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The effect of garlic extract on growth and survival rates of one day larvae of Litopenaeus vannamei shrimp was tested for 12 days .Six nutritional treatments each with three replicates were fed to shrimp larvae (average weight 0.0013g) including control treatment (unriched Artemia nauplii) and second to sixth Artemia nauplii enriched with 200, 400, 600, 800 and 1000mg garlic extract per kg, respectively. The one way ANOVA results showed that all treatments were different in terms of average weight and total length of larvae compared to control group. Shrimps being fed by Artesia enriched with 200mg garlic extract per kg food have the best growth, survival rates and length (0.0062mg, 81.6% and 10.6mm). Group 3 with concentration of 400mg garlic extract per kg of feed followed by control group showed better growth and survival rates in shrimp larvae than other treatments but the lowest survival rate evaluated in shrimps fed by Artemia nauplii enriched with 600, 800 and 1000mg garlic extract per kg feed, orderly. Specific growth rates (SGR) for treatment groups 2 and 3 were higher compared to other groups.

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The aim of this reaserch was to study the effect of astaxanthin pigment on growth performance (weight again, specific growth rate and final body weight), survival and pigment accumulation in postlarvae of white leg shrimp. This study was carried out in spring 2011 at Kolahi Aquatic Development Center. Some 8-day postlarvae with mean (±SD) initial weight 5.3±1.6mg were fed diets with containing various levels (0, 50, 100 and 200mg/kg diet) of astaxanthin pigment for 30 days. Shrimp fed with diet without astaxanthin pigment served as control. Shrimp fed diets containing 50, 100 and 200mg/kg astaxanthin, growth performance and survival was significantly higher than control group. The pigment accumulation rate was determined by high performance liquid chromatography (HPLC). The analysis of pigment accumulation showed that the higher increasing astaxanthin pigment amount in the diets, the higher growth performance and survival rate in postlarvae as in postlarvae fed with 200mg astaxanthin/kg, final weight (700.6±12.7mg) and survival rate (82±1.5%) was significantly higher than control group (484.2±28.9, 54.7±4.5% final weight and survival rate, respectively). Due to nutritional properties of astaxanthin pigment and the positive effect on growth and survival, the feeding of postlarval white leg shrimp with the diet containing at least 100mg astaxanthin/kg is recommended. *Corresponding author

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The aim of the present study was to evaluate alpha lipoic acid (ALA) supplementation as an antioxidant source. In this experiment, rainbow trout with average weight of 22.16 ± 0.02 g were studied in four treatments with three replications for eight weeks. Experimental diets included control (non-supplemented commercial diet), 500 mg/ kg ALA, 1000mg/ kg ALA and diets containing 1500 mg/ kg ALA. After eight weeks, growth parameters, fish muscle composition, levels of glutathione-S-transferase (GST), glutathione (GSH) and catalase (CAT) activity were measured in muscle, liver and intestine. The results of growth factors showed that percentage of weight gain, length increase and specific growth rate were significantly (p<0.05) different between treatments and highest in 500 and 1000 mg/ kg ALA. Results of rainbow trout carcass fed with ALA showed a significant difference in protein and dry matter (p<0.05), and treatment containing 1500 ALA concentration showed the highest carcass protein and dry matter. In addition, the effect of different concentrations of alpha lipoic acid on the activity of GST, GSH and CAT enzymes in muscle, liver and intestinal tissues was significant (p<0.05). In muscle, CAT increased with increasing ALA concentration. Also, the highest and lowest amounts of GSH and GST were observed at 1000 and control concentrations, respectively. In the intestinal and liver tissues, the activity of GSH, GST and CAT enzymes was higher in treatments containing ALA. Considering the results of growth, increase of carcass protein and improvement of antioxidant enzymes activity by ALA, it is recommended to use this supplement at a concentration of 1000 mg/ kg. 

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The present study aimed to investigate the effect of the commercial probiotic BetaPlus^® Ultra (BP Ultra) in combination with the galacto-oligosaccharide (GOS) or the isomalto-oligosaccharide (IMO) prebiotics in Caspian trout (Salmo caspius) parr. S. caspius (8.5±0.07 g) was randomly distributed in three dietary treatments including: control group, synbiotic treatment I (0.1% BP Ultra + 0.2% GOS) and synbiotic treatment II (0.1% BP Ultra + 0.2% IMO) and in nine 300 L circular polyethylene tanks with three replications per treatment and, then, fed for seven weeks. At the end of this experiment, growth performance and hepatosomatic index improved significantly in both synbiotic treatments compared to the control group (p<0.05). However, the trend of this improvement was more noticeable in the synbiotic treatment I compared to the synbiotic treatment II without any significant difference (p>0.05). The counts of red and white blood cells in the both synbiotic treatments were significantly decreased and increased compared to the control group, respectively (P<0.05). The values of hemoglobin, packed cell volume, and mean corpuscular hemoglobin in the synbiotic treatment I showed significant increases compared to the synbiotic treatment II (P<0.05). The highest significant levels of crude protein and lipid in carcass were observed in the synbiotic treatment II and the synbiotic treatment I, respectively (P<0.05). Dry matter of carcass was increased significantly in the synbiotic treatment I compared to the synbiotic treatment II (P<0.05). The lowest ash content of carcass was observed in the synbiotic treatment I with a significant difference compared to the synbiotic treatment II and the control group (P<0.05). The results of the present study demonstrated the remarkable efficiency of the synbiotic treatment II on the protein increase and lipid reduction in carcass, although the synbiotic treatment I had a better effect on growth performance and hematological parameters in S. caspius.

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This study was conducted to evaluate the effect of different concentrations of selenium and zinc nanoparticles on growth performance, survival and chemical composition of Whiteleg shrimp (Litopenaeus vannamei). For this purpose, shrimp with an average weight of 5.1±0.2 g were distributed in 12 fiberglass tanks with 25 shrimp density and were fed for 56 days with different concentrations of selenium and zinc nanoparticles in four groups with three replicate including 0 (control), T₁ (0.3 mg/kg of selenium nanoparticl), T₂ (0.15 mg/kg of selenium nanoparticle+ 15 mg/kg of zinc nanoparticl) and T₃ ( 30 mg/kg of zinc nanoparticl). Based on these results, weight gain increasing, specific growth rate and feed conversion ratio in T₂ treatment compare to T₁, T₃ and control treatments (p<0.05). Also, there is significant differences in survival rate between T₁ and T₂ treatments compared to T₃ and control (p<0.05). Statistical analysis showed that there was a significant difference in protein and lipid carcass percentage between shrimp-fed diets containing different levels of selenium and zinc nanoparticles compared to control treatment. In general, the effect of different concentrations of selenium and zinc nanoparticles, especially in the T₂ on growth performance, survival and chemical composition was positively and significantly evaluated.

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The aim of this study was to investigate the effects of dietary ethanol extract of Rhizophora mucronata leaves on the growth performance, survival, and biochemical composition of Litopenaeus vannamei. The experiment was conducted using 600 shrimp juveniles (2 g) in a completely randomized design with four treatments and three replicates, with 50 shrimp per replicate for a duration of 60 days. The experimental treatments included: 1- Basal diet (control), 2- Basal diet + 1 mg ethanol extract of mangrove leaves, 3- Basal diet + 2.5 mg ethanol extract of mangrove leaves, and 4- Basal diet + 5 mg ethanol extract of mangrove leaves. At the end of the experimental period, various growth, biochemical, and survival parameters were measured. The results showed that body weight gain, daily growth rate, and specific growth rate were significantly higher in the 1, 2.5, and 5 mg/kg ethanol extract of mangrove leaves compared to the control group (P<0.05). The highest carapace length was mesured in 2.5 mg/kg compared to the other experimental groups (P<0.05). Besides, the survival rate was significantly increased in all extract treatments compared to the control group (P<0.05). The highest crude protein content of the carcass and the lowest moisture content were observed in 2.5 mg/kg (P<0.05). The control group showed the lowest lysozyme activity, while the 5 mg treatment exhibited the highest lysozyme activity, followed by the 1 mg and 2.5 mg treatments (P<0.05). The 1 mg treatment showed the highest phenoloxidase activity (P<0.05). Based on the results, the 2.5 mg and 5 mg treatments were associated with the highest protein and albumin contents, while the control and 1 mg treatments had the lowest contents (P<0.05). Overall, it can be concluded that the inclusion of 2.5 mg/kg of mangrove leaf extract in the diet had positive effects on the growth, biochemical composition, and survival of whiteleg shrimp.