JOURNAL OF AQUATIC ANIMALS NUTRITION
Year:2019 | Volume:4 | Issue:2|Papers Count:6

This study was conducted to evaluate the effects of two commercial prebiotic and probiotic called Behsam and Behsil, respectively, in feeding performance, ammonia and urea excretions as well as energy losses in grass carp, Ctenophryngodon idella fry. Three levels of Behsam and Behsil (200, 400 and 600 mg/kg of diet) were supplemented to experimental diets and fed to grass carp fry (initial weight of 625. 15 ± 10. 12 mg). The present study was conducted in a completely randomized design. At the end of experiment, the fish final weight, food conversion ratio, protein and lipid efficiency ratio of the grass carps fed supplemented diet with different levels of Behsam and Behsil had significantly difference with control group (p<0. 05). The results clearly exhibited that the different levels of Behsam and Behsil had positive effects on the ammonia and urea excretions in fish fry and also the energy decreasing rate in experimental treatments in comparison with control group. Minimum of ammonia-N and urea-N excretions were obtained in treatment Behsam 600. The maximum energy losses via excretion of ammonia and urea were obtained in control. However, the minimum energy losses were obtained in fish fry fed with 600 mg/kg Behsam. The total energy losses by nitrogenous wastes such as ammonia, urea and energy losses rate (%) per energy intake were decreased in the various experimental treatments in comparison with control. Maximum energy expenditure was detected in control group, but it decreased in experimental treatments and minimum value was obtained in treatment containing 600 mg/kg Behsam. In this study, it was found that the various Behsam and Behsil levels in rearing grass carp fry exhibit different effects on feeding performance, ammonia and urea excretions as well as energy losses in this fish.

This study aimed to introduce new protein sources to replace fish powder in diets for rainbow trout, Oncorhynchus mykiss. In this study, fish powder protein was replaced with the typical Kabuli chickpea (Cicer arietinum) and irradiated pea seeds in the diet followed by assessing their effects on growth and nutritional indices, digestion and body composition of rainbow trout. The study was conducted in the Artemia and Aquatics Propagation Research Institute, University of Urmia, Urmia, Iran. 720 juvenile O. mykiss (60 ± 4 g) were randomly divided equally into eight treatments with three replicates, and were fed with experimental diets for 60 days. The experimental diets were commercial food, homemade food without pea (control), typical pea diets containing 20, 30 and 40% and diets containing 20, 30 and 40% irradiated pea. The results showed that radiation has not significantly affected the food ingredients of peas (protein, fat and dry matter) and growth parameters (P>0. 05), but there were significant changes in nutritional indicators and digestibility of the diet along with increasing the percent of peas replacement (P<0. 05). As a result, the increase in radiation as well as 40% peas in the diet of O. mykiss did not exhibit negative impact on growth performance. Therefore, the irradiated pea protein can be a good food item to replace fish powder in the fish diet.

The aim of this study was to investigate the effects of different levels of Celmanax commercial prebiotic on growth performance, nutritional efficiency, blood and plasma biochemical indices in beluga, Huso huso (Linnaeus, 1758) in a 120-day feeding period. So that, 120 individuals of beluga with the average weight of 4. 66 ± 0. 26 kg were transferred to 12 holding cage nets, 1. 20 × 1 × 2 m in size at a depth of 1. 5 m with a completely randomized design as four treatments with three replications including control (without prebiotic) and three experimental treatments fed by diets containing 0. 5, 1, 1. 5 g/kg prebiotic. The results exhibited that adding Celmanax to the diet, especially 0. 5 g/kg, significantly enhanced relative weight, daily growth rate, specific growth rate, feed conversion ratio and relative eating (p<0. 05). However, no significant effect was observed in the protein and fat ratio (p>0. 05). There were also no significant differences between the treatments fed by prebiotic compared to control with respect to hemoglobin, mean corposcular volume and mean corpuscular hemoglobin (p>0. 05). Analyses on biochemical indices indicated that there were significant differences in total protein, glucose and triglyceride in blood plasma levels. Totally, according to the results, 0. 5 g/kg Celmanax in diet can effectively enhance growth performance, nutritional efficiency and blood indices in cultured beluga.

Gamma irradiation is one of the most suitable methods for enhancing shelf-life of fish and fishery products. In this study, the effect of gamma irradiation (0, 3 and 4 kGy) in combination with edible coating by basil gum (2%) and marjoram (2 and 4%) extracts on the chemical properties of Ship sturgeon, Acipenser nudiventris fillets were examined under refrigerated storage (25 days). Radiation affected all examined indices. The results exhibited that the pH and TVB-N values in irradiated samples were lower than in the non-irradiated fish (p<0. 05(. The lowest and highest values of pH and TVB-N were found in control samples and treatments coated with 2% basil gum, 4% extract and 4 KGy gamma ray, respectively. The treatment contained 2% basil gum had a lower content of TBARS values (p<0. 05). Among all treatments, the lowest change in WHC was recorded in the samples which were coated with basil gum 2% and marjoram extract 4% and irradiated with 3 kGy. According to the obtained results, using gamma radiation in combination with basil gum and marjoram extract can increase the shelf-life of Ship sturgeon fillets.

The present study aimed to determine the effects of four experimental diets on growth, immunological parameters, and coloration of the white Oscar, Astronotus ocellatus (Agassiz in Spix and Agassiz, 1831). So that, 120 individuals, with an average weight of 7. 5 ± 0. 5 g, were randomly distributed in 12 aquaria (10 fish in each aquarium). The fish were fed with 4 diets as follows: pigment-free (as the control), astaxanthin, turmeric powder, and spirulina powder (100 mg kg-1 ) for eight weeks. At the end of the experiment, growth and immunological indices, as well as coloration were measured. There was a significant difference between control and the astaxanthin treatment in all growth indices except for condition factor (p<0. 05). There were also significant differences between control and the spirulina treatment in the survival rate and growth rate; between control and the turmeric treatment in the increased length; and between control and turmeric and spirulina treatments in food conversion ratio (p<0. 05). The results also indicated that there was a significant difference between the astaxanthin treatment and other treatments in lysozyme activity as well as between control and the spirulina treatment in terms of IgM level (p<0. 05). However, such a significant difference was not observed in total immunoglobulin and total carotenoids (p>0. 05). There was a significant difference between some treatments in the intensity of primary and secondary colors (p<0. 05). The findings exhibited that all three types of pigments employed in this study could improve the growth factors, immunological parameters, and coloration of white Oscar; however, astaxanthin outperformed the others.

The present study was conducted to evaluate the effect of probiotic bacteria Lactobacillus rhamnosus encapsulated with alginate and resistant starch (Hi maize) coated by chitosan on the growth and hematological indices as well as carcass composition in rainbow trout (Oncorhynchus mykiss). Rainbow trout fingerlings averaged 19. 49 ± 0. 32 g in weight were fed with diets containing encapsulated probiotic, free probiotic, and diet containing capsules without bacteria (positive control) as well as control diet without probiotics for 60 days. The results exhibited that there were significant differences in growth rate, weight gain, specific growth rate and feed conversion ratio in different groups. So that, the best results were obtained in the encapsulated probiotic group (p<0. 05). The maximum carcass protein and fat were observed in the encapsulated L. rhamnosus treatment, while the maximum carcass ash was in control (p<0. 05). The hematocrit and hemoglobin values in the encapsulated probiotic treatment were higher than in control. No significant differences were found in the number of white and red blood cells as well as MCV, MCH and MCHC (p>0. 05). Totally, the results suggest that encapsulation of L. rhamnosus can increase the potential for probiotic employing in aquaculture.