 weeks (P < 0.05). On the other hand, during the realimentation period (9–15 weeks), SGR of the cycling feeding groups and the control group are equivalent (P < 0.05). It has been concluded that long-term cycling starvation and feeding treatment lead to compensatory growth of L. vannamei. Final survival rates ranged between 64.4% and 79.9% in all the groups (P > 0.05).     

Evaluation of different concentrations of adult live Artemia (Artemia franciscana,Kellogs 1906) as natural exogenous feed on the water quality and production parameters of Litopenaeus vannamei (Boone 1931) pre-grown intensively

A 7-week experimental study was performed to evaluate the effect of five concentrations of adult live Artemia (0, 1, 2, 3 and 4 L⁻¹) as exogenous natural feed on the water quality and production parameters of juvenile (0.2 ± 0.01 g) shrimp (Litopenaeus vannamei) pre-grown intensively (125 organism m⁻²) under laboratory conditions (80 L plastic tanks). No significant differences were observed in the environmental variables among treatments. Total ammonium nitrogen, nitrates and phosphates recorded higher concentrations in all the treatments using artemia, as compared with the treatment without Artemia. In all the cases, the levels remained within or close to the ranges considered necessary for the farming of the species. The highest weight gain and biomass were obtained in the treatments with 3 and 4 Artemia L⁻¹. The best feed conversion ratio were recorded using 2 Artemia L⁻¹ and the highest with 0 Artemia L⁻¹. No differences in survival were detected among treatments. The greatest concentrations of nitrogenous metabolites achieved at the highest densities of Artemia were lower than the LC₅₀ for penaied shrimp and no negative effect was observed on the survival of the shrimp. These results clearly indicate that the use of adult live Artemia as exogenous natural feed significantly increased the production parameters of the Pacific white shrimp.     

Quantitative dietary isoleucine requirement of juvenile Pacific white shrimp,Litopenaeus vannamei (Boone) reared in low-salinity water

This study was designed to determine the isoleucine requirement of juvenile Pacific white shrimp Litopenaeus vannamei (Boone) in low-salinity water (0.50–0.70 g L^?1). Six diets were formulated to contain 410 g kg^?1 crude protein with fish meal, peanut meal and pre-coated crystalline amino acids with different concentration of l-isoleucine (9.35, 11.85, 14.35, 16.85, 19.35, and 21.85 g kg^?1 dry diet, defined as diet I1, diet I2, diet I3, diet I4, diet I5 and diet I6, respectively.). Each diet was randomly assigned to triplicate treatments of 30 shrimps (0.43 ± 0.005 g), and the feed trial lasted for 8 weeks. The results indicated that the weight gain significantly increased with increasing isoleucine concentration up to 14.35 g kg^?1 (diet I3), whereas it was reduced in the treatments exceeding 16.85 g kg^?1 isoleucine (diet I4) significantly (P < 0.05). Moreover, the highest body protein deposition and protein efficiency ratio, and the lowest feed conversion ratio, haemolymph aspartate aminotransferase and alanine aminotransferase activities were also found at treatment I3–I4 (P < 0.05). And the haemolymph urea nitrogen concentration of shrimps-fed diet I6 was particularly higher than those fed with diets I1–I5 (P < 0.05). The results of polynomial regression based on weight gain, feed efficiency and body protein deposition indicated that the optimal dietary isoleucine requirement for L. vannamei reared in low-salinity water was 15.95 g kg^?1 isoleucine of dry diet, correspondingly 38.81 g kg^?1 of dietary protein.     

Effects of dietary Lactobicillus plantarum on the growth,carcass quality,and immune response of African catfish (Clarias gariepinus) challenged with Salmonella typhi

An experiment was conducted to investigate the effects of Lactobacillus plantarum on the production of African catfish (Clarias gariepinus). Five experimental diets containing 0, 10³, 10⁵, 10⁷, and 10⁹ CFU of Lactobacillus plantarum g^?1 diet (T₁–T₅ treatments respectively) were fed to African catfish (Clarias gariepinus) (9.20 ± 0.1 g initial body mass), for 70 days. Results indicated significantly lower growth performance in the fish fed diet without probiotics and in those fed diet with the least probiotic level. Treatments with probiotics significantly improved the blood profile and carcass protein but significantly reduced the carcass fat (P < 0.05); these treatments also marginally improved the carcass minerals in comparison with the treatment without probiotic (P < 0.05). Challenging the fish fed the experimental diets with Salmonella typhi showed higher immunity of fish fed the probiotic diets than those fed the nonprobiotic diet. Duncan’s multiple range test showed that the best fish performance was observed with 10³ CFU g^?1 L. plantarum for very parameter measured. However, regression analyses showed the optimum level of the bacteria to be 10^4.13–10⁵ CFU g^?1     

The role of dietary L‐ascorbyl‐2‐polyphosphate on the growth and physiological functions of beluga,Huso huso (Linnaeus, 1758)

Effects of dietary ascorbic acid (AA) supplementation were carried out on growth performance and physiological indices in juvenile beluga Huso huso fed different levels of dietary L‐ascorbyl‐2‐polyphosphate as AA source consisting of 0 (control), 100, 200, 400, 800 and 1600 mg AA kg^?1 diet for 16 weeks. No significant differences were found in growth performances between treated groups except for condition factor. Using AA caused significant differences in haemoglobin, number of red blood cells, white blood cells, aspartate aminotranspherase and lactate dehydrogenase, while no significant difference was found in haematocrit, mean corpuscular haemoglobin concentration, differential white blood cells count and alkaline phosphatase activity at the end of the experiment. Lysozyme activity after 8 weeks was significantly affected by dietary treatments with the lowest value in fish fed control diet, but not at completion of 16‐week feeding trial. Liver AA concentration showed a significant increase in correlation with dietary AA increase. Air exposure stress test showed significant differences among the treatments in case of cortisol and glucose concentrations. Also between pre‐ and post stress, significant changes were observed in some of treatments. The lowest and highest levels of cortisol were 9.2 ± 3 (in 200 mg kg^?1) and 16.8 ± 5.1 ng mL^?1 (in control), 6 h post stress (P < 0.05) respectively. Also, the lowest and highest levels of glucose were measured in fish fed 200 and 800 mg AA kg^?1 respectively. The obtained results showed that most growth parameters were not affected by dietary AA, but some physiological and immunological parameters of this species were influenced by this vitamin. We suggest that under rearing conditions, AA should be added to the diet especially during early life stages for improving health status and resistance to stressors.     

Effects of dietary organic,inorganic, and nanoparticulate selenium sources on growth,hemato-immunological,and serum biochemical parameters of common carp (<Emphasis Type="Italic">Cyprinus carpio</Emphasis>)

An 8-week feeding trial was conducted to compare the effects of supplementing (0.7 mg kg^?1) different dietary selenium (Se) sources including organic [selenomethionine (SeMet)], inorganic [sodium selenite (Na₂SeO₃)], and nanoparticulate Se (nano-Se) on physiological responses of common carp, Cyprinus carpio juveniles (9.7?±?0.1 g). Basal diet without Se supplementation used as control. Fish fed nano-Se supplemented diet had the highest weight gain (97.2?±?10.8%) and feed efficiency ratio (42.4?±?0.8%). Intestinal villi height was significantly taller in fish fed nano-Se diet than in the control group in both foregut and midgut sections. Serum glutathione peroxidase and superoxide dismutase activities were significantly higher in nano-Se and SeMet groups than in control and sodium selenite groups. Fish fed Se-supplemented diets had greater red blood cell counts and hematocrit and hemoglobin values than the control group (P?<?0.05). Nano-Se and SeMet groups showed a significant increase in white blood cell counts, neutrophil percentage, and serum lysozyme activity than the other groups. Fish fed nano-Se diet had the highest serum hemolytic activity, total immunoglobulin, and total protein and albumin contents, as well as the lowest serum total cholesterol and low density lipoprotein levels (P?<?0.05). Overall, significant improvements in growth performance, feed utilization, intestinal morphology, and hemato-immunological and serum biochemical parameters of common carp juveniles suggest nano-Se as an efficient source for providing dietary Se in this species.     

Phosphorus utilization in juvenile Clarias gariepinus fed phytase-supplemented diets based on soya bean (oil-extracted) and full-fat (roasted): A comparison

The effect of microbial phytase on phosphorus utilization in juvenile Clarias gariepinus (initial fish body weight 11.55 ± 0.2 g) was tested on two different diets based on oil-extracted soya bean (Experiment 1) and roasted soya bean meal (Experiment 2) using a 5 × 5 experimental design for 84 days. The basal isonitrogenous and isocaloric diets for oil-extracted and roasted soya bean were formulated to replace fish meal at 25% (S1E), 50% (S2E), 75% (S3E), 100% (S4E); and 25% (S1), 50% (S2), 75% (S3), 100% (S4), respectively. Each treatment was replicated four times. Microbial phytase was supplemented in each replicate at 250 FTU/g (P1), 500 FTU/g (P2), 750 FTU/g (P3), and 1,000 FTU/g (P4). Basal controls, which included a fish meal-based diet (S0), were not supplemented with phytase (P0). The result in Experiment 1 showed that there was a significant increase in whole-body protein and reduction in fat with phytase compared to a diet without phytase (P < 0.05). Serum total protein declined significantly with phytase supplementation (P < 0.05). Serum phosphorus and glucose were higher with phytase supplementation compared to control (P < 0.05). Bone minerals declined significantly with increasing level of soya bean compared to fish meal diet (P < 0.05). In Experiment 2, serum phosphorus was improved with phytase compared to control with no phytase (P > 0.05). A significant reduction in whole-body protein and increase in fat was observed for fish fed phytase diets compared to diets with no phytase, regardless of soya bean level (P < 0.05); however, ash content was improved with phytase (250 FTU/g) compared to control (P < 0.05). Phytase supplementation improved bone phosphorus (250 FTU/g), calcium (250 FTU/g), magnesium (250–500 FTU/g), and zinc (250–1,000 FTU/g) compared to control (P < 0.05). In conclusion, the research has demonstrated that improved bone phosphorus (P) and growth could be achieved with the supplementation of dietary phytase.