Algae Supplementation Research Articles

Rumen methane abatement by phlorotannin derivatives (phlorofucofuroeckol-A, dieckol, and 8,8′-bieckol) and its relationship with the hydroxyl group and ether linkage

Brown algae supplementation is one method for lowering rumen CH4 production because of the ability of the brown algae's phlorotannins to mitigate enteric CH4 emissions. The objective of this study was to evaluate the effects of phlorotannin derivatives, phlorofucofuroeckol-A (PFFA), dieckol (DE), and 8,8′-bieckol (BE), on rumen in vitro CH4 emissions and to investigate the relationship between the number of their hydroxyl groups or ether linkages with CH4 reduction rate of phlorotannin derivatives. Rumen fluid obtained from two cannulated Holstein cows were incubated in an in vitro batch culture system for 24 and 48 h. Each phlorotannin derivative was added to the substrate at the five different concentrations of 0, 2, 4, 8, and 16 g/kg on a dry matter basis. Methane emission was decreased by 16 g/kg PFFA (linear, P < .01; quadratic, P = 0.06) and DE (linear, P < .01) supplementation and by 8 g/kg BE (linear, P < .01; quadratic, P = 0.05) addition at 24 h of incubation. There were no differences in rumen CH4 production at 48 h of fermentation. Total gas production was decreased at 24 h of incubation by PFFA (linear, P < .01; quadratic, P < .01), DE (linear, P < .01), and BE (linear, P < .01; quadratic, P = 0.02). The model for total gas production and CH4 emissions upon PFFA (r2 = 0.69, P < .01, and r2 = 0.65, P < .01, respectively) and BE supplementation (r2 = 0.42, P = 0.04, and r2 = 0.71, P < .01, respectively) showed a quadratic correlation. The CH4 abatement rate was positively correlated with the number of hydroxyl groups and ether linkages of phlorotannin derivatives (r2 = 0.46, P < .01, and r2 = 0.32, P < .01, respectively). In conclusion, the three pure and individual phlorotannin derivatives (PFFA, DE, and BE) in brown algae are candidates for rumen CH4 abatement, and their CH4 mitigating effects could depend on the number of the hydroxyl groups and ether linkages.

Radioactive isotopes 40K, 137Cs, 226Ra, 228Ra, 234Th in algae supplements – Potential radiotoxicity of aquatic superfoods

Many food products are recommended to give health benefits. Thus algae superfoods consumption is growing worldwide, although quite a few studies have examined the quantities of radionuclides they contain and their potential effects on human health. The study presents radioactive 40K, 137Cs, 226Ra, 228Ra, and 234Th in algae supplements available worldwide for human consumption. Samples have been quantified by gamma-ray spectrometry and the activity concentrations (Bq/kg dw) ranged 0.23–0.65 (137Cs) followed by 1.76–10.7 (226Ra), 0.20–12.7 (228Ra), 11.6–24.2 (234Th), and 20.1–400 (40K). Also, the effective radiation doses from 40K, 137Cs, 226Ra, 228Ra, and 234Th decay ingested with analyzed algae supplements have been estimated. The highest annual effective dose reaching 15.1 µSv/year has been assessed for naturally occurring 226Ra in Chlorella vulgaris from Japan. The Fukushima Nuclear Power Plant has not significantly impacted the effective dose from 137Cs present in algal superfoods. Based on the study, the activity concentrations of radionuclides seem to be low, the naturally occurring radionuclides would give the highest effective doses, and the investigated algae supplements could be considered safe food.

Review of Associated Health Benefits of Algal Supplementation in Cattle with Reference to Bovine Respiratory Disease Complex in Feedlot Systems.

Simple SummaryBovine Respiratory Disease is considered one of the most common diseases within the Australian beef industry. Research into the use of algal supplementation is increasing due to the positive health benefits associated with the bioactive compounds within the algae. Studies have found benefits such improving the animal’s immune response to the disease and overall health. Further research is required to fully investigate these results.Within the Australian beef industry bovine respiratory disease is considered one of the most common disease and costs the industry an average net loss of $1647.53 Australian dollars per animal death to bovine respiratory disease complex (BRD). This is due to the disease overwhelming the animal’s immune system during a period where they experience multiple stressors that consequently increase the animal’s susceptivity to disease. Research into the bioactive compounds commonly found in marine algae is rapidly increasing due to its positive health benefits and potential immune modulating properties. Algal supplementation within previous studies has resulted in improved reproduction potential, growth performance, increases antioxidant activity and decreased proinflammatory cytokine concentrations. Additional research is required to further understand the aetiology of BRD and complete analysis of the bioavailability of these bioactive compounds within marine algae to fully explore the potential of marine algae supplementation.

Influence of Dietary Algae Meal on Lipid Oxidation and Volatile Profile of Meat from Lambs with Competent Reticular Groove Reflex.

Dietary lipid sources influence intramuscular fatty acid composition, which in turn may affect the volatile profile of meat. The aim of this work was to investigate the effects of marine algae supplementation (Aurantiochytrium limacinum) on volatile compounds of cooked lamb meat. Forty-eight lambs with 42 days of age were divided into three groups: lambs fed a conventional diet without algae meal supplementation (NOALG), lambs with competent reticular groove reflex (RGR) fed the same diet supplemented with 2.5% marine algae meal mixed in the concentrate (ALGCON), and lambs with competent RGR, receiving the same diet and fed with 2.5% marine algae meal in a milk replacer to bypass the rumen (ALGMILK). Lipid and protein oxidation in raw meat was assessed and volatile compounds in grilled meat were determined. The highest and lowest lipid oxidations were observed in the ALGMILK and NOALG groups, respectively. Protein oxidation was unaffected. Out of 56 identified compounds, 12 volatiles significantly increased in both algae groups and 6 of them exclusively in the ALGCON treatment. Algae meal supplementation and its form of administration, either protected or not from rumen degradation, are important factors to consider in lipid oxidation and the aromatic profile of lamb meat.

Growth performance and physiological status evaluation of Spirulina platensis algae supplementation in broiler chicken diet

Spirulina platensis algae (SPA) is a natural feed supplement with 40 to 45% crude protein, 2.44% Ca, and 6.27% P. It contains substances (e.g., β-carotene and zeaxanthin, and high Fe, vitamins and phycocyanin). These substances reveal potential biological properties such as antioxidative, anti-inflammatory, and hypolipidemic contain. The effects of dietary supplementation of SPA on growth performance, antioxidative, immune status, and intestinal histology were investigated. A total of 540 broiler chickens were randomly assigned into 3 treatments of 18 breeding pens each housed in 6 replicates per each experimental treatment (30 broiler chickens per pen). Three diets were formulated to contain 0, 3, and 6% of SPA and fed from d 7 to 35. Body weight and body weight gain at 5 wk of age were greater in the diet containing 6% SPA compared with the 0% SPA. The supplementation of SPA to a broiler chicken diet improved the feed conversion ratio. The obtained results of the experiment showed that broiler chicken fed with 3 and 6% of feed SPA increased RBC, Hb, and WBC and lymphocyte was greater (P ≤ 0.05) values compared to the 0% SPA. Serum total lipid, cholesterol, and triglyceride concentrations in the diet containing 3 or 6% SPA decreased compared with the 0% SPA. Furthermore, the concentration of high-density lipoprotein was increased , while the opposite is observed with low-density lipoprotein concentration. Serum Ca and P concentrations had greater in the diet containing 3 or 6% SPA compared to the 0% SPA. Both the 3 and 6% SPA groups increased (P ≤ 0.05) blood glutathione; however, the SPA groups decreased (P ≤ 0.05) malondialdehyde but increased blood immunity status relative to the control group. Moreover, the content of Ca and P in tibia ash increased in both broiler chicken fed the diets containing 3 and 6% SPA compared with those fed the diet containing 0% SPA. In comparison to the control treatment, all experimental chickens had increased villus height, goblet cells per 100 enterocytes and villus height per crypt depth in the jejunum histology examination. The inclusion of SPA in broiler chicken fed the diet containing of 6% had a considerably positive effect on growth performance and gut health status. In addition, it is a good source of Ca and P to increase tibia strength.

Algae Supplementation for Exercise Performance: Current Perspectives and Future Directions for Spirulina and Chlorella.

Nutritional clinical trials have reported algae such as spirulina and chlorella to have the capability to improve cardiovascular risk factors, anemia, immune function, and arterial stiffness. With positive results being reported in clinical trials, researchers are investigating the potential for algae as an ergogenic aid for athletes. Initial studies found spirulina and chlorella supplementation to increase peak oxygen uptake and time to exhaustion, with the mechanistic focus on the antioxidant capabilities of both algae. However, a number of oxidative stress biomarkers reported in these studies are now considered to lack robustness and have consequently provided equivocal results. Considering the nutrient complexity and density of these commonly found edible algae, there is a need for research to widen the scope of investigation. Most recently algae supplementation has demonstrated ergogenic potential during submaximal and repeated sprint cycling, yet a confirmed primary mechanism behind these improvements is still unclear. In this paper we discuss current algae supplementation studies and purported effects on performance, critically examine the antioxidant and ergogenic differing perspectives, and outline future directions.

Docosahexaenoic acid-rich algae oil supplementation on breast milk fatty acid profile of mothers who delivered prematurely: a randomized clinical trial

Preterm infants are deficient in long-chain polyunsaturated fatty acids, especially docosahexaenoic acid (DHA), a fatty acid (FA) associated with an increase in bronchopulmonary dysplasia (BPD). In two previous randomized control trials, DHA supplementation did not reduce the risk of BPD. We examined the breast milk FA profile, collected 14 days after birth, of mothers who delivered before 29 weeks of gestation and who were supplemented with DHA-rich algae oil or a placebo within 72 h after birth as part of the MOBYDIck trial. Milk FA were analyzed by gas chromatography. The total amount of FA (mg/mL) was similar in both groups but the supplementation increased DHA (expressed as % of total FA, mean ± SD, treatment vs placebo, 0.95 ± 0.44% vs 0.34 ± 0.20%; P < 0.0001), n-6 docosapentaenoic acid (DPA) (0.275 ± 0.14% vs 0.04 ± 0.04%; P < 0.0001) and eicosapentaenoic acid (0.08 ± 0.08% vs 0.07 ± 0.07%; P < 0.0001) while decreasing n-3 DPA (0.16 ± 0.05% vs 0.17 ± 0.06%; P < 0.05). Supplementation changed the ratio of DHA to arachidonic acid (1.76 ± 1.55% vs 0.60 ± 0.31%; P < 0.0001) and n-6 to n-3 FA (0.21 ± 0.06% vs 0.17 ± 0.04%; P < 0.0001). DHA-rich algae supplementation successfully increased the DHA content of breast milk but also included secondary changes that are closely involved with inflammation and may contribute to changing clinical outcomes.

Algal supplements in formulated feeds: Effects on sea urchin gonad quality

In the effort to increase the commercial value of urchin gonads produced via roe enhancement aquaculture, a variety of formulated feeds have been tested to increase gonad production and improve colour and taste. The addition of dried algal supplements to formulated feeds can further enhance gonad quality, but the level of improvement is highly variable and algae or urchin species dependent. Here we test whether the inclusion of three types of dried algal supplements (Sargassum fallax, Ecklonia radiata, and Durvillea potatorum) added to a pellet-based formulated aquaculture feed could further enhance the colour, taste and gonad quality in the temperate urchin Heliocidaris erythrogramma during two 12 wk. gonad enhancement periods, April to June, and July to September. All feed types resulted in urchins with gonad indices (GIs) of commercially acceptable quantities (Apr-Jun: GI = 14.6%, Jul-Sep: GI = 14.9%). The proportion of marketable gonads (A + B grades) was significantly higher during the Jul-Sep (87.9 ± 3%, mean ± SE) compared to the Apr-Jun (76.6 ± 3%, mean ± SE) enhancement period, however, algal supplement type did not improve gonad colour, taste, or the proportion of marketable gonads when compared to the control feed. We conclude that additional algal supplements may fail to further improve roe quality if the base formulated feed used to roe enhance is already of a standard that produces a sufficient proportion (>70%) of marketable roe.

Supplementation of macro algae (Azolla pinnata) in a finishing ration alters feed efficiency, blood parameters, carcass traits and meat sensory properties in lambs

The effects of dietary supplementation with Azolla pinnata (a macro algae) on lamb performance, blood parameters, carcass traits and meat quality were investigated. Thirty fat-tail uncastrated male Moghani lambs with an initial average body weight (BW) of 28 ± 1.4 kg were allocated to one of three dietary treatments (10 lambs/treatment) by stratified randomisation based on BW. Lambs were fed ad libitum for 90 d with a standard finishing diet containing sun-dried Azolla at 0, 10 and 20 % (DM basis) levels. Results showed that the feed intake tended to be lower (P = 0.074) in Azolla supplemented lambs, the values were 1.73 and 1.69 and 1.48 kg DM/d, for 0, 10 and 20 % Azolla, respectively. Plasma urea and creatinine concentrations were lower in Azolla supplemented lambs than control group (P < 0.05). BW was not affected by dietary supplementation of Azolla (P> 0.05) but inclusion of Azolla in the feedlot ration improved (P = 0.004) feed conversion ratio. Hot and cold carcass weights were greater (P = 0.009) for lambs fed with 10 % Azolla (24.9 and 24.4 kg), than for the control group (22.5 and 22.1 kg, respectively). Other carcass traits and longissimus muscle chemical composition were not impacted by Azolla supplementation (P > 0.05). Lambs that were supplemented with 20 % Azolla in the feedlot ration had greater odor intensity scores (P = 0.01) compared with the control group. The sensory properties of meat were not altered by 10 % Azolla diet. Azolla supplementation at 10 % and 20 % had no effect on meat quality attributes (P > 0.05). From these results, the supplementation of Azolla pinnata at 10 % level is recommended as a feed source to improve feed conversion ratio and carcass weights for Moghani lambs, without compromising meat quality and sensory properties.

Enhancement of immune response and resistance to Vibrio parahaemolyticus in Tilapia fish (Oreochromis mossambicus) by dietary supplementation of Portieria hornemannii

Supplementation of red algae can act as potent immune stimulator and have the effectiveness to induce immune related genes which play an important role in host defense mechanism. The objective of the present study is to scrutinize the potentiality of Portieria hornemannii (pH) extract to improve the disease resistance and immune response in Tilapia (Oreochromis mossambicus). Fishes were fed with PH diet for 45 days prior to the experimental challenge with Vibrio parahaemolyticus. Expression of immune related genes and immune parameters were analyzed at 1, 7 and 14 day of post challenge period. Fishes fed with PH diet showed higher percentage of survival when compared to the control group 14 day post challenge. Significant increase in antiprotease, serum lysozyme and NBT activity were seen in tilapia fed with PH extract diet (15 mg/g). These results simplified that PH extract can elevate the survival rate restraining the immune response in O.mossambicus.

Seaweed Supplementation Failed to Affect Fecal Microbiota and Metabolome as Well as Fecal IgA and Apparent Nutrient Digestibility in Adult Dogs

Simple SummarySeaweeds represent a source of bioactive compounds that have recently drawn the attention of the scientific community for their possible application as health-promoting ingredients. In particular, their indigestible polysaccharides have exhibited promising prebiotic properties both in humans and in farm animals. The present study investigated for the first time in healthy adult dogs the effects of dietary supplementations with intact seaweeds (brown algae Ascophyllum nodosum, Undaria pinnatifida, Saccharina japonica and red alga Palmaria palmata) on some fecal bacterial populations and metabolites, fecal IgA and apparent total tract digestibility of nutrients. The different algal supplementations (fed to ten healthy adult dogs at a dietary dose of 15 g/kg for 28 days) did not have any significant effect on the selected fecal microbial parameters, intestinal immunity and nutrient digestibility. Further studies investigating higher dietary inclusions of intact seaweeds or their polysaccharide extracts are needed to gain a better understanding of the potential of these interesting marine resources in companion animal nutrition.The present study investigated in dogs the dietary effects of intact seaweeds on some fecal bacterial populations and metabolites, fecal IgA and apparent total tract digestibility (ATTD). Ten healthy adult dogs were enrolled in a 5 × 5 replicated Latin square design to evaluate five dietary treatments: control diet (CD); CD + Ascophyllum nodosum; CD + Undaria pinnatifida; CD + Saccharina japonica; CD + Palmaria palmata (n replicates per treatment = 10). Seaweeds were added to food at a daily dose of 15 g/kg. The CD contained silica as a digestion marker. Each feeding period lasted 28 d, with a 7 d wash-out in between. Feces were collected at days 21 and 28 of each period for chemical and microbiological analyses. Fecal samples were collected during the last five days of each period for ATTD assessment. Dogs showed good health conditions throughout the study. The fecal chemical parameters, fecal IgA and nutrient ATTD were not influenced by algal supplementation. Similarly, microbiological analyses did not reveal any effect by seaweed ingestion. In conclusion, algal supplementation at a dose of 15 g/kg of diet failed to exert noticeable effects on the canine fecal parameters evaluated in the present study.

Influence of Algae Supplementation on the Concentration of Glutathione and the Activity of Glutathione Enzymes in the Mice Liver and Kidney.

Algae are potential and natural source of long-chain polyunsaturated fatty acids like eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The diatom Pinnularia borealis accumulates high levels of EPA and may be considered as a source for commercial production of dietary supplements. In this study we asked the question whether diet supplementation with P. borealis may augment antioxidant defense and ameliorate risk factors for cardiovascular diseases. We fed mice (Mus musculus) with lyophilized diatom solutions of different concentrations (1%, 3%, and 5%) for 7 days. Then we measured glutathione content and the activity of glutathione redox system enzymes, total cholesterol and triacylglycerol concentrations, and malondialdehyde concentration in the liver and kidney. We found that cholesterol and triacylglycerol concentrations in the liver and kidneys were the lowest in mice who were fed with the highest concentration of Pinnularia borealis, suggesting protective properties of algae. Additionally, the lowest concentration of Pinnularia borealis was sufficient to improve antioxidant capacity. Our results suggest that P. borealis may be used as a source for dietary supplements rich in EPA, but the amount supplied to the organism should be limited.

Effects of Algae Meal Supplementation in Feedlot Lambs with Competent Reticular Groove Reflex on Growth Performance, Carcass Traits and Meat Characteristics.

There is growing interest in increasing omega-3 fatty acid (FA) contents in ruminant meat by means of dietary manipulation, but the effects of such manipulation on productive results and meat quality need to be ascertained. The aim of the present study was to assess the effects of supplementing lambs with competent reticular groove reflex (RGR) with marine algae as a source of omega-3 fatty acids on growth performance, carcass traits, and meat quality characteristics. Forty-eight feedlot lambs were distributed into three equal groups: the control group neither consumed marine algae nor had competent RGR, the second group received daily 2.5% of algae meal mixed in the concentrate, and the last group consumed the same amount of algae meal, but emulsified in a milk replacer and bottle-fed. Lambs in the second and third groups had competent RGR. There were not any negative effects on performance, carcass or meat quality parameters with algae supplementation. However, the results of the oxidative stability parameters were not conclusive. Ageing for 6 days improved meat tenderness and color, and increased lipid oxidation. In conclusion, algae meal inclusion in the diet of fattening lambs with competent RGR has no detrimental effects on animal performance, carcass traits or meat quality characteristics.

Effect of Marine Algae Supplementation on Somatic Cell Count, Prevalence of Udder Pathogens, and Fatty Acid Profile of Dairy Goats’ Milk

Simple SummaryNowadays, there has been increased interest in the modification of the fatty acid composition of foods, such as milk and milk products, to reduce human health problems. The most common way to improve the composition of foodstuffs by n-3 polyunsaturated fatty acids (PUFA) is supplementing animal diets with different plant oils, seeds, fish oil, and freshwater and marine algae. Moreover, fish oil and marine algae (e.g., Schizochytrium limacinum) supplements are a good source of long-chain PUFA (LC-PUFA), such as docosahexaenoic acid (DHA). DHA is essential for the development and normal function of the brain, and DHA has beneficial effects for human health, such as reducing the risk of coronary heart disease. In addition, DHA fatty acid has an anti-inflammatory effect, which may help to improve the health of mammary gland secretory activity against the mastitis pathogens. Mastitis pathogen bacterial infection causes an inflammatory reaction within the udder and it leads to reduced milk secretory activity and produces a disadvantageous quality of milk. It was found that marine algae supplementation improved the concentrations of beneficial fatty acids of milk, including higher concentrations of DHA and rumenic fatty acids. In addition, marine algae supplementation decreased the somatic cell counts and prevalence of mastitis pathogens in milk.The aim of this study was to evaluate the effect of the Schizochytrium limacinum marine algae on the milk composition and fatty acid profile, somatic cell count, and prevalence of pathogen bacteria in the raw milk of multiparous Alpine goats. Twenty-eight dairy goats were randomly allocated to two groups: control group (C)—fed with 1500 g alfalfa hay and 600 g concentrate; experimental group (MA)—received the same forages and concentrate supplemented with 10 g/head/day marine algae. The goats were housed indoors, while the experiment lasted five weeks, and the milk samples were taken every week. Marine algae feeding had no negative effect on milk composition. The marine algae inclusion significantly decreased the milk somatic cell count and the presence of udder pathogens in the MA group. Mean somatic cell count and presence of udder pathogens were 5.73 log cells/mL and 31%, respectively, in the C group, while these values were 5.34 log cells/mL and 10%, respectively, in the MA group. The marine algae supplementation significantly increased DHA and rumenic acid concentration in the milk of the MA group (0.32 and 0.99 g/100 g of fatty acids, respectively) compared to the C group (0.04 and 0.65 g/100 g of fatty acids, respectively). It can be concluded that a diet supplemented with marine algae significantly improves the udder health of goats and the concentrations of health-promoting fatty acids in milk.

The balancing act: Protein, lipid and seaweed dietary levels to maximize gonad quantity in a wild‐caught sea urchin

Sea urchin gonads (roe) are a prized global sea food commodity, with growing demand driving the need for urchin roe enhancement aquaculture. Effective roe enhancement of urchins using formulated feeds require species‐specific optimization and an understanding of the interactions between key dietary components (e.g. protein, lipid, carbohydrate, energy and/or algal supplements). Here, we tested 18 formulated feeds on the sea urchin Heliocidaris erythrogramma, collected from barrens. The 18 iso‐energetic (~20 MJ/kg) feed combinations contained one of three protein levels (250, 375 or 500 g/kg), three lipid levels (73, 101 or 131 g/kg) combined with a single (45 g/kg Sargassum spp.) or multiple (45 g/kg Sargassum spp., 25 g/kg Solieria robusta, 25 g/kg Ulva lactuca) dried algal supplement. From two consecutive 12‐week enhancement trials, the most optimal feed type contained 375 g/kg protein, 73 g/kg lipid and a 45 g/kg algal supplement (Sargassum spp.) and produced gonad indices of 18.5 ± 0.4% (Trial 1) and 21.7 ± 1.2% (Trial 2). Across feed types, there was no significant difference in the proportion of marketable quality (A and B grade) roe produced (56%–85% Trial 1, 65%–85% Trial 2). We conclude that roe enhancement of H. erythrogramma collected from barrens is highly feasible.

Microalgae as sustainable food and feed sources for animals and humans – Biotechnological and environmental aspects

Offering a potential solution for global food security and mitigating environmental issues caused by the expansion of land-based food production, the carbon-hunger and nutrient-rich microalgae emerged as a sustainable food source for both humans and animals. Other than as an alternative source for protein, microalgae offer its most valuable nutrients, omega-3 and 6 long-chain polyunsaturated fatty acids where the content can compete with that of marine fish with lower chemicals contamination and higher purity. Furthermore, the colorful pigments of microalgae can act as antioxidants together with many other health-improving properties as well as a natural colorant. In addition, the supplementation of algae as animal feed provides plentiful benefits, such as improved growth and body weight, reduced feed intake, enhanced immune response and durability towards illness, antibacterial and antiviral action as well as enrichment of livestock products with bioactive compounds. The significant breakthrough in algal biotechnology has made algae a powerful “cell factory” for food production and lead to the rapid growth of the algal bioeconomy in the food and feed industry. The first overview of this review was to present the general of microalgae and its potential capability. Subsequently, the nutritional compositions of microalgae were discussed together with its applications in human foods and animal feeds, followed by the exploration of their economic feasibility and sustainability as well as market trends. Lastly, both challenges and future perspectives were also discussed.

Dietary supplementation of microalgae, Aurantiochytrium sp. and co-feeding with Artemia enhances the growth, stress tolerance and survival in Penaeus monodon (Fabricius, 1798) post larvae

In global aquaculture industry, shrimp farming plays a key role and microalgae signify a vital part. The present study focussed to analyse the influence of dietary inclusion of Aurantiochytrium sp. MBTDCMFRIJMVL1, a heterotrophic marine protist as well as co-feeding with Artemia, on the growth and survival in black tiger shrimp (Penaeus monodon). The nutritive quality, with a total protein content of 54% and total fat content of 26% on dry matter basis along with good fatty acid profile and carotenoids makes Aurantiochytrium sp. a promising candidate for aquaculture nutrition. In the present study, three type of micro diets were designed (iso11-nitrogenous and isolipidic) with 50% crude protein and 8% crude fat viz., control diet (C), 1% inclusion of algae (T1) and 2% inclusion of algae (T2) and fed to the post larvae (PL) of P. monodon. There were six treatments in triplicate as follows; control (C), control accompanied by co-feeding with Artemia nauplii (C + A), 1% dietary inclusion of algae (T1), T1 with co-feeding (T1 + A), 2% dietary inclusion of algae (T2) and T2 along with co-feeding (T2 + A). 3600 numbers of PL with average length and weight 4.98 ± 0.13 mm and 1.51 ± 0.05 mg, respectively were randomly stocked in 18 rectangular glass tanks of 20 L water holding capacity with 200 PL in each tank and maintained at a salinity of 25‰. After the experimental period of 28 days, a better growth performance, survival rate, stress tolerance, nutritional quality and metabolic enzyme profile of the larvae were observed in ‘T2 + A' when compared to other treatments, while the lowest performance was observed in ‘C'. This study also concluded that, co-feeding with Artemia greatly enhanced the improvements brought by algal supplementation. Algal supplementation in the micro diet of P. monodon improved disease resistance against Vibrios. The fatty acid profile of PL28 were influenced due to algal supplementation. The levels of palmitic acid and docosahexaenoic acid (DHA) were higher and significantly different (P < 0.05) in P. monodon fed with algal supplemented diet, which reflected the fatty acid profile of Aurantiochytrium sp. This experiment revealed that dietary incorporation of Aurantiochytrium sp. at 2% level can significantly improve the growth, survival, nutritional quality and tolerance to stress in P. monodon post larvae suggesting its potential application in aquaculture.

Effects of dietary supplementation with algae, sunflower oil or soybean oil on folliculogenesis in the rabbit ovary during sexual maturation

This study aimed to examine the effects of algae (rich in omega-3 fatty acids), sunflower oil (rich in omega-6 fatty acids) and soybean oil (rich in omega-6 fatty acids) on the entire folliculogenesis in juvenile and sexually mature rabbits. After weaning, rabbits were randomly divided into four experimental groups of 14 animals each. Control animals received non-supplemented pellets, while in the other groups, the pellets contained 1% marine algae, 3% sunflower oil or 3% soybean oil. Animals from each group were slaughtered at 12 weeks of age (n = 7 per group) or at 18 weeks of age (n = 7 per group). The ovaries were harvested and fixed for hematoxylin-eosin staining, immunohistochemical localization of PCNA and TUNEL assay. Algae-enriched diet markedly decreased the number of primordial and primary follicles, while addition of sunflower oil reduced the number of primary follicles in 12-week-old rabbits. The number of antral follicles was higher following algae supplementation, but lower after addition of soybean oil in that age group. Proliferating index was decreased following supplementation with algae and soybean oil in juvenile rabbits, whereas it was increased after addition of algae and decreased following vegetable oils in mature ones. Dietary PUFAs did not impact apoptosis in the rabbit ovary of both age groups. The obtained results suggest that PUFA-enriched diet regulate either early folliculogenesis or antral follicle development in rabbits that might influence reproductive performance as a consequence. It appears that observed effects are attributed to sexual maturity.

Influences of dietary inclusion of algae Chaetomorpha aerea enhanced growth performance, immunity, haematological response and disease resistance of Labeo rohita challenged with Aeromonas hydrophila

The present study was investigated to the sequel of dietary supplementation of algae (Chaetomorpha aerea) on growth, exploitation of food, haematological, immunological parameters and disease resistance against Aeromonas hydrophila in Labeo rohita for 28-days trial period. A total of 180 fishes with a body weight of 55 ± 0.9 g initially, were selected and allotted to one of five dietary treatments, in which the basal diet supplemented with 0, 0.25, 0.5, 0.75, and 1.0 g kg−1 (w/w) of C. aerea. The fishes were subjected to challenge with Aeromonas hydrophila and relative percentage of survival (%) was recorded for 14 days after the feeding trial. Accordingly, the fishes fed with C. aerea increased the growth rate, feed conversion rate, specific growth rate, haemoglobin, neutrophil and lysozyme activity, when compared to the control group (P < 0.05). Moreover, C. aerea supplementation (0.25 g kg-1) showed that the enhanced body weight, respiratory burst and lysozyme activity and resistance against A. hydrophila challenge. On the whole, the obtained results showed that this feeding approach can productively increase the growth and it could be considered as a probable immunostimulant in the organic aquaculture.

The aqueous extract and powder of the brown alga Dictyota dichotoma (Hudson) differentially alleviate the impact of abiotic stress on rice (Oryza sativa L.).

Algal supplements can improve crop productivity and afford protection against abiotic stress by virtue of their rich content of plant nutrients and bioactive compounds. The present work investigates the relative efficiency of the biomass and extract of the brown alga Dictyota dichotoma in protection of rice against salinity and water stress. Rice (Oryza sativa L.) cv. Sakha 101 was grown on a silty clay soil amended with the aqueous extract and powder of D. dichotoma under NaCl and PEG 6000 stress at water potential of - 0.492MPa. Abiotic stress, particularly water stress, reduced rice growth and concentrations of K+ and protein but increased soluble sugars, starch, proline and Na+ concentrations of plant tissues, with counterbalancing effect of algal amendment. The benefit of algal amendment was greater for algal extract than algal powder and under water stress than salt stress. Algal amendment and abiotic stress promoted catalase and peroxidase activities in rice leaves with variable effect on polyphenol oxidase. The benefit of D. dichotoma to rice can be related to macro- and micro-nutrients, growth hormones, phenolics, flavonoids, sterols, vitamins and fucoidan. The production of toxic intermediates as a result of fermentation of the algal biomass in the paddy soil might reduce the benefit of algal amendment. Although rice is salt-sensitive, it is more resistant to salt stress than to drought stress. The ability of rice to retain Na+ in the root is pivotal for stress resistance, but the role of K+ partitioning is less evident.