Effect Of Artificial Diets Research Articles

Effects of artificial diets on lipid and glucose metabolism, antioxidative capacity, and inflammation in the liver of mandarin fish (Siniperca chuatsi)

The mandarin fish (Siniperca chuatsi) is a typical carnivorous fish, which has been able to consume artificial diets after domestication in recent years. However, the potential health consequences of artificial diets in mandarin fish remain unclear. This study aimed to elucidate the molecular mechanisms underlying these concerns. Fish (initial weight: 25.1 ± 0.1 g) were fed with natural (CON group) or artificial diets (AF group) for 8 weeks. Each diet was randomly distributed to sextuplicate circular tanks (300 L) with 40 fish in each tank. The transcriptome analysis revealed significant changes in metabolism-related pathways, particularly those involved in lipid and carbohydrate metabolism. Further investigation confirmed that the artificial diets significantly increased hepatic triglyceride content and fatty acid synthase activity. The artificial diets also significantly increased hepatic glycogen and glucose-6-phosphatase activity. Furthermore, the artificial diets significantly increased hepatic malondialdehyde levels, indicating increased oxidative stress. Antioxidant defense enzyme activities and the expression of antioxidant stress-related genes were significantly decreased. Additionally, the artificial diets significantly increased the expression of proinflammatory genes, including interleukin 1 beta and interferon-gamma. These findings collectively demonstrated that the artificial diets disrupted hepatic lipid and glucose metabolism, leading to oxidative stress and inflammation, thus affecting the health status of mandarin fish.

The Effects of Artificial Diets on the Expression of Molecular Marker Genes Related to Honey Bee Health.

Honey bees are commonly used to study metabolic processes, yet the molecular mechanisms underlying nutrient transformation, particularly proteins and their effects on development, health, and diseases, still evoke varying opinions among researchers. To address this gap, we investigated the digestibility and transformation of water-soluble proteins from four artificial diets in long-lived honey bee populations (Apis mellifera ligustica), alongside their impact on metabolism and DWV relative expression ratio, using transcriptomic and protein quantification methods. Diet 2, characterized by its high protein content and digestibility, was selected for further analysis from the other studied diets. Subsequently, machine learning was employed to identify six diet-related molecular markers: SOD1, Trxr1, defensin2, JHAMT, TOR1, and vg. The expression levels of these markers were found to resemble those of honey bees who were fed with Diet 2 and bee bread, renowned as the best natural food. Notably, honey bees exhibiting chalkbrood symptoms (Control-N) responded differently to the diet, underscoring the unique nutritional effects on health-deficient bees. Additionally, we proposed a molecular model to elucidate the transition of long-lived honey bees from diapause to development, induced by nutrition. These findings carry implications for nutritional research and beekeeping, underscoring the vital role of honey bees in agriculture.

Selective Elimination of Wolbachia from the Leafhopper Yamatotettix flavovittatus Matsumura.

Wolbachia infections affect the reproductive system and various biological traits of the host insect. There is a high frequency of Wolbachia infection in the leafhopper Yamatotettix flavovittatus Matsumura. To investigate the potential roles of Wolbachia in the host, it is important to generate a non-Wolbachia-infected line. The efficacy of antibiotics in eliminating Wolbachia from Y. flavovittatus remains unknown. This leafhopper harbors the mutualistic bacterium Candidatus Sulcia muelleri, which has an important function in the biological traits. The presence of Ca. S. muelleri raises a major concern regarding the use of antibiotics. We selectively eliminated Wolbachia, considering the influence of antibiotics on leafhopper survival and Ca. S. muelleri prevalence. The effect of artificial diets containing different doses of tetracycline and rifampicin on survival was optimized; high dose (0.5mg/ml) of antibiotics induces a high mortality. A concentration of 0.2mg/ml was chosen for the subsequent experiments. Antibiotic treatments significantly reduced the Wolbachia infection, and the Wolbachia density in the treated leafhoppers sharply declined. Wolbachia recurred in tetracycline-treated offspring, regardless of antibiotic exposure. However, Wolbachia is unable to be transmitted and restored in rifampicin-treated offspring. The dose and treatment duration had no significant effect on the infection and density of Ca. S. muelleri in the antibiotic-treated offspring. In conclusion, Wolbachia inY. flavovittatus was stably eliminated using rifampicin, and the Wolbachia-free line was generated at least two generations after treatment. This report provides additional experimental procedures for removing Wolbachia from insects, particularly in host species with the coexistence of Ca. S. muelleri.

Protein and cellulose level in diet: Effects on enzymatic activity, metabolite and amino acid profiles in freshwater anomuransAegla uruguayana(Decapoda: Anomura)

The aims of this study were to evaluate the short‐term effects of artificial diets with different protein: cellulose ratios (D1 = 60:0, D2 = 45:15 and D3 = 30:30) on the enzymatic activity and metabolite profile and to probe the suitability of the amino acid profile of the different diets in Aegla uruguayana. The different artificial diets affected the digestive total protease and amylase activities in a short period of time. Lipases were not affected by the diets. In the haemolymph, an effect of the diet was found in glucose and triglyceride measurements. Particularly, the glucose of the organisms fed D1 was significantly lower than that of organisms fed D2, without significant differences in D3. The concentrations of triglycerides were different among organisms subjected to the treatments, indicating a greater concentration in organisms fed D2 than in those fed D1. In muscle tissue, the concentration of glycogen followed the same trend as haemolymphatic glucose, indicating that the organisms fed D2 had a higher concentration of this metabolite compared to the rest. The amino acid profile of muscle tissue of wild and fed aeglids had a high and significant correlation in all cases, showing few changes in the short‐term feeding regime. Some changes were observed mainly in aeglids fed D3, which exhibited the lowest amounts of methionine, lysine and arginine and the highest amounts of aspartic + glutamic acids. In addition, D2 has a good quality of EAA, fulfilling almost all the requirements of a wild aeglid.

Effects of artificial diets with different carotene content on the organoleptic characteristics of the gonads and reproductive condition of Loxechinus albus (Echinodermata: Echinoidea)

The organoleptic characteristics of sea urchins gonads (size and color, among others) can be improved by artificial diets. Loxechinus albus is considered one of the most economically significant resources from the littoral-benthic systems in the South Pacific Ocean from Peru to Chile. The objective was to determine artificial diets effects on the organoleptic traits of gonads, reproductive condition, body growth and survival of Loxechinus albus. Two types of diets were administrated (low carotene content diet (LC): balanced food with 0.02% β-carotene and high carotene content diet (HC): balanced food with 0.045% β-carotene) for 16 weeks. As a measurement of growth rate, test diameter of sea urchins fed with artificial diets was measured at the beginning and at the end of the experiment. At both times, size (GI) and color (CI) of the gonads were recorded in ten individuals from each treatment and ten from the natural population (NP). Energy density (ED), energy content (EC) and total carotenes (TCC) were determined by calorimetry and spectrophotometry, respectively. Histological sections were examined microscopically and the sex was identified. Each female was assigned to a gametogenic stage (reproductive condition) and determined: number and diameter of the oocytes, gonadal area occupied by oocytes, and relative frequencies of reproductive stages. At the end of the experiment in relation to the NP, it was possible to achieve higher GI values for both artificial diets. The NP showed higher gonadal area occupied by oocytes and larger oocyte diameter at 16 weeks (P<0.01). In addition, individuals fed with both artificial diets, presented “growth” and “advanced growth” gonad stages (both times), while the NP individuals, presented stages of “prematurity”, “maturity” and “partial spawning” at week 16. The data shows the highest CI value for the HC diet at eight weeks (P<0.01). Moreover, TCC values for the NP were significantly higher at week 16 (P<0.01). Loxechinus albus is an appropriate species to be kept in captivity, as their mortality is very low, facilitating the achievement of long-term experiences of gonadal improvement. According to our data the optimal time to improve the organoleptic characteristics is eight weeks with a high carotene artificial diet, since optimal gonad coloration was reached, and GI values did not differ significantly from the ones achieved at the end of the experiment for both diets, or the ones shown in the NP. This is translated into a lower cost by a reduced cultivation time. Rev. Biol. Trop. 65(Suppl. 1): S207-S220. Epub 2017 November 01.

The effect of artificial diet on the production of alarm pheromone by Myzus persicae

AbstractThe cornicle secretion of Myzus persicae reared on artificial diet only elicits an alarm response in plant‐reared conspecifics after the young aphids have been transferred to plants for 7 days. Acetate in the form of 0.32% sodium acetate has been added to the diet as an early step in synthesis of the alarm pheromone, (E)‐β‐farnesene (EBF). The cornicle secretion of diet‐reared aphids then elicits an alarm response. However, there is no difference in internal EBF concentration between plant‐ and diet‐reared aphids. Puncturing aphids, either plant‐ or diet‐reared, with a pin shows that both can elicit an alarm response, whereas it is reduced by half with diet‐reared individuals. Although there is no significant difference in the concentration of EBF produced, the total amount in diet‐reared aphids is increased by acetate in the diet to a level similar to that in plant‐reared individuals: the size of aphids reared on an acetate‐supplemented diet is increased and comparable with the size of those that are plant‐reared. Bioassays with a range of EBF concentrations show a high threshold for the alarm response. It is concluded that the different size of aphids reared on plants and standard diet results in them secreting, respectively, above and below the response threshold.

Effects of artificial diets on growth and mortality of Rainbow Trout (Oncorhynchus mykiss) larvae

Trout larvae of average weight of 0.08391 to 0.08907 gm were nursed in 12 floating net cages set in a circular tank. The larvae were fed with 4 different diets- Diet 1 (normal diet), Diet 2 (normal diet with buff liver), Diet 3 (normal diet with chicken liver) and Diet 4 (normal diet with mutton liver). The experiment was conducted at completely randomized design (CRD) with three replications for each diet. Body weight, total length and condition factor of larvae did not show significantly variation at different test diets. The specific growth rate was recorded 3.043% per day which was highest in test diet 3. The highest Food Conversion Ratio (FCR) i.e., 2.8768 was recorded in diet 4. Physico-chemical parameters and the survival rate were also recorded. The correlation coefficient of length and weight relationship was highest (0.972) in diet 3. DOI: http://dx.doi.org/10.3126/njbs.v1i0.7481 Nepalese Journal of Biosciences 1: 140-147 (2011)

The effect of artificial diets on gonad colour and biomass in the edible sea urchin Psammechinus miliaris

During two 12 week trials, groups of edible sea urchins, Psammechinus miliaris, were fed artificial diets containing carotenoid pigments. The aim was to improve both the biomass and the colour of the sea urchin gonad in terms of its acceptability as a human food-stuff in the European market place. The pigmented artificial diets, based on the formula used by Robinson et al. (2002), increased gonad index (GI), pigment deposition and improved gonad colour from that of the initial samples. In Trial I gonad β-carotene levels increased > 2 fold, echinenone and total carotenoid > 7 fold. Trial II showed greater increases. Diets containing high levels of β-carotene (500 mg per kg dry weight of diet) gave rise to the highest percentages of marketable gonad colours (61–73%), and GI of 17.87–19.81%, (Trial I and II respectively). There was some variation in the results for this particular diet treatment across the two trials presumably reflecting individual urchins varying capacity to ingest, deposit or express the carotenoids in their diet. Providing additional lipids in the diets gave no improvement to gonad colour (56% acceptable) or GI (15.95%) suggesting the lipid content of the basic formulation is adequate. Utilizing an esterified form of lutein and zeaxanthin as a pigment source gave no significant improvement in gonad colour (30–63% acceptable) suggesting that this form of xanthophyll cannot be assimilated by P. miliaris. Female urchins had acceptable gonad colouration more often than males. The dominant carotenoid in the successful diets was β-carotene and this was successfully metabolized into echinenone, the dominant carotenoid in all gonad samples. Total levels of echinenone positively correlated with acceptable gonad colour scores. This study demonstrates that 12 weeks is sufficient to effect the desired change in gonad biomass and colour in cultivated P. miliaris.

Effects of fish hydrolysate (CPSP®) on growth and digestive gland lipid composition of Octopus vulgaris (Cuvier, 1797) juveniles

Effects of artificial diets were tested on growth and digestive gland (DG) lipid composition of juvenile Octopus vulgaris. For Experiment I, three diets were used: (i) SQUID (Loligo gahi) as a control diet; (ii) Squid paste and fish hydrolysate CPSP®, agglutinated with gelatine (GEL20); and (iii) Squid paste, fish hydrolysate CPSP® and gelatine (GEL40). For Experiment II, three diets were used: (i) SQUID, control diet; (ii) Squid paste, CPSP® and alginate (ALG10); and (iii) Squid paste, CPSP® and alginate (ALG20). For both experiments, growth rates for octopuses fed control were higher (P 0.05) between them. All diets promoted similar growth, regardless of the different CPSP® concentrations and binders. Growth rates obtained were among the highest obtained for O. vulgaris with artificial diets until now. The lower growth obtained with the artificial diets was greatly reflected in the DG fatty acid composition. The most important fatty acid groups, such as n-3 highly unsaturated fatty acids, decreased in the DG of animals fed artificial diets. Lipid content, particularly neutral lipids, was higher in the DG of octopuses fed squid, indicating higher nutritional condition of these animals compared to those fed the artificial diets.

Effect of Artificial Diets on Growth, Survival and Condition of Adult Cuttlefish, Sepia officinalis Linnaeus, 1758

The effects of artificial diets on growth and body condition of adult cuttlefish, Sepia officinalis were tested in two experiments. Supplemented prepared diets (fish myofibrillar protein concentrate) were fed during a 30-day and a 21-day experiments. Growth, feeding rate and food conversion of group-reared cuttlefish were analyzed. The first of these experiments tested four artificial diets, made with increasing levels of lysine, on adult cuttlefish. According to the chemical analysis, diets 1–3 had limiting concentrations of lysine and other essential amino acids (compared to mantle composition of the cuttlefish), while diet 4 was the only one where almost all essential amino acids were present in concentrations similar or higher than the ones present in cuttlefish mantle. A second experiment was conducted by isolating 16 adult cuttlefish individually, and feeding them the same four artificial diets, in order to obtain individual data. During Experiment 1, only the diet with the best chemical score (diet 4) produced growth (p < 0.05), with a mean instantaneous growth rate (MIGR) of 0.30% wet body weight (BW) d−1. Similarly, individually reared cuttlefish fed diet 4 produced the highest IGR’s (0.26, 0.38 and 0.48% BW d−1) and grew larger (p < 0.01). Comparison of cuttlefish fed the artificial diets vs. thawed shrimp and unfed cuttlefish indicated that cuttlefish fed the artificial diets were in an intermediate state. Growth rates obtained with the artificial diets (<0.4% BW d−1) were considerably lower compared to natural prey, live or frozen, reported by other authors.

Effect of Diet and Mating Status on Ovarian Development in a Predaceous Stink Bug &lt;I&gt;Perillus bioculatus&lt;/I&gt; (Hemiptera: Pentatomidae)

A method is presented to quantitatively score the degree of ovarian maturation in a predacious pentatomid with asynchronous follicle development. The effects of artificial diet and mating status on ovarian maturation rates were examined. Ovarian scores were not influenced by mating status but were significantly lower in females fed the artificial diet. Ovarian follicles start forming when females are 2.3 d old, reaching a peak at 4.5 d. In controls, the rate of new follicle formation decreases after the onset of vitellogenesis. By 4.5 d, all control ovarioles contained at least 1 vitellogenic follicle, and by 9.5 d all ovarioles had chorionated follicles. In contrast, females fed the artificial diet had 40% of the ovarioles with a vitellogenic and chorionated follicle at 10.5 d of age. Mating started when females were 3.5 d old and correlated with the start of vitellogenesis. Two peaks in mating were observed, one at 4.5 d and the other at 9.5 d. Regulatory mechanisms for oogenesis are discussed.

Prey‐mediated effects of Cry1Ab toxin and protoxin and Cry2A protoxin on the predator Chrysoperla carnea

AbstractLaboratory feeding experiments were carried out to study prey‐mediated effects of artificial diet containing Bacillus thuringiensis proteins on immature Chrysoperla carnea. Activated Cry1Ab toxin and the protoxins of Cry1Ab and Cry2A were mixed into standard meridic diet for Spodoptera littoralis (Boisduval) larvae at the following concentrations; for Cry1Ab toxin, 25, 50, 100 μg g−1 diet were used; for Cry1Ab protoxin, the concentration was doubled (50 μg g−1 diet, 100 μg g−1 diet and 200 μg g−1 diet) to give relative comparable levels of toxin concentration. Cry2A protoxin was incorporated into the meridic diet at one concentration only (100 μg g−1 diet). For the untreated control, the equivalent amount of double distilled water was added to the meridic diet. Individual C. carnea larvae were raised on S. littoralis larvae fed with one of the respective treated meridic diets described above. The objectives were to quantify and compare the resulting effects on mortality and development time of C. carnea with those observed in two previous studies investigating prey‐mediated effects of transgenic Cry1Ab toxin‐producing corn plants and the other studying effects of Cry1Ab toxin fed directly to C. carnea larvae. Mean total immature mortality for chrysopid larvae reared on B. thuringiensis‐fed prey was always significantly higher than in the control (26%). Total immature mortality of C. carnea reared on Cry1Ab toxin 100 μg g−1 diet‐fed prey was highest (78%) and declined with decreasing toxin concentration. Cry1Ab protoxin‐exposed C. carnea larvae did not exhibit a dose response. Prey‐mediated total mortality of Cry1Ab protoxin‐exposed chrysopid larvae was intermediate (46–62%) to Cry1Ab toxin exposed (55–78%) and Cry2A protoxin (47%) exposed C. carnea. In agreement with the previous studies, total development time of C. carnea was not consistently, significantly affected by the Bt‐treatments except at the highest Cry1Ab toxin concentration. However, both highest mortality and delayed development of immature C. carnea raised on Cry1Ab toxin 100 μg g−1 diet – fed prey may have been confounded with an increased intoxication of S. littoralis larvae that was observed at that concentration. At all other B. thuringiensis protein concentrations S. littoralis was not lethally affected. Comparative analysis of the results of this study with those of the two previous studies revealed that in addition to prey/herbivore by B. thuringiensis interactions, also prey/herbivore by plant interactions exist that contribute to the observed toxicity of B. thuringiensis– fed S. littoralis larvae for C. carnea. These findings demonstrate that tritrophic level studies are necessary to assess the long‐term compatibility of insecticidal plants with important natural enemies.

Artificial diets in sea urchin culture: effects of dietary protein level and other additives on egg quality, larval morphometries, and larval survival in the green sea urchin, Strongylocentrotus droebachiensis

The effect of artificial diets on the size and energy content of eggs and morphometry, survival, and metamorphic success of larvae was investigated in the green sea urchin, Strongylocentrotus droebachiensis, from the standpoint of developing a good broodstock diet for culturists. Groups of sea urchins were fed eight diets over a period of 9 months, then five of these dietary groups were selected for detailed larval-growth studies. The artificial diets differed in protein content and in various additives including mannitol, algin, cholesterol, and β-carotene; a diet of air-dried kelp was also included. Egg-energy content was highest on a high-protein diet with cholesterol and β-carotene additives, and the largest eggs so far recorded for the species (2.39 mm3 × 10−3) were produced on a high-protein diet with cholesterol additive. Larval survival to metamorphosis was &gt;92% for all diets save for kelp (&lt;5%). Kelp-fed adults also produced poorly metamorphosing larvae (&lt;2%), suggesting that air-drying causes chemical changes in the kelp that are ultimately detrimental to larval health. Larval developmental rates were fastest on the high-protein β-carotene formulation. Larvae from this diet group also had the longest arms relative to body length, largest rudiment diameter, largest absolute and relative ciliated-band length (for efficient feeding), and had a high percentage of metamorphosis. These data suggest that a high-protein β-carotene diet will be useful for conditioning broodstock by prospective sea urchin culturists.

The effects of artificial diets on fry production and growth of Oreochromis niloticus breeders

Tilapia breeders were fed with pelleted supplemental diets containing 20 or 40% crude protein at a daily feeding rate of 1% of fish biomass for 24 weeks in cages and tanks. Breeders were weighed and fry were collected at 3-week intervals. The 40% protein diet consistently gave the highest fry production and growth of breeders. The 20% protein diet gave variable results; fry production and growth were comparable to those of breeders fed with the 40% protein diet in some trials but significantly low in others. Breeders without supplemental feeding invariably had the least number of fry and the lowest body weights.

Effect of artificial diets on growth and survival of milkfish fry in fresh water

Wild milkfish fry (mean weight = 15 mg) were reared in fresh water for 5 weeks using four artificial dry diets, Moina, or blended water hyacinth leaves as feed. The fry fed with artificial diets attained 83–95% mean survival rates and 0.16–0.18 g mean weight gains. Those fed with Moina and blended water hyacinth leaves had much lower growth and survival. The four dry diets containing 40% crude protein appeared adequate for the fry. Substitution of up to 5% crude protein by soybean meal and/or ipil-ipil leaf meal did not affect growth, but diets containing ipil-ipil leaf meal gave slightly lower survival rates.

Studies on the nutrition of marine flatfish. The effect of dietary protein content on certain cell components and enzymes in the liver of Pleuronectes platessa

In order to examine the effects of artificial diets at the tissue level, plaice (Pleuronectes platessa L.) were fed either high (50%) or low (20%) protein diets for several weeks and the total quantities of deoxyribonucleic acid (DNA), ribonucleic acid (RNA), protein and phospholipid in their livers were measured. Alanine amino-transferase, aspartate aminotransferase, glutamate dehydrogenase and glucose-6-phosphatase activities in the livers were also measured. Similar measurements were made on the livers of wild plaice. The total amount of DNA in the livers of both cultured and wild plaice, of standard weight, did not differ significantly, irrespective of dietary history. In fish of standard weight, total hepatic RNA, protein and phospholipid levels were highest in the cultured fish fed high protein diet and lowest in the wild fish. These differences were related to dietary protein supply and environmental temperature. The total organ levels of the liver enzymes in plaice of equal weight were not significantly different in the cultured fish fed high and low protein diets. Wild-fish livers contained a smaller total amount of alanine aminotransferase, aspartate aminotransferase and glucose-6-phosphatase activity than did those of cultured fish. Total liver glutamate dehydrogenase activity was not significantly different in any of the fish examined. It is suggested that kinetic and allosteric factors may be more important in controlling protein metabolism and amino acid cat abolism in fish than total enzyme level.