Interspecies variation in the hepatic biotransformation of zearalenone: Evidence for bio-inactivation of mycoestrogen zearalenone in sturgeon fish

Zearalenone (ZEA) as mycoestrogen is found in human foods and animal feeds. Its estrogenic potency depends on its biotransformation fate. The hepatic biotransformation of ZEA in two species of sturgeon fish (Acipenser persicus and Huso huso) was investigated. ZEA was incubated with the hepatic microsomal and post-mitochondrial sub-fractions in the presence of NADPH and the metabolites were determined by means of HPLC. Moreover, the rate of glucuronidation for ZEA and its metabolites were estimated in the presence of uridine diphosphateglucuronic acid. β-zearalenol (β-ZOL) was found to be the major metabolite of ZEA by both sub-fractions. Enzymatic kinetics studies revealed that the maximum velocity (Vmax) in microsomal and post-mitochondrial fractions for β-ZOL production was found 5- and 7-folds in Huso huso and 8- and 12-folds in A. persicus higher than that for α-ZOL production, respectively. The H. huso hepatic post-mitochondrial fraction mainly glucurinated ZEA while in A. persicus, the metabolites and in particular β-ZOL were glucuronidated. Data suggest that the hepatic biotransformation of ZEA in studied sturgeons resulted in detoxification of ZEA as the main metabolite tends to be β-ZOL with weaker estrogenic property. Moreover, clear differences in glucuronidation profile are indicating interspecies variety in hepatic biotransformation of ZEA

Optimizing the technique for replacement of unicellular algae with agricultural by-products in feeding Artemia urmiana and parthenogenetic Artemia

In order to assess the maximum replacement possibility of unicellular green algae with cheap food sources for feeding Artemia, two strains of Artemia urmiana and parthenogenetic Artemia were fed under laboratory condition using wheat bran, soybean meal and 50/50% mixed diet of wheat bran/soybean, each in 12 different concentrations together with different rations of Dunaliella salina for 15 days. The results were compared with those fed only on algae D. salina as control group. At the end of the experiment, control groups in each two strains (with 9.11mm growth and 86.25% survival in A. urmiana and 8.55mm growth and 85% survival in parthenogenetic Artemia) had almost the best condition. In A. urmiana treatments 95.8-88% replacement for algae of wheat bran, treatment 94% replacement for algae of soybean and treatments 97-94% replacement for algae of mixed wheat bran/ soybean showed no significant differences with control in both growth and survival. In parthenogenetic Artemia treatments 94-82% replacement for algae of wheat bran, treatments 91-88% replacement for algae of soybean and treatments 91-82% replacement for algae of mixed wheat bran/soybean showed no significant differences with their control in both growth and survival. According to the results, it seems that single-cell algae and their production requires exorbitant spending and personnel which can be replaced with easily affordable agricultural wastes, without need to specialized staff

Hatchability and biochemical composition of Artemia urmiana's nauplii at different incubation times

Hatchability of cysts and nutritional value of Artemia urmiana's nauplii in different incubation times were evaluated. The experiments were conducted at five incubation times 18, 20, 22, 24 and 26 hours, in triplicate random groups. Hatchability of cysts during these periods was determined with standard methods. Nauplii were hatched in five litre bottles to determine their biochemical composition. Dry weight, protein, lipid, carbohydrate, ash, caloric content and fatty acid compositions of naupiiies were determined at different developmental stages. Also, the dry weight and the biochemical composition of nauplii were determined individually, at different develop-mental stages. The results showed that the hatching percentage and efficiency increased with time with the hatching percentage being significant (P0.05). Based on the results, the incubation times 25 or 26 hours are recommended for harvesting nauplii. At these times, hatchability and the amount of harvested nauplii increased while their nutritional value was highest

Comparison of the digestive enzyme activities in Artemia urmiana from nauplii to adult stages using different diets

Due to the importance of adult Artemia in aquaculture, information regarding the digestive enzyme activities variation with inexpensive diets has great importance in Artemia at different life stages. In this study, the effect of different inexpensive diets on digestive enzyme activities, including trypsin, amylse and lipase of Artemia urmiana was investigated in different life stages. The experiment was carried out with 5 treatments and each with 2 replicates over 15 days using 5 diets (wheat meal, common carp diet, soy meal, a mixture of soy meal and canola meal (compound diet 1) and a mixture of soy meal and wheat meal (compound diet 2) in a completely random design. Nauplii were introduced to their cultivation environments after hatching and the digestive enzyme activities were measured in days 5, 10 and 15 of the experiment. Positive and significant correlation were observed between the crude protein content of the diets and trypsin activity (0.74), the carbohydrate content of the diets and amylase activity (0.49), and crude fat content of the diets and lipase activity (0.84). The activities of all enzymes were increased with the Artemia development in this study. During the experimental period, the trypsin, activities were increased in all treatments with the exception of wheat meal treatment, amylase activities were increased in all treatments and lipase activities were increased in all treatments with the exception of common carp diet and wheat meal treatments. Digestive enzyme activities were affected by the diets and Artemia life stages. Regarding the increasing digestive enzyme activities until adult stage in Artemia urmiana, using adult Artemia urmiana decreases pressure on resources of Artemia cyst and nauplii in natural environments. In addition, this condition may result in more economic returns and better quality of adult Artemia compared to its cyst and nauplii

Nutritional enhancement of total lipid, n-3 and n-6 fatty acids in Artemia urmiana nauplii by enriching with ICES/30/4

Artemia urmiana nauplii were enriched with three different concentrations (100, 200 and 300 ppm) of commercial emulsion, ICES/30/4 during two periods (12 and 24 h) to evaluate the enhancement of its Highly Unsaturated Fatty Acids (HUFAs). This source was selected because of its high concentration of the longest chain HUFA's in the n-3 and n-6 series. When 24-h-old Artemia nauplii were enriched with 100 ppm concentration of ICES30/4 during 12 h enriching period, the docosahexanoic acid (DHA), eicosapentaenoic acid (EPA) and arachidonic acid (ARA) contents of the nauplii increased to 0.77, 1.22 and 0.34 and when enriched with 300 ppm during 24 h increased to 5.99, 4.97 and 0.73 mg g(-1) dry weight, respectively. DHA, EPA and ARA in control nauplii were 0.00, 0.82 and 0.61 mg g(-1) dryweight, respectively. Total lipid increased from 16.79% in control group to 20.87% in the treatment ICES30/4 24-300. The results suggest that high amount of emulsion and prolong the enriching period are effective in enriching Artemia nauplii in both DHA and EPA increasingly (p < 0.05) but in other fatty acids, there are differences only among period treatments (p < 0.05) and concentration are not any increasing effective. There are only differences among concentration treatments in total lipid p < 0.05) and enriching period do not show any differences

Effect of feeding rainbow trout larvae (Oncorhynchus mykiss) with Artemia nauplii enriched with vegetable oils on resistance against O2, salinity and temperature stresses

Chronic stresses can influence the behavioral and physiological activities of animals and can lead to reduction of resistance against disease and decrease in growth rate and production.Artemianauplii enriched with essential nutrients particularly fatty acids have been used to promote growth, survival and resistance of different species of aquatic animals to various environmental stresses as well as infectious diseases. In this study we investigated the resistance to environmental stress (temperature, salinity and hypoxi) in larvae of rainbow trout fed Artemianauplii enriched with vegetable oils. The experiment was carried out in 6 triplicate treatments for a period of 10 days. The feeding treatments included: 1) commercial starter feed for trout (Control) 2) Artemianauplii enriched with fish oil, 3) Artemianauplii enriched with sunflower oil, 4) Artemianauplii enriched with canola oil, 5) Artemianauplii enriched with soybean oil and 6) newly hatched nauplli of Artemia. The results showed significant differences in tolerance of fish larvae to high temperature (20 and 25°C), hypoxia stress (5 ppm) and salinity stress (10, 15 and 20 mg.l-1) among different groups. Highest survival to all experimental stresses (except in one case) was observed in larvae fed Artemianauplii enriched with canola oil compared to those fed control diet ( p<0.05), but in most cases not significant with larvae fed Artemianauplii enriched with fish oil

Replacement of dietary fish meal with plant sources in rainbow trout (Oncorhynchus mykiss); effect on growth performance, immune responses, blood indices and disease resistance

The aim of this study was to examine the effects of replacing fish meal with plant sources on growth performance, immune responses, hematological parameters and disease resistance in rainbow trout. In this study, mean of initial body weight of fish was 15±2 g and the experiment was carried out for a period of 60 days. Four experimental diets were formulated to replace 0, 40, 70 and 100% fish meal with plant protein sources (wheat gluten, corn gluten and soybean meal). According to results, higher plant protein inclusions (70 and 100%) resulted in undesirable effects on growth, nutritional indices, serum total immunoglobulin and alternative complement activity (P 0.05). Furthermore, replacement of fish meal with plant sources in all treatments had no significant effects on blood parameters (hematocrit, hemoglobin, white blood cells, hetrophil and lymphocytes count). Finally, no significant differences were observed in fish mortality after 15 days of challenges with Yersinia ruckeri among treatments (P > 0.05)

A comparative study of proximate composition of Artemia urmiana enriched with different sources and levels of HUFA

The nutritional quality of commercially available Artemia strains is relatively poor in Eicosapentaenoic acid (EPA), Arachidonic acid (ARA) and especially Docosahexaenoic acid (DHA). Hence, it is essential and common practice to enrich this live prey with emulsions of special oils. One commercial ICES30/4 (Belgium), Linseed oil as a vegetable oil, Cod liver oil and Sturgeon ovary oil as two animal oils with EPA amounts in these oils were 6.29, 0.03, 11.39, 7.55 and the DHA amounts were 20.90, 0.00, 7.64, 2.76 respectively with three concentrations (100, 200 and 300ppm) during two enrichment periods (12 and 24h) were tested in order to improve the HUFA content, the DHA/EPA ratio and ARA content of Artemia urmiana nauplii. The results showed that Artemia enriched with different levels of vegetable oil and enrichment periods was poor in relation to either HUFA content or DHA/EPA ratio but the fish oils and emulsion resulted in HUFA incorporation. Sturgeon ovary oil caused the poorest DHA/EPA ratio enrichment (0.40 in 300ppm-24h) but the commercial emulsion (ICES30/4) was found as the best for DHA/EPA ratio enrichment (1.20 in 300 ppm- 24h). Cod liver oil (0.53 in 100ppm-24h) can be a good internal source substitute for improving the DHA/EPA ratio enrichment compared to ICES30/4 due to price and availability. As a result, HUFA content was increased with enrichment level 200ppm during 24h. Also, all oil sources improved lipid and protein percentages in A. urmiana nauplii

Comparison of the growth, survival and nutritional value of Artemia using various agricultural by-products and unicellular algae Dunaliella salina

Because of limitations of production of unicellular green algae (especially in large volumes), this study aimed to culture Artemia using three sources of cheap agricultural by-products that were coupled with small amounts of unicellular algae Dunaliella salina. The results of growth and survival, biomass production, individual wet weight, wet and ash percent, FCR and SGR and nutritional value of experiments groups were compared with that of the control group that was reared on a diet completely consisting of green algae. At the end of day 15, although best results in the case of growth and survival and biomass production were obtained in the control, the results of all evaluated parameters experimental treatments were comparable to the control