Effects of different levels of dietary glucosamine on some growth performance, serum immune and biochemical indices of Siberian sturgeon (Acipenser baerii)

This study was performed to evaluate the effects of different dietary levels of glucosamine on growth performance, serum biochemical and immune indices of Siberian sturgeon. Fish (9.3 ± 0.4 g initial weight) in 12 fiberglass tanks with a density of 15 fish/tank were randomly distributed and fed with different levels of glucosamine including: 0 (control), 250, 750 and 1500 mg per kg of diet (C0, T250, T750 and T1500, respectively) for 56 days. Based on the results, the highest final weight (63.1 ± 1.6 g), weight gain (54.14 ± 1.82 g), body weight increase (558.28 ± 23.23%), and specific growth rate (3.36 ± 0.08%/day) were observed in T1500 compared to the other treatments (p 0.05). The results of the serum immune indices exhibited that the highest levels of IgM (38.1 ± 0.5 mg/dL), C3 (5.20 ± 0.17 mg/dL) and C4 (20.72 ± 1.0 mg/dL) were observed in T1500 compared to other experimental treatments (p < 0.05). On the other hand, by increasing glucosamine concentration, the activity of hepatic enzymes including aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase was decreased and the lowest levels were observed in T1500 (p < 0.05). In conclusion, glucosamine, especially at the level of 1500 mg/kg of diet, displayed positive effects on the growth and immune indices of juvenile Siberian sturgeon

Dietary effects of lemon Citrus limon peel essential oil encapsulated in chitosan nanoparticles on hematological indices and antioxidant defense system of rainbow trout Oncorhynchus mykiss

This study was conducted to evaluate the effect of dietary levels of lemon essential oil encapsulated in chitosan nanoparticles on hematological indices and antioxidant status of rainbow trout fry. Accordingly, the fish (4.74 ± 0.14 g in weight) were distributed in 12 fiberglass tanks with 20 fish per tank and were fed with different levels of lemon essential oil loaded in chitosan nanoparticles including control group with no additive (C0%), 0.5% (T0.5%), 0.75% (T0.75%) and 1% (T1%) for 8 weeks in triplicates. The results showed that the highest number of RBC was in T0.75% compared to T0.5% and C0% (p<0.05). The maximum hemoglobin value was observed in T1% and T0.75% compared to the other experimental groups (p<0.05). In addition, in terms of the blood indices, MCH index showed a significant increase in T1% and T0.75% compared to the other treatments. The maximum WBC and lymphocytes were observed in T1% compared to the other experimental groups (p<0.05). Serum antioxidant enzymes showed the highest catalase activity and glutathione peroxidase in T1% compared to the other groups (p<0.05). Furthermore, superoxide dismutase activity elevated significantly only in T1% compared to C0% (p<0.05). However, the oral administration of 0.75% and 1% of lemon peel essential encapsulated with nanochitosan resulted in a significant elevation in the serum malondialdehyde compared to T0.5% and C0% (p<0.05). Overall, the results of this study showed that the addition of lemon essential oil encapsulated in chitosan nanoparticles, especially at 1%, can enhance the hematological indices and antioxidant defense system of rainbow trout

Effect of a Peracetic Acid-Based Disinfectant on Growth, Hematology and Histology of Juvenile Rainbow Trout (Oncorhynchus mykiss)

The effects of a peracetic acid-based disinfectant product (Aquastart®) were assessed on some hematological parameters, histological aspects and skin bacterial load of rainbow trout, likewise bacterial load of the rearing tank water. A total of 180 healthy rainbow trout weighing 124.65 ± 10 g were divided into two groups, each in three replicates in flow-through tanks. First group was exposed to Aquastart at 8.9 ppm for 30 min and second group was considered as the control. The fish were then reared for 60 days prior to sampling for hematological and histological studies. The lowest bacterial load level in both water columns and trout skin were observed in the treated trout (p &lt; 0.05). Meanwhile, no significant impact on growth performance was recorded between treated and control fish. The immunocompetent cells population size in control fish were significantly lower than treated fish (p &lt; 0.05). Histologically, no evidence of abnormality was seen in the gills, kidney, and liver tissues of treated fish. These results showed that application of Aquastart at 8.9 ppm is safe for use in flow-through tanks farming rainbow trout

Study of cultured rainbow trout contamination with Streptococcus iniae and Lactococcus garvieae in some fish markets of Tehran and Karaj(orginal reserch article)

Streptococcosis is one of the economically important diseases in the aquaculture industry particularly in rainbow trout aquaculture causing remarkable annual losses. Streptococcosis is known as a zoonotic disease causing morbidity and mortality in some consumers. In this study the status of farmed rainbow trout contamination with Streptococcus iniae and Lactococcus garvieae was assessed. For this reason, during summer months, 64 apparently diseased trout were sampled from fish markets of Tehran and Karaj. Gram staining was performed on grown colonies and then gram-positive cocci were further characterized using biochemical and PCR assays. The obtained results showed that 56.23% (36 samples) of the samples were infected with the both bacterial pathogens. The prevalence of S. iniae and L. garvieae were 32.8 % (21 samples) and 23.43% (15 samples), respectively. The highest and lowest prevalence rate of S. iniae was observed in the samples of Karaj (15.62%) and Kahrizak (0%) markets, respectively. In the case of L. garvieae, the highest and lowest rates were obtained in Karaj/Kahrizak (7.81%) and Meidan-Nabi (1.56%) markets, respectively. The results revealed that in some markets, the prevalence of streptococcosis and lactococcusis in cultured rainbow were relatively high. Therefore, it is necessary to conduct further trials

Assessment of dietary chaste tree (Vitex agnus-castus) fruit extract on growth performance, hemato-biochemical parameters, and mRNA levels of growth and appetite-related genes in goldfish (Carassius auratus)

In this study, the effect of oral administration of chaste tree fruit (CTF) extract was evaluated on growth performance, hematological indices, serum biochemical parameters, and the expression of growth and appetite-related genes in goldfish (Carassius auratus). The fry (N = 300; 2.40 ± 0.12 g) were randomly dispersed into 12 aquaria and fed with different levels of CTF extract (0 (control), 0.5%, 1.0%, and 1.5%) for 56 days. At the end of the trial, the highest body weight gain and the lowest feed conversion ratio were observed in the fish fed with 1.5% CTF extract (P  0.05). The levels of aspartate transaminase and lactate dehydrogenase were decreased by increasing the supplementation levels of CTF extract and the lowest values were obtained in 1.5% CTF extract diet (P < 0.05). The expression of growth hormone, insulin-like growth factor 1, and ghrelin genes was significantly up-regulated in the fish fed with 1.5% CTF extract compared to other treatments (P < 0.05). Overall, the enrichment of goldfish diet with 1.5% CTF extract could interfere positively in the growth-related traits and hematological parameters

Dietary green-synthesized curcumin-mediated zinc oxide nanoparticles promote growth performance, haemato-biochemical profile, antioxidant status, immunity, and carcass quality in Nile tilapia (Oreochromis niloticus)

This study evaluated the effect of dietary curcumin-assisted green synthesized zinc oxide nanoparticles (CUR-ZnONPs) on growth performance, haemato-biochemical profile, antioxidant capacity, immune response, carcass composition, and bioaccumulation of Zn in Nile tilapia. The fish (‎16.20 ± 1.02 g‎) were fed with diets enriched with 0 (CZP1), 5 (CZP2), 7.5 (CZP3), and 10 (CZP4) mg/kg CUR-ZnONPs for 56 days and then challenged with Aeromonas hydrophila. The highest growth performance (final weight, weight gain, and specific growth rate) and the lowest feed conversion ratio were recorded in CZP4 (P  0.05). The mortality rate of the fish infected with A. hydrophila was significantly lower in the group that received CZP4 compared to the other experimental groups (P < 0.05). The principal component analysis demonstrated that the fish fed with CUR-ZnONPs have significantly higher growth performance, immune responses, and antioxidant status than the fish fed with the control diet. Overall, it is suggested to use dietary CUR-ZnONPs, especially at 10 mg/kg, as a beneficial feed supplement to improve growth performance, antioxidant status, and immune parameters in Nile tilapia