Effect of dietary phytase and wheat bran on some growth performances and phosphorus absorption function of common carp (Cyprinus carpio) fry

In this study, the effect of dietary phytase and wheat bran on some growth performances and phosphorus absorption function of common carp fry for 60 days was assessed. A total number of 180 common carp fry (20±1 initial weight) was randomly distributed in six experimental groups including, control group without any additive (basal diet), T1 (basal diet+2000 IU/Kg phytase), T2 (basal diet+4000 IU/Kg phytase), T3 (basal diet+20 g/Kg wheat bran), T4 (basal diet+40 g/Kg wheat bran) and T5 (basal diet+2000 IU/Kg phytase+20 g/Kg wheat bran). The highest body weight (150.02±4.76 g), specific growth rate (0.65±0.19%), and condition factor (3.20±0.26%) was observed in T5 (p<0.05). However, the lowest FCR (2.53±0.70) was seen in T5 (p<0.05). Also, the highest phosphorus concentration in the fry bones (2.54±0.003 ppm) was recorded in T5 (p<0.05). Results showed that using of 2000 IU/Kg phytase and 20 g/Kg wheat bran in the diet can improve growth indices and phosphorus absorption rate of common carp fry

Nutritional value and heavy metal content of fishmeal from the Southwest Caspian Sea

This study aimed to evaluate some nutritional values and heavy metal contents of fishmeal produced by the commercial factories in Guilan Province, the Southwest Caspian Sea. The fishmeal samples were randomly collected from five factories producing fishmeal by Kilka (Clupeonella spp.) (units 1-4) and tuna canning offal (unit 5) as the raw materials. Proximate fish composition, amino acid contents and four heavy metal concentrations including chromium (Cr), cadmium (Cd), lead (Pb), and mercury (Hg) were measured in the fishmeal specimens. Crude protein contents were found to be in the range of 53.61-68.82% and the lowest value belonged to the unit 5. Also, the highest level of fat and ash contents were 22.49% and 18.05%, respectively (p < 0.05). The lowest essential: nonessential amino acid ratio was 0.71 in unit 5. Fishmeal specimens from unit 5 showed the highest metal concentrations with the following descending order: Cr > Cd > Pb > Hg. Results indicated that the heavy metal concentrations in the fishmeal are dependent on the source of raw materials. The heavy metal concentrations in the examined fishmeal did not exceed the permissible limits proposed by National Research Council (NRC) for animal feedstuff requirements

Impacts of extremely low-frequency electromagnetic fields (50-Hz) on growth performance and survival rate of common carp, Cyprinus carpio fingerlings

All organisms are probably exposed to different types of electromagnetic fields (EMFs). This study is an attempt to evaluate the effect of extremely low-frequency EMFs (50 Hz) on some growth parameters and survival rate of common carp fingerling. The fish (n = 120, averaged 16.76 ± 0.88 g in initial weight) was exposed to ELF-EMF at four intensities of 0.1, 0.5, 1 and 2 mT only once for 2 h and then reared for 60 days. The obtained results revealed that all growth indices were significantly (p < 0.05) improved by increasing in the EMFs intensity. Two mT treatment indicated the highest final weight (43.95 ± 0.27 g), weight gain (6.83 ± 0.10 g), weight gain rate (20.94 ± 0.13 %), daily growth rate (0.38 ± 0.00 g day-1), specific growth rate (1.26 ± 0.01 % day-1) and the lowest food conversion ratio (p < 0.05). Survival rate significantly (p < 0.05) increased in all exposed treatments compared to the control group. In conclusion, ELF-EMF can enhance the growth indices and survival rate of common carp as one of the most commercially-important cultured fish species over the world

Endocrine disrupting effects of 4-nonylphenol on plasma vitellogenin, reproductive system and histology in koi carp (Cyprinus carpio)

This study aimed to assess the effect of 4-nonylphenol (4-NP), a ubiquitous aquatic micro-chemical pollutant substance on some on some reproductive parameters and histology in koi carp. Fish were intraperitoneally subjected to ascending doses of 4-NP at 10, 50 and 100 μg/g body weight (BW) on days 7, 14 and 21 after the initiation of the experiment. Also, one group was treated with 17β-estradiol (E2) at 2 μg/g BW, positive control group (C2) received the vehicle (50 μL of coconut oil + 50 μL Ethanol) per fish and a negative control group (C1) was considered without injection. The results showed that 4-NP induced significantly an increase in E2, progesterone, and plasma vitellogenin at 50 μg/g in both male and female, while level of testosterone significantly decreased in the treated fish compared to control fish (P < 0.05). Conversely, the levels of these parameters at the higher concentration of 4-NP (100 μg/g) were significantly reduced compared to control one (P < 0.05). Also, some sever histopathological changes were observed in ovary, testicular and liver of treated fish, reflecting fish sensitivity to 4-NP at higher doses. This study showed that 4-NP has an estrogenic potency in the sexual development, hepatotoxicity and gonado-toxicity of koi carp

Lactococcosis a re-emerging disease in aquaculture: Disease significant and phytotherapy

Lactococcosis, particularly that caused by Lactococcus garvieae, is a major re-emerging bacterial disease seriously affecting the sustainability of aquaculture industry. Medicinal herbs and plants do not have very much in vitro antagonism and in vivo disease resistance towards lactococcosis agents in aquaculture. Most in vitro studies with herbal extractives were performed against L. garvieae with no strong antibacterial activity, but essential oils, especially those that contain thymol or carvacrol, are more effective. The differences exhibited by the bacteriostatic and bactericidal functions for a specific extractive in different studies could be due to different bacterial strains or parts of chemotypes of the same plant. Despite essential oils being shown to have the best anti-L. garvieae activity in in vitro assays, the in vivo bioassays required further study. The extracts tested under in vivo conditions presented moderate efficacy, causing a decrease in mortality in infected animals, probably because they improved immune parameters before challenging tests. This review addressed the efficacy of medicinal herbs to lactococcosis and discussed the presented gaps

Proximate composition and protein electrophoresis pattern of muscle from black mouth croaker (Atrobucca nibe) in the Oman Sea

Black mouth croaker is considered as a new and valuable resource in the deepwater of the Oman Sea. This study describes the chemical proximate composition, the fatty acid profiles of the fish oil using gas chromatography and phosphorus element (colorimetric method) of the fish muscle. Moreover, the pattern of protein using polyacrylamide gel electrophoresis (SDS-PAGE) was carried out. Proximate composition of the fillet was calculated in wet weight as follow: 79.32±0.299% moisture, 18.19±0.145% protein, 1.01±0.032% fat and 1.434±0.047% ash. The concentration of total saturated fatty acids (SFA), monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) were measured 39.54±0.272%, 37.66±0.161% and 23.56±0.369%, respectively. Among PUFA, concentration of DHA (9.43±0.345%) was obtained more than EPA (1.16±0.051%) (

Determination of grapefruit ( Citrus paradisi ) peel extract bio‐active substances and its application in Caspian white fish ( Rutilus frisii kutum ) diet: Growth, haemato‐biochemical parameters and intestinal morphology

In this study, total phenolic and flavonoid contents of grapefruit peel extract (GPE) were equal to 117.3 ± 0.3 µg of gallic acid/mg and 39.30 ± 0.1 µg of quercetin/mg respectively. Caspian white fish (n = 180, 4 ± 0.9 g body weight) was fed with supplemented diets, including 0, 6.25, 12.5 and 25 mg of GPE/kg for 60 days at 25 ± 1°C. The growth performance was markedly improved in fish fed with 25 mg/kg of GPE compared to others (p < 0.05). Moreover, fish fed with 25 mg/kg of GPE showed a significant increase in red blood cell (2.65·106 cell/mm3), white blood cell (17.75·103 cell/mm3), packed cell volume (48%) and haemoglobin concentrations (8.75 g/dl) compared to the control (p < 0.05). However, the highest alanine aminotransferase (140 U/L), alanine transaminase (14.5 U/L), and alkaline phosphatase (18.5 U/L) were observed in control group. Morphological analysis of intestine revealed the highest amount of villus width (8.4 µM), height (32.86 µM) and surface area (342.7 µM2) in fish fed with 25 mg/kg of GPE (p < 0.05). In conclusion, supplementing feed with GPE at 25 g/kg can improve growth performance and haemato‐biochemical parameters of Caspian white fish fry

Effect of date palm (Phoenix dactylifera)seed extract as a dietary supplementation on growth performance immunological haematological biochemical parameters of common carp

This study aimed to assess the effect of date palm (Phoenix dactylifera) seed (DPS) extract at 0.5%, 1%, 2% and 4% as a dietary supplement over 60 days, on the growth and immune-physiology of common carp (Cyprinus carpio) fingerlings. The weight gain in fish fed with 0.5% DPS was significantly greater than other treatments and fish fed a control diet with no DPS (p < 0.05). With increasing DPS dosage above 0.5%, weight gain and growth rate gradually declined. Feed conversion ratio in fish fed 0.5% DPS was lower than other treatments, but not significantly so, except for the highest DPS concentration (4%). With respect to immunophysiological variables, fish treated with 0.5% DPS leucocyte, neutrophil, lymphocyte and monocyte counts that were generally equivalent to fish on a control diet, but significantly lower than fish treated with greater concentrations of DPS (p < 0.05). Chemilumincene response and lysozyme activity, as well as levels of total protein and albumin, were higher in all treated groups than the control. The highest levels of iron and high density lipoprotein (HDL) were observed in fish fed with 0.5% DPS, while the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP), glucose, cholesterol, triglyceride, low density lipoprotein (LDH), thyrotropin, thyroxine and triiodothyronine were lower level in fish fed with 0.5% DPS than in all other treatments. In aquaculture practice, use of 0.5% DPS in commercial carp feed can improve the growth rate and condition of fish