Natural Feed Research Articles

Efficiency of winter barley cultivation methods for herbage for bulk feed conservation

The article presents the results of the economic and bioenergetic assessment of winter barley cultivation methods for harvesting bulky fodder. In a short-term experiment the effect of five levels of mineral nutrition on two methods of tillage in the crop rotation link soybean – winter barley, on fused leached chernozems of the southern foothill zone of Adygea has been studied. Differentdepth methods of tillage have been used for 20–22 cm (plowing) and 12–16 cm (surface tillage). As a background on the variants, the main fertilizer ammophos and ammonium nitrate have been used as top dressings (N30; N45; N60). It has been revealed that the use of surface treatment reduces the yield of winter barley green mass by 21-41%. The average yield varied from 8.8 for surface tillage to 12.8 t/ha for plowing. The highest level of productivity is 19.2 for plowing and 12.0 t/ha for surface treatment. It has been revealed that the green mass of the studied varieties of winter barley in 1 kg of natural feed contains, on average, from 0.42 to 0.605 EFU (energy feed units). Analysis of the nutritional value of the obtained green mass has shown: in 1 kg of dry matter of feed for plowing: crude protein 10.1%, exchange energy 11.72 MJ, feed units (Ke) 1.12; for surface treatment – 8.8%, 11.72 MJ, 1.13 (Ke). The highest yield has been formed according to the cultivation method, with the introduction of 60 kg of a.i. N by background (N24 P104) – by plowing. The most profitable plowing option is: Background + N60 (Romans variety), with a yield of 19.2 t / ha, the profit from the sale is 10603.8 thousand rubles, the profitability level is 58.3%. Bioenergetic assessment of cultivation methods has shown that for each unit of energy invested in the production of winter barley green mass, on the best options, from 2.75 to 2.92 units of energy have been obtained.

Thermo-physiological responses and oxidative status of West African dwarf rams fed diets containing supplemental Tetrapleura tetraptera fruit meal

Plant secondary metabolites in Tetrapleuratetraptera fruit meal (TTFM) could be exploited as natural safe feed additives alternative to non- nutritive chemical and antibiotics to enhance rumen fermentation and feed utilization efficiency with negative oxidative stress. The study investigated the responses of West African Dwarf (WAD) rams to the diets containing varying levels of supplemental Tetrapleura tetraptera fruit meal on the oxidative status and thermo-physiological parameters. Thirty five (35) WAD rams with an average live weight of 13.20±0.2 kg were used in a completely randomized design for 140 days. Five concentrate diets containing varying levels (0, 0.5, 1.0, 1.5 and 2.0 %) of TTFM were formulated while Panicum maximum was fed as a basal diet. The rectal temperature, pulse rate and respiratory rate were measured at two week intervals while blood was collected through jugular veins at the onset and at the end of feeding trial to determine oxidative status parameters in terms of superoxide dismutase (SOD), glutathione peroxidase, thiobarbituric acid reactive substance (TBARS).Data collected were subjected to one way Analysis of Variance (ANOVA). No significant difference observed (p>0.05) in the rectal temperature while the pulse rate and breathing rate increased significantly (p<0.05) till 12th week of the experiment. Increased glutathione peroxidase, superoxide dismutase and lowered thiobarbituric acid reactive substance were recorded on the rams at the end of the feeding trial. It was therefore concluded that inclusion of Tetrapleura tetraptera up to 2 % level reduced the oxidative stress in the experimental animals coupled with better thermo-physiological responses

Nettle (Urtica dioica) Additive as a Growth Promoter and Immune Stimulator in Fish.

Aquaculture will become an important food production sector for humans in the coming decades. However, disease outbreaks can be considered a significant obstacle to continually developing aquaculture. Plant powders and extracts are natural feed additives that, due to their bioactive compounds, including phenolic compounds, proteins, vitamins, and minerals, have antistress, antiviral, antibacterial, and antifungal effects on fish. One of these herbs is nettle (Urtica dioica), which has a long history of being used in traditional medicine. While it has been widely investigated in mammalian medicine, few studies have been done on aquaculture species. The positive effect of this herb on the growth performance, hematology, blood biochemistry, and immune system of fish species has been observed. When fish were exposed to pathogens, nettle-fed fish showed a higher survival rate and less stress than controls. Therefore, this literature review is aimed at reviewing the use of this herb in fish diets and its impacts on growth performance, hematology, blood biochemistry, liver enzymes, immune system stimulation, and challenges with pathogens.

Epauletted fruit bats prefer native plants and contribute to seed dispersal in a South African agricultural landscape

AbstractFruit bats provide vital ecosystem services through seed dispersal aiding secondary forest regeneration. However, fruit bat species are often persecuted by fruit‐growing farmers due to perceived and actual crop damage. In this study, we investigated the dietary components of Epomophorous wahlbergi, Epomophorous crypturus and Rousettus aegyptiacus, which are the three fruit bat species commonly found in litchi orchards and surrounding natural habitats in the Limpopo Province, South Africa. We further explored the contribution of fruit bats to seed dispersal and germination success. Fruit bat diet was dominated by wild fruit species (95%), while commercial fruit contributed little (2%) to their diet, even during the litchi harvest season. Fig seeds (Ficus spp.) collected from captured bats as spit outs had significantly lower germination rates than regular seeds, but a significantly lower germination latency. A similar pattern was observed for quinine trees (Rauvolfia caffra). Our results suggest that fruit bats inhabiting orchards and surrounding natural vegetation feed primarily on wild fruit trees, probably modulated by the high percentage of natural vegetation still found in our study area, supporting the importance of natural habitats in mitigating crop damage. We encourage further work on potential disservices by fruit bats and their habitat use.

Application of Eugenol in Poultry to Control Salmonella Colonization and Spread.

The poultry sector is an essential component of agriculture that has experienced unprecedented growth during the last few decades. It is especially true for the United States, where the average intake of chicken meat increased from 10 pounds (4.5 kg) per person in 1940 to 65.2 pounds (29.6 kg) per person in 2018, while the country produced 113 billion eggs in 2019 alone. Besides providing nutrition and contributing significantly to the economy, chicken is also a natural reservoir of Salmonella, which is responsible for salmonellosis in humans, one of the significant foodborne illnesses around the globe. The increasing use of chicken manure and antibiotics increases the spread of Salmonella and selects for multi-drug resistant strains. Various plant extracts, primarily essential oils, have been investigated for their antimicrobial activities. The multiple ways through which these plant-derived compounds exert their antimicrobial effects make the development of resistance against them unlikely. Eugenol, an aromatic oil primarily found in clove and cinnamon, has shown antimicrobial activities against various pathogenic bacteria. A few reports have also highlighted the anti-Salmonella effects of eugenol in chicken, especially in reducing the colonization by Salmonella Enteritidis and Salmonella Typhimurium, the primary Salmonella species responsible for human salmonellosis. Besides limiting Salmonella infection in chicken, the supplementation of eugenol also significantly improves intestinal health, improving overall well-being. In this review, we highlight the rising incidences of salmonellosis worldwide and the factors increasing its prevalence. We then propose the usage of eugenol as a natural feed supplement for containing Salmonella in chicken.

Pengaruh Pengkayaan PUN – 11 (Perikanan Unaya 2011) dengan Limbah Sawi terhadap Jumlah Populasi Cacing Sutra (Tubifex sp.)

The success of cultivation is influenced by several aspects, one of which is the natural food in the hatchery or fish larvae phase. One type of natural feed that is suitable for fish larvae is silk worms (Tubifex sp.). But the availability of silk worms is still very limited, so further culture is needed. This study aims to determine the effect of PUN-11 enrichment with mustard greens waste on the growth of silkworm populations. The design used in this study was a comparative design consisting of 2 treatments and 3 replications. The treatments used were P1 (PUN = 11%) and P2 (PUN = 11%) + mustard greens waste (10%). The results showed that the highest population of silk worms (Tubifex sp.) was obtained in treatment P2 (PUN: 11 90% + mustard greens waste 10%), which was 3105 ind/cm2, and the lowest number of silk worms was in treatment P1 (PUN: 11 100%), which is 2868 ind/cm2. The results showed that the T test showed that P2 had a significantly different effect (P > 0.05) on the silkworm population growth.

Study of the effectiveness of a feed additive for calves based on fungi Trichoderma reesei and Ganoderma Lucidum

Gastrointestinal diseases occupy one of the leading places in terms of frequency and mass manifestation in the structure of pathologies of young farm animals. It is known that the main causes of the death of young cattle (cattle) are various viral and bacterial infections, as well as errors in keeping and feeding. Therefore, the development of feed additives from natural components, characterized by eco-friendly, cheapness, harmlessness in handling and technology in use, to reduce the incidence of animals due to nonspecific stimulation of protective mechanisms in the body remains an urgent task in the form of activation of bactericidal, lysozyme activity of blood serum. In this regard, the aim of the research was to determine the effectiveness of a natural feed additive consisting of the mycelial fungus Trichoderma reesei LA-531 VKPM F-184, a soil isolate – producer of cellulases and hemicellulases, which use to produce feed protein, with the addition of fungus Ganoderma Lucidum, which has an immunomodulatory, antitumor, antiviral, antibiotic properties and is widely used in biotechnology, and sphagnum moss. The experiments were conducted on the basis of the farm of LLC "Biruli" of the Republic of Tatarstan on calves of 2 months of age, with a live weight of 60-70 kg, divided into three groups of 10 heads each. Group 1 calves received a basic ration (BR) with the addition of feed grain mixed with a substrate (moss-sphagnum) at a dose of 1 % of the ration. The calves of the 2nd group received a developed feed additive in addition to the BR (at the rate of 1% of the diet). The calves of the 3 groups were given BR (biological control). The experimental period was 30 days. It is shown that daily addition of a feed additive at a dose of 1% of the basic diet increases the safety of young animals by 20.0 %, leads to a decrease in the incidence of gastrointestinal and respiratory diseases by 40.0 %, contributes to an increase in the average daily weight gain by 30.1 % compared with the control group.

Energy from Salinity Gradient of Wetland Saline Water Using Reverse Electrodialysis Membrane

Reverse electrodialysis (RED) membrane is an emerging renewable energy which harvest electricity from mixing two streams on different salinities. In real practice is still not clearly defined for the effectiveness of salinity gradient power (SGP)-RED due to the limitation of artificial saline water. Generally, South Kalimantan Indonesia is rich by wetland and coastal area. Due to that wetland saline water is potential as saline water sources for collection the SGP. This experiment aims to investigate the impact of natural feed stream wetland saline water was collected from Muara Halayung South Kalimantan-Indonesia to demineralized (WSW),artificial brackish (ABW) (0.35 wt %NaCl), and artificial seawater (ASW) (3.5 wt % NaCl) in terms of power density measured on a lab-scale RED membrane stack prototype 12 x 12 cm. Ion exchange membrane (IEM) was used in this work consisted from cellulose modified Anion Exchange Membrane (AEM) by EDTA-quaternization (EDC) process. Whereas, Cation Exchange Membrane (CEM) was employing Nafion NR-212 with thickness 0.002 in. Lab-scale RED tests operated 3 hours into area system has 121cm2; AEM and CEM area have 100cm2; uses spacer nylon a pair between membranes; and two electrodes by stainless-steal and copper. Feed water was into RED system then measured power density as an electrical energy potential that from separate ions by AEM and CEM. The result among of this experiment, characteristic of wetland saline water naturally had electro conductivity (EC) 135.6 µS/cm; TOM 15.2 ppm; and has ionic compound higher in Na+ and Cl- which is Cl- compound as one of potentially formed salinity on that wetland water and become potential uses one of natural feed water in RED system. The highest energy power density on RED process obtained by mixed WSW:ASW was 1.43 W/m2. While ratio of the gradient salinity WSW:ABW to ABW:ASW were increasing 86% which has 1:5 to 1:30 as the effect of stream mixing by two natural feed water.

Growth Performance of Clarias gariepinus Fingerlings Fed with Allium sativum Extract as Natural Feed Additives

Fish is an important aspect of global dietary consumption and its demand makes it an important source of income and means of livelihood. 120 Clarias gariepinus fingerlings were sourced from Nagwamatse Farms Gusau, Zamfara State. They were acclimatized for 14 days and fed 4mm Bluecrown containing 45% crude protein diet at 3% body weight twice daily at 12hours interval and later subjected to varying concentrations of garlic extract for the period of twelve weeks. Cloves of garlic were sorted to remove the off types. Garlic dried scales were removed to allow easy air-dry in the laboratory. Dried samples were pulverized using mechanical blender. Ethanolic extraction was done using 100g of powdered samples to 500ml of ethanol. The extract was used to compound fish feed in three treatment (0.5%, 1% and 1.5%). The C. gariepinus samples were divided into eight groups (three treatments and a control with one replicates each). Water parameters were measured daily. The average highest mean weight gain was recorded in 1% extract treatment with 155.8±6.4 and the least mean weight was observed in the fish fed with 0.5g/kg of concentrates (140.5±8.73). C. gariepinus showed evidence of positive growth response however, high and very low concentrations of garlic extracts had lower positive growth response. Further research should be carried out on the physiological effects of high concentration, its durational effects and, palatability test to further ascertain its potency. The aim of this research study was to evaluate the growth performance of Clarias gariepinus fingerlings fed with diets containing varying concentrations of Allium sativum extract.

Improving productivity in rabbits by using some natural feed additives under hot environmental conditions - A review.

Heat stress is a major challenge to animal production in tropical and subtropical climates. Rabbits suffer from heat stress more than farm animals because they have few sweat glands, and their bodies are covered with thick fur. Intensive farming relies on antibiotics as antimicrobials or growth promoters to increase animals' productivity and health. However, the European Union and many countries have banned or restricted the use of antibiotics in animal feed for human health concerns. Several studies have found that replacing antibiotics in rabbit feed with natural plants or feed additives increases productivity and improves immune capacity, especially under heat stress conditions. Growth performance, immune response, gut microflora, and carcass yield may be increased in rabbits fed a diet supplemented with some natural plants and/or propolis. In this review article, we discuss and summarize the effects of some herbs and plant extracts as alternative feed additives on rabbit productivity, especially for those raised under hot ambient temperatures.

Comparison of Artificial Feed and Natural Food by the Growth and Blood Biochemistry in Chinese Sturgeon Acipenser sinensis

As an endangered animal species, the Chinese sturgeon (Acipenser sinensis) has been artificially cultured during recent years. In the present experiment, the performance of a common formulated feed and a mixed natural feed on the growth and blood physiology of Chinese sturgeon were compared during one year of indoor culture. In terms of specific growth rate, the formulated diet group showed a higher value (4.2%) compared with the natural food group (−1.8%) during one year of indoor culture. Alanine aminotransferase activities of the sturgeons in formulated diet group was significantly higher than that in the natural food group throughout whole experiment period (p < 0.05). The total protein albumin, albumin and globulin contents of the natural food group were significantly higher than that of the formulated diet group in February and May (p < 0.05). The C-reactive protein contents of the formulated diet group were significantly higher than that of natural food group in May and August (p < 0.05). The activities of total cholesterol, high-density cholesterol, and low-density cholesterol were significantly higher in the natural food group than those in the formulated diet group (p < 0.05). The activities of triglycerides were significantly higher in the natural food group than those in the formulated diet group in February and May (p < 0.05). Almost half of the biochemical indicators examined show significant seasonal fluctuations, indicating that seasons have a substantial impact on the Chinese sturgeon. Overall, these results indicate that natural food exerted a positive impact on physiological indicators compared to the formulated diet.

Application of Baltic Pine (Pinus sylvestris) Needle Extract as a Gut Microbiota-Modulating Feed Supplement for Domestic Chickens (Gallus gallus)

The valorization of wood industry residues is very desirable from a circular economy perspective. Pine needle extracts are known for their health-promoting properties and therefore can be used as herbal remedies and nutritional supplements. Since the withdrawal of antibiotics as growth promoters in the European Union, natural feed additives that improve poultry health and production are needed. It was proposed that pine needle extract could be a good alternative to antibiotic usage at sub-therapeutic concentrations. The results relevant to our assumption could be obtained by using domestic chickens as an in vivo model for the evaluation of gut microbiota-altering properties of pine needle extract as an herbal supplement. We tested the antimicrobial effects of Baltic pine (Pinus sylvestris) needle extract. Then, we used chicken (Gallus gallus) that received feed supplemented with two different concentrations of the extract for 40 days to evaluate the changes in gut microbiota using 16S rRNA gene sequencing. This preliminary study demonstrated trends toward dose-dependent desirable changes in broiler microbiome, such as a reduction in the relative abundance of Campylobacter.

Design and optimisation of novel cascade mixed refrigerant cycles for LNG production – Part I: Benchmark cascade cycles

Complex cascade refrigeration cycles are typically used for production of liquefied natural gas (LNG). These include the propane precooled mixed refrigerant (C3MR) cycle, the dual mixed refrigerant (DMR) cycle, and the Phillips Cascade cycle. These are highly energy-intensive processes, resulting in many studies focusing on improving their energy efficiency by reducing their shaft power demand. However, their relative performance remains unclear. Modelling assumptions and natural gas feed differ across the published literature. This work models and evaluates these three commercial cascade cycles on a common basis of modelling assumptions, natural gas feed and process complexity (e.g. number of compression stages). However, the performance of the cycles cannot be compared meaningfully without first optimising the designs. The optimisation strategy proposed combines a genetic algorithm, which includes regeneration of the population to improve diversity, with a nonlinear optimisation. A case study demonstrates the effectiveness of this strategy. This work provides a meaningful comparison of the relative efficiencies of these commercial cascade cycles, to provide a basis for benchmarking novel cascade cycle options in a study to follow.

Chitosan: a promising natural polysaccharide feed additive in poultry production systems.

In recent years, the hazardous use of antibiotic growth promotors in the poultry industry has led to the development of drug resistance and violative tissue residues. Therefore, the European Union Regulation banned application of these growth promotors, and the international authorities have searched for other natural and safe feed additive sources as substitutes for antibiotics. Chitosan has been used as a feed-additive alternative in veterinary medicine practices worldwide. Chitosan and chitosan-based nanoparticles have been extensively investigated in the poultry production system and have proved several positive impacts. The overall performance parameters of broilers and layers have been improved following dietary treatments with chitosan. Besides, chitosan showed antimicrobial activity against many bacterial, fungal, viral, and parasitic diseases as well as boosting of the immune response. Modulation of the antioxidant activity and modification of some blood parameters have also been detected owing to dietary chitosan supplementations. Moreover, chitosan nanoparticles have been now applied as a vaccine delivery vehicle and a mucosal adjuvant for many important poultry bacterial and viral diseases. Therefore, this review article sheds light on the effects of chitosan and its nanoparticle forms on the production traits of broilers and layers, their antimicrobial, immuno-regulatory, and antioxidant properties, as well as their effects on the blood constituents and vaccine production.

Utilization of rotifers as natural feed in the rearing of saline nile tilapia (Oreochromis niloticus) larvae

After the yolk sac of fish larvae is absorbed, they will utilize external food sources such as natural phytoplankton and zooplankton. Specifically, one of the zooplankton species used is the small-sized rotifer Brachionus sp., which matches the mouth opening of the larvae. The purpose of the experiment was to examine the effects of providing live rotifer in combination with artificial feed on the survival rate and growth of Nile tilapia (Oreochromis niloticus) larvae in high salinity conditions. The Nile tilapia larvae used in the experiment were the offspring of Red Nifi strain breeders raised in freshwater and still containing yolk sacs. Feeding commenced after the yolk sacs were absorbed, and the salinity was gradually increased to 25-30 ppt. The larvae were fed with rotifers for seven days (P-1), 14 days (P-2), and then continued with another type of artificial feed. There was also a control group that only received artificial feed without rotifers. The stocking density of the fish larvae was 25 individuals per liter, and the total water volume used was 15 liters. The rotifer dose was maintained at 10-20 individuals per milliliter of water per day during the 4-week rearing period. The results showed that providing rotifers in water salinity between 10-15 ppt during the first seven days resulted in a survival rate of > 80%, whereas the control group achieved > 90% survival. However, the survival rate of the larvae started to decline from the second seven-day period with the increase in salinity between 15-25 ppt, and it continued to decrease to < 60% until the fourth week for all treatments.

Pelatihan Pembuatan Pupuk Organik Cair(POC) Pada kelompok Pembudidaya Ikan Bandeng di Kabupaten Pangkep

The community of milkfish cultivators who are members of the "Sipakatau" milkfish cultivator group in Pangkep Regency, until now still has various kinds of obstacles to increase its production. The problem is related to the use of chemical fertilizers before the stocking of milkfish seeds, the aim is to fertilize the growth of klekap and other phytoplankton to be used as natural food for young milkfish, so that it has an impact on the growth of green and blue algae that produce geosmin as the cause of the smell of mud and fishy in fish. milkfish. One alternative that is done to address this problem is to apply the use of liquid organic fertilizer (LOF). The method of implementing the activities is carried out using the methods of coordination, discussion, counseling, training and assistance to partners. Based on the results of community service activities carried out in the Sipakatau group, it can be concluded that so far this group of cultivators has used chemical fertilizers to increase the fertility of their pond soil. Through this training activity, the partner group became aware of and skilled in making and applying the use of liquid organic fertilizer (LOF) based on fermented duck manure to produce organic milkfish in Pangkep Regency. The advice given in this activity is that further assistance should be carried out regarding the use of LOF and applications in ponds so that environmental sustainability can be maintained through the use of organic fertilizers. Key Word: Milkfish, Natural feed, Pangkep, Liquid Organik Fertilizer

Case study on decarbonization strategies for LNG export terminals using heat and power from CSP/PV hybrid plants

The race towards decarbonization is driving major oil and gas companies to explore means to use renewable heat and power for their plants as part of their commitment to reduce their carbon intensity by 80% to 100% by 2050 (Holbrook, 2023). In terms of GHG (Greenhouse Gas) emissions, natural gas is considered the cleanest fossil fuel option available, and decarbonization of new LNG (Liquefied Natural Gas) projects is on the radar of many LNG projects developers. In addition, LNG cargos will have to be certified in the future by accredited authorities to meet defined GHG emission levels (Stern, 2019).This research study investigates a new concept of providing both heat and power from a PV (Photovoltaic) and CSP (Concentrated Solar Power) hybrid plant to meet the energy demand of an LNG export terminal. Two locations have been investigated for potential future LNG projects: Karratha in Australia and Ras Laffan in Qatar. Both locations have DNI values higher than 2000 kWh/m2/year, which is the minimum level required for CSP technology (Lovegrove and Stein, 2021).The LCCA (Levelized Cost of CO2 abatement) was used to compare the various solar configurations to select the option that will bring the greatest amount of CO2 reduction for the same investment cost (CGEP, 2020). The solar configurations technical parameters were defined based on the surface land available, natural gas feed composition and LNG plant design characteristics. The techno-economic assessment was carried-out taking into consideration the electricity price, the grid carbon intensity, and the CO2 tax in the region.Whilst in Australia a collocated single plant is favourable in terms of land availability and DNI (Direct Normal Irradiation) level, in Qatar, heat and power production have been separated into two distinct locations. Next to the LNG plant, a CSP plant provides heat only, whereas 130 km away, the hybrid PV/CSP plant located at Qurain EL Bawl provides electric power.The results indicate that the PV/CSP hybrid plant significantly accelerates the decarbonization of energy supply to the “All electric” LNG Plant. Depending on the solar field size, the quantity of CO2 emitted between 2025 and 2050 is reduced by 78–81% for Karratha (Australia) and by 82–88% for Ras Laffan (Qatar) compared to a grid connected plant.In addition, the economic assessment indicated that buying electricity from the grid during the period 2025–2050 would be more expensive for Australia then investing in a PV/CSP plant. In Qatar, the LCOE range of 93–110 US$/MWh is not competitive with the price of electricity in the region Qatar, mainly because of energy subsidies, however both the carbon tax and electricity price will need to be raised to the same level as in Australia to diversify and expand the power sector in the region.

Application of organic fertilizer originated from pond waste for white shrimp (Litopenaeus vannamei) grow-out in the extensive system

This study aims to evaluate the growth of natural feed, growth, survival rate, and production of white shrimp culture in an extensive system. A total of 9 ponds of 500 m2 were used as research containers. This study used a CRD with 3 treatments each with 3 replications. The treatments tried were: A = pond solid waste as organic fertilizer (2000 kg/ha) + Urea (100 kg/ha) + SP 36 (100 kg/ha), B = KCP PLUS + Urea (100 kg/ha) + SP 36 (100 kg/ha) and C= KM+Urea (100 kg/ha) + SP 36 (100 kg/ha). The test animals’ average weight of 0.027 g/ind, stocked at a density of 4 ind/m2. Supplementary fertilizer was given 10% of the initial dose and given every week. The results showed that the application of pond solid waste organic fertilizer gave a relatively similar response to the use of other commercial fertilizers on the growth of white shrimp. The survival and shrimp production significantly differed from other treatments. The abundance of individual phytoplankton ranging from 565-2588 ind/L and zooplankton ranges from 523-652 ind/L. The plankton diversity index (H’) ranges from 1.47-2.12, the uniformity index (E) ranges from 0.52-0.83, and the dominance index (D) ranges from 0.16-0.38.

Navicula sp Cell growth at different salinities

Navicula sp is one of the microalgae which plays an important role in fish and shrimp hatchery activities. Navicula sp. which can detect the surrounding environment and is able to adapt to various salinities. The purpose of this study was to determine the optimal salinity level for the growth of Navicula sp. The research was carried out on March 9 - 22 2022. The research location was carried out at the Natural Feed Laboratory of the Brackish Water Aquaculture Fishery Center (BPBAP) Ujung Batee Province of Aceh. This study used an experimental method with a completely randomized design (CRD), with 4 treatments and 3 replications. The treatment in this study is the difference in salinity: A (10 g/l), B (20 g/l), C (30 g/l), D (40 g/l). The results showed that treatment B with a salinity of 20 g/l had a significant effect (P <.0.05) on the other treatments. The results of the Duncan Significant Difference Test showed that the maintenance medium with a salinity of 20 g/l had the highest cell density (5.63x106 cells/ml), followed by the maintenance medium with a salinity of 30 g/l with a cell density (5.20x106 cells/ml)

VALIDATION OF THE METHOD FOR THE DETERMINATION OF RARE EARTH METALS IN BIOLOGICAL SAMPLES BY THE ATOMIC EMISSION INDUCTIVELY COUPLED PLASMA METHOD (ICP OES)

Currently, one of the priority nanomaterials are nanoparticles of rare earth metals (RЕM) – cerium, lanthanum, gadolinium and others, which allows them to be successfully used as new natural feed additives (due to their antimicrobial and antioxidant properties) in order to increase the productivity of animals. However, the issue of redistribution in the body and accumulation of RЕMs in livestock products requires an adequate answer using sensitive and highly accurate quantitative research methods, in connection with which the determination of RЕMs in biological samples becomes extremely relevant. Within the framework of this study, the suitability assessment (validation) of the developed method for the determination of RЕM (lanthanum and gadolinium) in biological samples (serum, liver, kidneys) using atomic emission inductively coupled plasma (ICP OES) was carried out and the method of sample preparation in various matrices was adapted. Key working parameters were determined as evaluation criteria: limit of detection, limit of quantification, accuracy, correctness, convergence, reproducibility, selectivity, linearity, working range. It was established that this method demonstrates good linearity in the working range of 1.0-500.0 μg/kg(dm3) for Gadolinium and 0.5-500.0 μg/kg(dm3) for Lanthanum; the method is selective, sensitive, practical and accurate. The limit of detection LOD and limit of quantification LOQ for Gadolinium and Lanthanum are 0.1 and 0.05 μg/kg(dm3) and 1.0 and 0.5 μg/kg(dm3), respectively. The validation data obtained meet the requirements of the Eurachem Guideline and the IUPAC Harmonized Guideline for Single-Laboratory Validation, and the method for the determination of RЕMs in biological samples is suitable for a specific application according to ISO/IEC 17025:2019.