Commercial Enrichment Research Articles

Fabrication and application of gold nanoparticles functionalized polymer monolith in spin column for the determination of S-nitrosoglutathione in meat

S-nitrosoglutathione (GSNO) is the most important S-nitrosothiol in vivo, which could affect the quality of meat by participating in calcium release, glucose metabolism, proteolysis and apoptosis, therefore may potentially serve as a marker for meat freshness. In this work, a solid-phase extraction (SPE) monolithic spin column modified with gold nanoparticles was prepared for GSNO extraction. The optimized SPE-LC-MS/MS method for GSNO quantification displays low limit of detection (0.01 nM), good precision (RSD < 15 %) and acceptable recovery (> 77.7 %). Furthermore, this approach has been applied to monitor GSNO levels in beef and pork stored at −20 °C for different days, showing that endogenous GSNO level increases during prolonged storage and could be employed as a marker to evaluate the freshness of ice stored meat. Additionally, the monolithic spin column remains in good quality after a half-year storage, which is promising to develop into commercial enrichment kit for endogenous GSNO analysis.

Structural Equation Modeling (SEM) of the interaction between cholecalciferol treatment and external factors in the incidence of vertebrae malformations in the hybrid grouper Epinephelus fuscoguttatus X Epinephelus polypehadion

Vitamin D3(VD3), also known as cholecalciferol plays a crucial role in maintaining calcium and phosphate homeostasis and has the potential to suppress bone malformations in fish larvae. However, external factors during growth also significantly influence the development of fish larval bones. Understanding the complex interaction between VD3 treatment and these external factors is crucial for optimizing therapeutic potential and effectively treating bone anomalies. SEM (Structural Equation Modeling) offers a comprehensive framework to explore these interactions by considering multiple variables simultaneously and examining their interrelationships. This study aimed to determine the impact of VD3 and its relationship with other external factors on the incidence of bone malformations in hybrid grouper larvae (Epinephelus fuscoguttatus X Epinephelus polyphekadion, EFEP). The treatments included a dose of 1.9 IU/g of VD3 in the feed and control group without VD3. All treatments received standard enrichment ingredients including vitamin C, taurine, and commercial enrichment (*SELCO). The enrichment was applied to rotifers (3 – 25 days after hatching, DAH) and artificial feed (25 – 35 DAH). The treatment was conducted in two batches, during the dry season (batch 1) and the rainy season (batch 2), to explore the seasonal impact on bone malformations. Results indicated that VD3 reduced the incidence of bone malformations in EFEP hybrid grouper fry by 1.14–1.65 times. SEM analysis revealed that spawning timing, egg quality, and water quality significantly impacted the occurrence of bone deformities, influencing malformations directly and indirectly through bone mineral content. This study demonstrated that bone malformations can be result from deficiencies in calcium, excess potassium and sulfur, and the presence of bromine in bone.

DHA-enrichment of live and compound feeds influences the incidence of cannibalism, digestive function, and growth in the neotropical catfish Pseudoplatystoma punctifer (Castelnau, 1855) during early life stages

Pseudoplatystoma punctifer is a highly appreciated fish species native to the Amazon basin, whose commercial farming has been hampered by low survival during early life stages due to the high incidence of cannibalism and the low acceptability of compound diets at weaning. Dietary DHA is known to promote digestive system development and maturation and growth, whereas its deficiency induces stress. The aim of this study was to evaluate the effect of dietary DHA supplementation on the incidence of cannibalism, digestive physiology, and growth performance during the early life stages of P. punctifer to improve current feeding protocols. Four dietary treatments were generated using a commercial enrichment product with high DHA content. Fish larvae were fed non-enriched or enriched Artemia from 4 to 15 days post fertilization (dpf) and fed a non-enriched or enriched compound diet from 15 to 26 dpf, coinciding with the start of the juvenile stage. Growth, survival, incidence of cannibalism, proximate and fatty acid composition, histology of the intestine and liver, and quantitative gene expression of the main digestive enzymes (amy, try, ctr, pga, pla2, and lpl) were analyzed in the different dietary groups at the end of each feeding period. Results showed that dietary DHA supplementation influenced P. punctifer in a developmental stage-dependent manner. In particular, DHA-enriched Artemia provided during the larval stage contributed to reduce the incidence of cannibalism and improved survival at the early juvenile stage, while enriching the compound diet improved growth. The expression level of genes involved in protein and carbohydrate digestion (ctr, amy) was higher in groups fed enriched Artemia despite that both enriched and non-enriched Artemia displayed similar proximate composition, suggesting that different dietary fatty acid profiles may modulate the expression of these digestive enzyme precursors. The group transitioning from enriched Artemia to non-enriched compound diet showed a higher expression of most genes at the early juvenile stage. At the histological level, the group fed non-enriched Artemia and compound diet showed a significant accumulation of lipids in the intestine relative to the liver, contrary to the rest of the groups that showed similar amounts of lipids in both tissues, indicating a more balanced lipid metabolism. The group fed both DHA-enriched Artemia and compound diet provided the best results in terms of growth, survival, incidence of cannibalism, and digestive physiology. In conclusion, this study showed that the nutritional history during the larval period affected fish nutrition and behavior during the early juvenile stage.

Improvement of the enrichment used in the EMJH medium (Ellinghausen–McCullough–Johnson–Harris) for the cultivation of Leptospira spp.

Changes were made to the original formulation of the EMJH medium (Ellinghausen–McCullough–Johnson–Harris) enrichment and some aspects such as growth time of Leptospira and utilization in the microscopic agglutination test (MAT) were evaluated and compared to the original enrichment and to a commercially available enrichment (DIFCO™). Leptospira samples (24 antigens) that make up our panel of antigens used in MAT were used, among them, reference and autochthonous strains isolated in Brazil. The samples were grown individually in the EMJH medium under the three previously mentioned conditions (adapted enrichment, original enrichment and commercial enrichment). In addition, 89 blood serums from domestic and wild animals were analyzed by MAT using the antigens grown in these media. All samples tested grew efficiently with the adapted enrichment, and the MAT results were satisfactory. Therefore, other laboratories could also benefit from the use of this adapted enrichment when culturing the Leptospira strains applied in their MAT panels.

Endophytes producing podophyllotoxin from Podophyllum sp. and other plants: A review on isolation, extraction and bottlenecks

Investigation on the secondary metabolites of endophytic organisms colonized within plant body is now giving emphasis on the medicinal properties of those products aiming to the finding of new drug molecules. Podophyllotoxin is a non-alkaloid lignan of plant origin found in some species of Podophyllum and several other genera such as Sinopodophyllum, Juniperus, Dysosma, Diphylleia, Linum, Lithospermum and so on. A few endophytic fungi which produce podophyllotoxin as secondary-metabolite are explored and reported in some available literatures. Isolation of specific endophytic fungal strains and their metabolite extraction can be done by using standard methods. Further research for the discovery of many other podophyllotoxin producing fungal endophytes and use of industrial fermentation technology may help in mass production. Survey of podophyllotoxin producing bacterial endophytic strains is also a prerequisite regarding commercial enrichment. It will certainly limit the overuse of the respective medicinal plant resources. Therefore, proper care must be taken and necessary policy may be formed by the appropriate authority to conserve these commercially valuable botanicals associated with endophytes. Informative knowledge about the wider distribution of endophytic microbes depending on the internal and external condition of the plant tissue may help to comprehend the role of those organisms in the production of bioactive metabolites.

Improvements on Live Feed Enrichments for Pikeperch (Sander lucioperca) Larval Culture.

Simple SummaryPikeperch (Sander lucioperca) is considered a species of high interest for the development of new species in the European Union. Currently, survival rates during the larval stages are below 20%. Inadequate larval rearing protocols, such as poor nutrition, are responsible for such low survival, which is stopping the commercial development of pikeperch. In order to improve and customize nutritional needs during the larval stages, the use of Chlorella vulgaris was introduced in the enrichment feeding protocol. The introduction of such algae to their diet through rotifers has improved survival and overall fitness by providing adequate fatty acids to their nutrition.This study focused on supplementing pikeperch (Sander lucioperca) larvae with rotifers fed with Chlorella vulgaris during the first 15 days post hatching (dph). Larvae were fed a combination of rotifers and artemia under three different enrichments: A) Nannochloropsis occulata, B) Chlorella vulgaris, and C) a commercial enrichment—Selco, Spresso from INVE. After 17 days from the trial initiation differences were found between treatments on survival rate, myomere height (MH), fatty acid composition, and stress tolerance. In terms of survival, larvae from treatment b (74.5%) and c (66%) excelled over the control (a) treatment (59%). Furthermore, larvae from both the Chlorella (b) and the Selco (c) treatments showed more resilience to stress conditions (10% and 37% reduction in mortality) when exposed to high salinity conditions (18ppt) for 3 h (stress response). Overall, larvae from treatments b and c performed better than those receiving a non-enriched diet (a), likely due to the higher levels of Essential Fatty Acids (EFA) and the ability of pikeperch to desaturate and elongate fatty acids (FA) with 18 carbons to LC PUFAs (Polyunsaturated Fatty Acids). The present study provides valuable input for designing improved feeding protocols, which will increase the efficiency of pikeperch larval culture.

Effects of a commercial broiler enrichment programme with or without natural light on behaviour and other welfare indicators

Commercial broiler production systems based on market initiatives to improve animal welfare beyond minimum legal requirements have emerged in several European countries. A common factor in the ‘higher welfare’ indoor systems is the application of environmental enrichment, with or without natural light, to promote locomotor activity and natural behaviours of the broiler chickens. In the current study, we evaluated the effects of a commercial enrichment programme for fast-growing indoor-housed broiler chickens, with or without natural light entering the broiler house. Enrichment materials were selected in relation to perceived minimal hygiene risk and ease of cleaning in between production cycles. Selected enrichments were a combination of wood shavings bales (1.5 bale/1000 chickens), round metal perches (2.7 m/1000 chickens) and metal chains as pecking objects (1/1000 chickens). Three treatments were studied: control (C) without enrichment and natural light, enriched (E) with enrichments as previously defined but without natural light and enriched plus natural light (EL) with enrichments as previously defined and natural light entrance. The experiment was carried out during five subsequent production cycles on one commercial broiler farm with three identical houses. EL could only be assigned to the middle house that was equipped with roof windows (light entrance area: 3% of floor space). C and E were in the two outer houses (alternated in between production cycles). Behaviour was observed during daytime at days 25 and 39 of age by scan sampling. Lameness, footpad dermatitis, hock burn, cleanliness and injuries were scored at the same ages, in addition to the response of the chickens to a novel object. Results showed that the treatments only affected broiler behaviour. E flocks showed significantly more resting as compared with EL and C. EL flocks showed significantly more walking, exploration and foraging behaviour as compared with E and C. Thus, broiler activity was highest in the EL treatment and lowest in the E treatment, with the C treatment in between. No treatment effects were found on the other welfare indicators and only a few tendencies for treatment effects were found for the novel object test, with E birds tending to be more reluctant to approach the object as compared with EL and C birds. We concluded that providing environmental enrichment and natural light-stimulated activity and natural behaviours in broiler chickens, whereas providing enrichment only seemed to have the opposite effect as compared with control flocks without enrichment.

A review of environmental enrichment for laying hens during rearing in relation to their behavioral and physiological development

ABSTRACTGlobally, laying hen production systems are a focus of concern for animal welfare. Recently, the impacts of rearing environments have attracted attention, particularly with the trend toward more complex production systems including aviaries, furnished cages, barn, and free-range. Enriching the rearing environments with physical, sensory, and stimulatory additions can optimize the bird's development but commercial-scale research is limited. In this review, “enrichment” is defined as anything additional added to the bird's environment including structurally complex rearing systems. The impacts of enrichments on visual development, neurobehavioral development, auditory stimulation, skeletal development, immune function, behavioral development of fear and pecking, and specifically pullets destined for free-range systems are summarized and areas for future research identified. Visual enrichment and auditory stimulation may enhance neural development but specific mechanisms of impact and suitable commercial enrichments still need elucidating. Enrichments that target left/right brain hemispheres/behavioral traits may prepare birds for specific types of adult housing environments (caged, indoor, outdoor). Similarly, structural enrichments are needed to optimize skeletal development depending on the adult layer system, but specific physiological processes resulting from different types of exercise are poorly understood. Stimulating appropriate pecking behavior from hatch is critical but producers will need to adapt to different flock preferences to provide enrichments that are utilized by each rearing group. Enrichments have potential to enhance immune function through the application of mild stressors that promote adaptability, and this same principle applies to free-range pullets destined for variable outdoor environments. Complex rearing systems may have multiple benefits, including reducing fear, that improve the transition to the layer facility. Overall, there is a need to commercially validate positive impacts of cost-effective enrichments on bird behavior and physiology.

Preliminary Findings on Supplementation of Snapper Fry, Lutjanus sp. with DHA-rich Thraustochytrid Strain, Schizochytrium sp. LEY7 Showed Increased Growth, Survival and Robustness

In this study, a preliminary experiment was conducted to investigate the beneficial effects of an indigenous DHA-rich thraustochytrid strain, Schizochytrium sp. LEY7 as supplement for snapper fry Lutjanus sp. using a long-term enrichment method (24 h) via Artemia. Results on the average total length (ATL) indicated that Schizohchytrium sp. LEY7 can be used as a growth enhancer (3.07 ± 0.03 mm) over the hatchery-produced emulsion (2.87 ± 0.04 mm) and the commercial enrichment SELCO (2.91 ± 0.04 mm). Starved treatment has an ATL of 2.89 ± 0.03 at the end of the feeding trial. Highest survival was obtained in the treatment fed Schizochytrium-enriched Artemia, with a mean survival of 65.52 ± 4.83, as compared to treatments fed Artemia enriched either with hatchery-produced emulsion (30.69 ± 25.17) or SELCO (54.14 ± 4.48). Survival of the starved treatment was 27.93 ± 10.69. There was a trend of lowest mortality seen for the treatment fed Schizochytrium-enriched Artemia when immersed at different salinity levels. Treatment fed SELCO-enriched Artemia was infested with the parasitic dinoflagellate Amyloodinium sp. Overall, the preliminary data obtained from this study indicate that the supplementation of Schizochytrium sp. LEY7 increases the quality of snapper fry and its chance of survival under adverse environmental conditions. Confirmatory experiments are therefore suggested to verify the results obtained.

DHA enrichment of the red earthworm Eisenia fetida for improving its potential as dietary source for aquaculture

This study aimed at assessing the potential of omega-3 fatty acids enrichment in the red earthworm Eisenia fetida. Specifically, the investigation focused on the effects of a commercial enrichment emulsion (ES) supplied at graded doses (0, 10, 25 and 50 g ES/100 g of compost) and at different enrichment times (0, 12, 24, 48 and 96 h) on the resulting fatty acids composition of red earthworm reared with or without additional bedding materials. In the first experiment (bed-free technique), inclusion of ES, in the highest tested dose (50 g/100 g compost), exerted stress on the earthworms resulting in high mortality, while the use of bedding in the second experiment led to safer but slightly reduced enrichment. Dominant fatty acids in earthworms were found to be PUFA (51.08–53.04 mol%), followed by MUFA (25.95–26.90 mol%) and SFA (21.16–22 mol%). Non-enriched earthworms contained some of the PUFA, important for cultured marine species, including 18:2n-6, 18:3n-3 and 20:5n-3 (EPA), whereas in contrast, 22:6n-3 (DHA) is very low. Overall the results of this study have, for the first time, showed that LC-PUFA, and especially DHA, contents of E. fetida can be enriched to levels much higher than those of the control (non-enriched) groups. In bed-free technique, DHA accumulation in the worms increased from 0.31 mol% (0 h) to 14.38–14.63 mol% at 12 h, 9.65–9.81 mol% at 24 h, 10.65–15.41 mol% at 48 h and finally 15.81–18.31 mol% at 96 h. In the bedding technique, DHA also rose from the base level to 5.27–5.97 mol% at 12 h, 5.25–8.60 mol% at 24 h, 11.06–13.01 mol% at 48 h and finally 14.05–17.14 mol% at 96 h. In the bedding technique, DHA increased linearly for up to 9.6 fold, while this increase was fluctuating in the bed-free technique, reaching 8.7 fold over the non-enriched controls. Throughout the experiments, n-3/n-6 ratios rose from 1.35–1.56 in the controls to 3.38–3.72 in the enriched-groups. As a result, 12-h enrichment time is suggested to be suitable for a fast boosting of DHA in the earthworms with bed-free technique, while a longer period of up to 96 h is recommended with bedding technique at optimal dose of 25 g ES inclusion into 100 g compost. The present study showed that earthworm (E.fetida) can be successfully enriched in its DHA content; making it a novel and easily producible feed resource, particularly as broodstock feed, in aquatic hatcheries.

The importance of copepods as live feed for larval rearing of the green mandarin fish Synchiropus splendidus

The green mandarin fish, Synchiropus splendidus, is a popular marine aquarium species, but currently sourced largely from the wild. To establish a reliable feeding regime for its larvae in captivity, a series of experiments were conducted. In the 1st experiment, newly hatched larvae were fed either unenriched rotifers (ss-type), rotifers enriched with Algamac 3000 or a mixture of commercial enrichments. An unfed control was also set up, which suffered a total mortality by 5 day post-hatching (DPH). All feeding treatments had similar low survival (<3.3%) by 11 DPH, suggesting rotifer enrichment bore little benefits. In the 2nd experiment, larvae were fed enriched and unenriched rotifers at 10 mL−1 and a mixed diet of 2 copepods (nauplii and copepodites of Parvocalanus crassirostris) + 8 rotifers mL−1. The copepods co-feeding with rotifers treatment showed dramatically improved survival (50%) as compared to rotifer feeding only treatments (≤5.6%) by 12 DPH (p < 0.01). The copepods + rotifers diet also generated significantly larger larvae (p < 0.01). The 3rd experiment aimed at determining the minimum quantity of copepods required for co-feeding with rotifers. Five treatments of copepods provided at 0, 0.1, 0.5, 1.0 and 2.0 mL−1 with rotifers making up the rest of a total of 10 prey mL−1 were set up. Larval survival to 11 DPH were significantly higher in the 2 copepods + 8 rotifers mL−1 and 1 copepods + 9 rotifers mL−1 treatments (52% and 48%) than other treatments (<19%) while no significant difference was detected between the two treatments. Larval growth was not significantly different among all copepod feeding treatments, even copepods were provided at only 0.1 mL−1, and they were all significantly higher than the rotifer feeding only treatment (p < 0.05). Our results demonstrated the importance of copepods as prey for rearing early larval S. splendidus and suggested that they should be co-fed at least 1.0 mL−1 to ensure good survival.

Salt as a decontamination agent to control bacterial load in Artemia salina cultures

Live food represents one of the major sources of bacterial contamination in larval culture. Since Artemia are widely used as live food, this approach has been thoroughly studied. Several techniques using antibiotics, ozone, chemical compounds, algae, and probiotics, have been tested to reduce bacterial load in Artemia. This research looked at the potential of salt to reduce bacterial contamination. Two salt treatments, consisting of 1 — a dip in a 200gL−1 salt solution, and 2 — a 24h enrichment in a 60gL−1 salt solution, were compared to a commercial antimicrobial enrichment product (A1 DHA Selco), a mix of commercial antibacterial products and a non-antimicrobial enrichment product (AlgaMac) as well as a control (enriched with AlgaMac). All treatments induced a reduction of the bacterial count of over 99.999983%. It was expected that different enrichment products would induce variations in the nutrient profiles, but the levels of DHA were higher in the Artemia treated with either of the salt treatments, when compared to the control. The salt treatment did not affect EPA and ARA levels, neither did it affect the levels of vitamins C and E. Therefore, salt allows for a comparable or higher reduction of the bacterial load in Artemia nauplii, than that obtained with other techniques, with a limited effect on nutrient profiles. Even more, the use of salt does not limit the choice of the enrichment product used, since it can be used in combination with a non-antibacterial enrichment product. Statement of relevanceUtilization of salt allows for a comparable or higher reduction of the bacterial load in Artemia nauplii than the ones obtained with more complicated or less durable techniques such as antibiotics, formaldehyde and ozone. As demonstrated in the present study, commercial enrichment products exist that allow for an achievement of similar results, but the use of salt does not limit the choice to enrichment products containing antimicrobial compounds, and produces minimal variations in the nutritional profiles of the Artemia. Therefore this new technique could be useful for all fish culture using Artemia.

Exome Capture with Heterologous Enrichment in Pig (Sus scrofa).

The discovery of new protein-coding DNA variants related to carcass traits is very important for the Italian pig industry, which requires heavy pigs with higher thickness of subcutaneous fat for Protected Designation of Origin (PDO) productions. Exome capture techniques offer the opportunity to focus on the regions of DNA potentially related to the gene and protein expression. In this research a human commercial target enrichment kit was used to evaluate its performances for pig exome capture and for the identification of DNA variants suitable for comparative analysis. Two pools of 30 pigs each, crosses of Italian Duroc X Large White (DU) and Commercial hybrid X Large White (HY), were used and NGS libraries were prepared with the SureSelectXT Target Enrichment System for Illumina Paired-End Sequencing Library (Agilent). A total of 140.2 M and 162.5 M of raw reads were generated for DU and HY, respectively. Average coverage of all the exonic regions for Sus scrofa (ENSEMBL Sus_scrofa.Sscrofa10.2.73.gtf) was 89.33X for DU and 97.56X for HY; and 35% of aligned bases uniquely mapped to off-target regions. Comparison of sequencing data with the Sscrofa10.2 reference genome, after applying hard filtering criteria, revealed a total of 232,530 single nucleotide variants (SNVs) of which 20.6% mapped in exonic regions and 49.5% within intronic regions. The comparison of allele frequencies of 213 randomly selected SNVs from exome sequencing and the same SNVs analyzed with a Sequenom MassARRAY® system confirms that this “human-on-pig” approach offers new potentiality for the identification of DNA variants in protein-coding genes.

Effect of zooplankton as diet for the early paralarvae of Patagonian red octopus,Enteroctopus megalocyathus, grown under controlled environment

The limited success reported in the paralarval culture of merobenthic octopus is mainly attributed to nutritional problems. This study aimed to determine the effect of live diets on the paralarvae performance during the first 30 days after hatching (DAH). The paralarvae were grown under different treatments: starved (STV) as negative control or fed four diets: Artemia sp. enriched with microalgae (ANCH), Artemia enriched with a commercial enrichment (AOG), Artemia enriched with microalga + commercial enrichment (AMIX) and king crab zoea (ZKC). The paralarval growth and survival were affected by the dietary treatment, with significant higher growth in ANCH and AMIX. STV showed 100% mortality at day 27, whereas all diets resulted within a range from 20% to 33% survival. The endogenous protein and lipid reserves were utilized in all treatments. The 22:6n-3/20:5n-3 ratio increased up to 16% during the experimental period. Alkaline protease activity tended to increase in paralarvae fed ANCH, AOG and ZKC over the first 13 DAH; however, this effect was not observed in trypsin nor chymotrypsin activities. The leucine aminopeptidase activity (LAP) was not affected by the dietary treatment, while alkaline phosphatases increased only at 13 DAH in paralarvae fed ANCH. Indicators of the nutritional status of paralarvae are discussed.

Growth of healthy and sanitizer-injured Salmonella cells on mung bean sprouts in different commercial enrichment broths

The ability of nine commercial broths to enrich healthy and 90% sanitizer-injured Salmonella Typhimurium and Salmonella cocktail on mung bean sprouts was evaluated to select an optimum broth for detection. Results showed that S. Typhimurium multiplied faster and reached a higher population in buffered peptone water (BPW), Salmonella AD media (AD) and ONE broth-Salmonella (OB), compared with other broths. Healthy and 90% sanitizer-injured Salmonella at low concentrations increased by 4.0 log CFU/ml in these three broths. However, no Salmonella growth was observed in lactose broth (LB). Further investigation showed that during incubation, pH of LB dropped from 6.7 to 4.2, due to production of lactic (66 mM) and acetic acids (62 mM) by lactic acid bacteria that were identified as dominant microbiota in bean sprouts. Though no cell membrane damage was detected by propidium monoazide combined with real-time PCR, it was found that LB inhibited Salmonella growth, especially from low inoculum levels. This study suggests that in consideration of effectiveness and cost, BPW would be a suitable enrichment broth to use for isolating and detecting Salmonella on mung bean sprouts, while using LB might cause false negative results in Salmonella detection by either PCR or standard cultural method.

Effects of feeding with frozen freshwater cladoceran Moina macrocopa on the performance of red sea bream Pagrus major larviculture

The feeding effects of freshwater cladoceran Moina macrocopa to the larvae and juveniles of red sea bream were investigated. M. macrocopa was mass-cultured with freshwater Chlorella as feed and was enriched nutritionally with a commercial enrichment diet. Because M. macrocopa die in seawater within a few minutes, the cladocerans were frozen after nutritional enrichment. The survival rates, growth rates and stress tolerances of fish fed with enriched M. macrocopa were compared with those fed with enriched Artemia and with zooplankton harvested from open seawater. The fatty acid composition of each type of zooplankton was analyzed. Mass-cultured M. macrocopa could be enriched with a commercial enrichment diet. The DHA/EPA ratio of M. macrocopa was inferior to that of enriched Artemia nauplii and wild zooplankton. Although the growth and stress tolerance of fish fed on frozen M. macrocopa were inferior to those fed with enriched Artemia nauplii and wild zooplankton, their survival rate was superior. It was concluded that frozen and enriched M. macrocopa could be fed to red sea bream larvae and juveniles. However, it is necessary to improve its fatty acid composition, particularly the DHA content.

Growth of flounder larvae, Paralichthys olivaceus using enriched rotifer fed with artificial microparticle diets

Three types of artificial microparticle diets were developed for rotifer (Brachionus plicatilis) enrichment. The efficacies of enrichment with the artificial diets were evaluated and compared to those with commercial enrichment diets on the growth and survival of flounder larvae. Total lipid content was highest in the rotifer enriched with oil capsule (40.5% in dry weight). The n-3 highly unsaturated fatty acid (n-3 HUFA) content was also highest in the rotifer fed with oil capsule (7.08% in dry weight). The flounder larvae fed on the rotifer enriched with oil capsule showed the highest growth compared to those fed on any other enriched rotifer (P<0.05). The survival ratio of flounder larvae fed on the rotifers enriched with oil capsule and emulsion oil were higher than those fed on any other enriched rotifer (P<0.05). From the feeding study, the growth and survival of flounder larvae were enhanced by feeding rotifer enriched with oil capsule compared to rotifer enriched with any other diets. The rotifer fed on oil capsule containing high contents of n-3 HUFA. Therefore, a significant relationship between the growth and survival of flounder larvae and the n-3 HUFA content of rotifer could be obtained.

Rotifers enriched with iodine, copper and manganese had no effect on larval cod (Gadus morhua) growth, mineral status or redox system gene mRNA levels

It currently remains unclear if rotifers contain sufficient mineral levels to meet larval fish requirements. In this study, rotifers were enriched with a commercial enrichment (control), or with additional iodine, iodine and copper, or iodine, copper and manganese, and the effects of feeding these rotifers to Atlantic cod (Gadus morhua) larvae from 3 to 18 days post hatch were investigated. Rotifer enrichment with minerals was successful, but Mn enrichment also increased rotifer zinc levels. No differences were observed between treatments in larval growth or survival, or in the mRNA levels in the majority of the redox system genes analysed. Only Zn levels increased in cod larvae in response to mineral enrichment of rotifers. Apart from Zn, little evidence was found to suggest that cod larvae require increased concentrations above the control rotifer levels of the essential elements studied here.

LIFE-FEED ENRICHMENT FOR LARVAL REARING OF YELLOWBAND CLOWNFISH (Premnas biaculeatus)

The seeds of yellowband clownfish from hatchery has a pale skin colour and a yellow stripe became white colour. The purposes of this research were to know the effects of life-feed enrichment on the growth of larva and the appearance of colors yellowband clownfish. The treatments were the enrichment of rotifers and Artemia with commercial enrichment + Nannochloropsis (A), and without commercial enrichment as control, only Nannochloropsis (B). This research conducted for 15 days rearing. Larva rearings of yellowband clownfish fish with treatment A were resulted the total length at the end experiment was 7.72 ± 0.63 mm, dan survival rate 52.6 ± 19.1 %. The total length at treatment B was 7. 61 ± 0.43 mm and survival rate 47.7 ± 24.2%. Different enrichment of life-feed was not significant different effect for total length, survival rate and colour of seeds Keywords: life-feed, enrichment, growth, survival rate, colour, yellowband clownfish.

LIFE-FEED ENRICHMENT FOR LARVAL REARING OF YELLOWBAND CLOWNFISH (Premnas biaculeatus)

&lt;p&gt;The seeds of yellowband clownfish from hatchery has a pale skin colour and a yellow stripe became white colour. The purposes of this research were to know the effects of life-feed enrichment on the growth of larva and the appearance of colors yellowband clownfish. The treatments were the enrichment of rotifers and Artemia with commercial enrichment + Nannochloropsis (A), and without commercial enrichment as control, only Nannochloropsis (B). This research conducted for 15 days rearing. Larva rearings of yellowband clownfish fish with treatment A were resulted the total length at the end experiment was 7.72 ± 0.63 mm, dan survival rate 52.6 ± 19.1 %. The total length at treatment B was 7. 61 ± 0.43 mm and survival rate 47.7 ± 24.2%. Different enrichment of life-feed was not significant different effect for total length, survival rate and colour of seeds&lt;/p&gt; &lt;p&gt;Keywords: life-feed, enrichment, growth, survival rate, colour, yellowband clownfish.&lt;/p&gt;