Length Gain Research Articles

Chronic social isolation affects feeding behavior of juvenile zebrafish (Danio rerio).

Many organisms exhibit social behaviors and are part of some scheme of social structure. Zebrafish are highly social, shoaling fish and therefore, social isolation may have notable impacts on their physiology and behavior. The objective of this study was to evaluate the effects of social isolation on feed intake, monoaminergic system related gene expression, and intestinal health of juvenile zebrafish fed a high-inclusion soybean meal based diet. At 20 days post-fertilization zebrafish were randomly assigned to chronic isolation (1 fish per 1.5 L tank) or social housing (6 fish per 9 L tank) with 18 tanks per treatment group (n = 18). Dividers were placed between all tanks to prevent visual cues between fish. Zebrafish were fed a commercial fishmeal based diet until 35 days post-fertilization and then fed the experimental high-inclusion soybean meal based diet until 50 days post-fertilization. At the end of the experiment (51 days post-fertilization), the mean total length, weight, and weight gain were not significantly different between treatment groups. Feed intake and feed conversion ratio were significantly higher in chronic isolation fish than in social housing fish. Expression of monoaminergic and appetite-related genes were not significantly different between groups. The chronic isolation group showed higher expression of the inflammatory gene il-1b, however, average intestinal villi width was significantly smaller and average length-to-width ratio was significantly higher in chronic isolation fish, suggesting morphological signs of inflammation were not present at the time of sampling. These results indicate that chronic isolation positively affects feed intake of juvenile zebrafish and suggest that isolation may be useful in promoting feed intake of less-palatable diets such as those based on soybean meal.

Effects of Dietary Docosahexaenoic Acid (DHA) Levels on Growth Performance, Fatty Acid Profile, and NF‐κB/Nrf2 Pathway‐Related Gene Expression of Razor Clam Sinonovacula constricta

Dietary docosahexaenoic acid (DHA) is crucial for the optimal (Opt) growth of bivalves, but the precise dietary DHA requirement remains undetermined in bivalves. Our study identifies the optimal dietary DHA requirement for razor clam Sinonovacula constricta and demonstrates its effects on fatty acid profiles and gene expression related to inflammation and detoxification. Microencapsulated feeds with different DHA levels (DHA1–6 groups: 1.68, 4.85, 9.49, 12.6, 15.59, and 16.95 mg g−1 dry matter) were prepared using spray drying. Razor clams (initial wet weight: 3.8 ± 0.6 mg) were fed these microcapsules for a period of 20 days. The present study showed that the clams in the DHA1 group exhibited significantly lower weight and shell length gain rates compared to those in the DHA3, DHA4, DHA5, and DHA6 groups. Based on the shell length gain rate, the Opt dietary requirement of DHA for clam is approximately 6.42 mg g−1 dry matter. The clams in the DHA2 group had significantly higher crude lipid content compared to those in the DHA1 and DHA6 groups, while the clams in the DHA1 group had the highest ash content, significantly higher than that in the DHA4 and DHA6 groups. The DHA levels in the clams increased with the increase in DHA content in the microcapsules, while the levels of total n‐6 polyunsaturated fatty acids (PUFAs), linoleic acid (LA), and alpha‐linolenic acid (ALA) decreased. The mRNA levels of cyclooxygenase-2 (cox2) and 5-lipoxygenase type 2 (5-lox-2) were higher in the DHA1 and DHA6 groups compared to other microcapsule groups. As dietary DHA levels increased, the mRNA levels of nuclear factor kappa B (nfκb) and nuclear factor erythroid 2-related factor 2 (nrf2) decreased. Additionally, the mRNA levels of glutamate-cysteine ligase catalytic subunit (gclc) and glutathione S-transferase (gst) were highest in the DHA1 group. This is the first study to determine the Opt DHA requirement for juvenile razor clams using microcapsules with different DHA levels, and this study further reveals that dietary DHA can help reduce inflammation and oxidative status in clams.

Effect of food strategy and stocking density on larval performance of captively reared Mytilus galloprovincialis

Food availability is a crucial factor influencing the behavioral responses, development and physiology of bivalve’s larvae. In this study, we investigated the effects of two feeding strategies (Fv: number of microalgae cells per volume and Fb: number of microalgae cells per biomass) on Mytilus galloprovincialis larvae reared at three different stocking densities (D5: 5 larvae/ml, D15: 15 larvae/ml and D30: 30 larvae/ml). The results showed that larvae fed per volume (Fv) exhibited the highest survival rates across all tested densities (59%, 53% and 39% for D5, D15and D30 respectively), compared to larvae fed per biomass (Fb) (40%, 39% and 32% for, D15, D30 and D5 respectively). Conversely, feeding per biomass led to a significant increase in cumulative shell length gain (D5: 211.4 µm; D15: 214.99 µm and D30: 208.11µm) compared to feeding per volume (D5: 201.12 µm; D15: 166.23 µm and D30:130.09 µm). Statistical analysis revealed that food availability significantly influenced survival only at low larvae density (D5: F=20.13; P<0.01). However, it significantly affected cumulative gain only at high stocking densities D15 (F=148.96; P<0.001) and D30 (F=318.74; P<0.001). These findings emphasize the importance of feeding strategy and stocking density as crucial factors in regulating larval performance during captivity rearing.

Effects of long-term chlorpyrifos exposure on moulting and growth of Armadillo officinalis Dumèril, 1816 (Crustacea, Isopoda, Oniscidea)

The aim of this study was to evaluate the long-term effects of the insecticide chlorpyrifos on the moulting and growth of the terrestrial isopods Armadillo officinalis. Adult woodlice were exposed to chlorpyrifos at concentrations of 5, 10, 20, 40 mg/kg dry soil and compared to a control. During 100 days of exposure, effects on moulting and growth were investigated. The duration of premoult, ecdysis and intermoult stages were estimated. Also, the cuticle width (CW) and length (CL) were measured and their size increase and specific growth were calculated. The results showed that exposure to chlorpyrifos induced adverse effects on moulting in the terrestrial isopod Armadillo officinalis, mainly at the higher concentrations (20 mg and 40 mg/kg dry soil). Indeed, it decreased the percentage of moulting animals, delayed moulting, decreased the number of completed moult, extended the premoult stage, prolonged ecdysis, and reduced intermoult duration. Furthermore, these findings showed that chlorpyrifos exposure impaired also growth of Armadillo officinalis, mainly at the highest concentration (40 mg/kg dry soi), by decreasing weight gain (0.94 ± 2.14 mg), cuticle length gain (0.26 ± 0.06 mm) and specific growth rate (SGR) (0.04 ± 0.01 mm/days) compared to the control (Weight gain = 16.5 ± 1.84 mg; CL gain = 0.65 ± 0.07 mm; SGR = 0.08 ± 0.01). The present study highlighted the adverse effects of chlorpyrifos on moulting and growth of Armadillo officinalis, which raises concern about consequences of chlorpyrifos exposure on population dynamic of this species.

SAND CRAB (Emerita sp.) MEAL AS A NOVEL FEED INGREDIENT FOR KOI CARP (Cyprinus carpio)

Sand crab (Emerita sp.) is a marine biodiversity, but it has not been used as a fish feed ingredient. This study aimed to evaluate the nutritional value of sand crabs and to understand its effect when used as feed ingredient on the performance of Koi carp. The study was conducted in two steps, which is evaluation of the nutritional value of sand crab and its effect on fish performance. The proximate composition, amino acids, and fatty acids were measured using AOAC methods, and then the carotenoid content was determined by spectrophotometry. In the second step, the sand crab was added to fish feed at doses of 0, 5, 10, and 15 percent, and fed to koi fish for 42 days. The parameters observed were length gain (LG), weight gain (WG), and feed efficiency (FE). Nutritional data were analyzed by description and compared with fish feed ingredients from previous studies. Fish performance were analyzed by one-way ANOVA. When significant, Tukey’s significant mean test was applied. The result showed that the nutritional value of sand crab was comparable to other feed ingredients with a protein content of 37.88%, while carotenoid content was superior. The best performance of Koi carp was obtained with a dose of 15% sand crab in the diet, with LG, WG, and FE values of 0.93 ± 0.05 cm, 0.48 ± 0.06 g, and 63.50 ± 7.05 %, respectively. Based on this result, it can be concluded that sand crab has a high nutritional value and can be used up to 15% in Koi carp diet.

Suppressing of even harmonics in free electron lasers by modifying the energy spread of the beam

Using an analytical description of the evolution of the power of harmonics in free electron laser (FEL) undulators, we study the effect of electron beam parameters on the main characteristics of FEL radiation: the gain length, spectrum, and harmonic power. The possibility of suppressing even harmonics of the FEL as a light source in the study of materials and surfaces by analyzing the second harmonic nonlinear response (SHG) is being studied. The main factors influencing the radiation of even FEL harmonics are revealed; the influence of the beam cross section and the spread of electron energies on their radiation is analyzed. An example of a LEUTL FEL with visible light emission, which is used in studies of the optical properties of materials and the chemical state of molecules on surfaces and interfaces between media, is considered. In this context, the possibility of suppressing the second FEL harmonic is analyzed.

A Prospective Study of Graft Repositioning over Flap Technique for Reconstruction of Fingertip Amputation.

Background: Replantation of digital tip amputations, especially Allen III and IV, is challenging for hand surgeons as it requires a high level of microsurgical expertise and fine instruments. The graft repositioning over flap (GRF) technique is a simple and reliable procedure that provides length, sensation and nail growth and GRF has become popular in the last few years. The aim of this study is to report the short-term outcomes of the GRF technique. Methods: This is a prospective study of all patients who underwent a GRF reconstruction for Allen III and IV digital amputations at our hospital over a 12-month period. In addition to demographic data and injury details, we collected outcomes data with regard to flap and nailbed graft survival, capillary refill time, nail growth, sensation (2-point discrimination), bone union and gain in length of digit compared to length at injury. Results: Twenty patients underwent GRF reconstruction of digital amputation. They included 18 men and 2 women with an average age of 29 years. The thumb was the most frequently injured digit (n=7). Electric saws (n=5) and industrial machines (n=5) accounted for 50% of injuries. Twelve amputations were Allen IV. Five patients were lost to follow-up and outcomes data was available for 15 patients. There was loss of flap and nail bed in three patients. There was no growth of nail in three patients. The distal phalanx graft was lost in six patients and united in the remaining nine patients. Conclusions: The GRF technique is a simple and reliable option in patients in whom replantation is not possible. It restores length, provides sensation and nail growth in the reconstructed fingers. Level of Evidence: Level IV (Therapeutic).

The association of serum toxic metals and essential elements during early pregnancy with body mass index trajectory of infants during the first years: A prospective study

To the best of our knowledge, prior research has yet to delve into the combined and interactive relationships between maternal exposure to essential elements and toxic metals and infancy’s continuous growth and trajectories. This study aims to discern infant growth trajectories in the first year of life and to determine the associations of maternal serum levels of essential elements and toxic metals with growth trajectory. Within a Chinese prospective cohort in 2019 − 2021, 407 mother−infant pairs were included, and the serum levels of five essential elements (zinc, calcium, copper, magnesium and iron) and two toxic metals (cadmium and lead) in early pregnancy were assessed. The growth trajectory of infants was followed until age one year. Raw BMI and height values were transformed to age- and sex-specific BMI and height standard deviation (SD) scores. Latent-class group-based trajectory models and piecewise linear mixed regression were estimated to determine infant growth trajectories and growth velocity, respectively. The individual relationship between maternal metallic element levels and infant growth trajectory was examined using multinomial logistic regression models and linear mixed regression, while joint associations and interactive relationships were explored using Bayesian kernel machine regression (BKMR) following confounder adjustments. Four distinct trajectory patterns based on BMI-z score (low-rapid BMI gain group, normal-stable BMI group, very low-rapid BMI gain group and normal-rapid BMI gain group) and length-for-age (high-stable length group, low-stable length group, normal-rapid length gain group, very low-rapid length gain group) were identified during the first year post-birth, respectively. In single-metal and multiple-metal models, infants born to mothers with higher serum Zn and lower serum Cu levels were associated with a normal-rapid BMI gain trajectory during the first year. Serum Cu exhibited a positive correlation with the rate of BMI change solely in infants aged 6–12 months. Further, the BKMR analysis revealed a statistically significant and negative joint effect of the five essential elements on the likelihood of normal-rapid BMI/length gain trajectory when serum levels of these elements fell below the 70th percentile compared to median levels. In addition, high levels of serum copper and calcium interactively affect the rates of BMI change during 6–12 months old (β: −0.21, 95% CI: −0.44, −0.03, P = 0.04, P-interaction=0.04). In conclusion, maternal trace elements at early pregnancy are linked to infant growth patterns and growth velocity in the first year of life.

Growth Performance and Biochemical Composition of Nile Tilapia (Oreochromis niloticus) Reared in Membrane Bioreactor Treated Wastewater

The aquaculture sector in Africa has great potential for growth; however, it faces several challenges, one of them being the scarcity of clean water. This prompts the need for water recycling. The present study was conducted to investigate the effects of rearing Nile tilapia (Oreochromis niloticus) using municipal wastewater treated with membrane bioreactor (MBR) technology. A total of 270 Nile tilapia fingerlings (0.15±0.05 g) were reared in three treatment groups in triplicate. There were 2 treatments, including; MBR treated wastewater and stabilization pond treated wastewater (maturation pond), while the municipal tap water was used as the control. The growth performance (weight and length) of the fish was monitored over a 24-week period. After the experimental period, the biochemical composition of the fish muscle was analysed using standard AOAC methods. The results showed that the highest weight gain, length gain, survival rate, and specific growth were obtained in the fish in the control followed by the MBR treatment. Additionally, the crude protein, as well as the crude fiber and dry matter, were significantly higher in the fish in the maturation ponds at 23.10%, 0.29%, and 25.35%, respectively, while the crude ash was highest in the MBR at 1.22%. Results also showed that the MBR and maturation pond treatments meet the permissible levels for BOD, COD, NH4, and NO3 for water to be used in aquaculture. The bioaccumulation of heavy metals in the fish was mainly from the feed, with copper being the highest contaminant at 1.75 mg/100 g. In conclusion, both the MBR and maturation pond treated wastewater are viable for use in the rearing of Nile tilapia without adverse effect on the growth. However, MBR treatment showed better growth performance, suggesting that it could be used to increase productivity in fish farming.

Effect of Foeniculum vulgare Mingled Diet upon Growth, Reproduction and Spawning Performance of Guppy Fish

Naturally breeding fish cannot meet the demand of humans. So induced breeding is essential to fulfill this demand. Induced breeding ensures a timely supply of fish seeds having desired characteristics and different techniques can be used for this purpose. In this perspective synthetic hormones, extracts of pituitary hormones, Gonadotropin-releasing hormones, and sometimes Human chronic gonadotropin are used as a spawning inducer for fishes. Plant extracts can also be used as it is a new technique which could be used in aquaculture. The basic aim of our study was to enhance the growth as well as to check the effect of the traditional herb Foeniculum vulgare on the reproductive performance of Poecilia reticulata.
 Methodology: Samples were collected from a local fish shop in Sargodha. Ethanolic extract of Foeniculum vulgare seeds was prepared and mixed with different commercial feed. This feed was given to fish for 90 days to test the effect of Foeniculum vulgare seed extract on growth and reproduction performance. Water quality parameters were also maintained and recorded daily. Fecundity and Gonad somatic index were measured after dissection by removing the ovaries. Fecundity was calculated by counting the number of larvae and eggs seen with the naked eye. The hatching rate was measured by counting the number of hatching in each spawning.
 Results: According to the growth results, different levels of fennel seed extract has a significant effect on weight gain, length gain and survival rates of the fish in different groups. Statistical analysis cleared that T2 showed the highest weight and length gain. The feed Conversion Ratio decreased significantly. Results of reproduction parameters showed that the highest absolute fecundity (9.4 ± 0.19), GSI (8.69 ± 0.2) and spawning have increased in T2 followed by T1, T3, and control respectively. The observation of present research shows that Foeniculum vulgare seed extract can act as an estrogenic compound and growth promoter in commercial aquaculture.

Length and weight gain, AGR and IGR, KM and feed efficiency of Astronotus ocellatus, Melanochromis sp, Cyprinus carpio and Oreochromis niloticus cultured in biofloc

Length and weight gain, AGR and IGR, KM and feed efficiency of Astronotus ocellatus, Melanochromis sp, Cyprinus carpio and Oreochromis niloticus cultured in biofloc

Comparison of growth (length and weight) gain, TCA, TIC, KM, and feed efficiency of Pargo tilapia, UNAM cultured in Biofloc at 10 gL-1 salinity at different densities

Comparison of growth (length and weight) gain, TCA, TIC, KM, and feed efficiency of Pargo tilapia, UNAM cultured in Biofloc at 10 gL-1 salinity at different densities

Comparison of length gain, weight, AGR, ICT, KM, and feed efficiency of Pargo UNAM tilapia cultured in Biofloc inoculated with Scenedesmus sp and Pinnularia sp microalgae

Comparison of length gain, weight, AGR, ICT, KM, and feed efficiency of Pargo UNAM tilapia cultured in Biofloc inoculated with Scenedesmus sp and Pinnularia sp microalgae

Making of Biodegradable Plastic Based on Corn Starch (Amylum Maydis) with Addition of Acid (CH3 COOh) and Gliserol Plasticizer

Almost all countries face the problem of plastic waste due to the large production of conventional plastics and the long degradation process. Therefore, to protect nature from the accumulation of plastic waste, research on biodegradable plastics needs to be done. Biodegradable plastics are made from starch, cellulose, chitosan, and proteins extracted from renewable biomass. Starch for making biodegradable plastics can be obtained from plants, one of which is corn. This study aims to determine the effect of the composition of acetic acid, glycerol and corn starch on the quality of biodegradable plastics which include tensile strength, elongation and biodegradation. The independent variables were variations of acetic acid and glycerol. Control variables are plastic mold size, corn starch mass of 5 grams, other compounds outside the independent variables. The dependent variable is tensile strength, elongation and biodegradation. To test the tensile strength and elongation of biodegradable plastic, Ultimate Testing Machine Mini was used. The results showed that the addition of acetic acid and glycerol to the corn starch and glycerol blending material had an effect on increasing the tensile strength value and reducing the elongation and biodegradation values of biodegradable plastics. The highest tensile strength value is 50.04 Mpa, obtained from the addition of 1.44% acetic acid and 35.71% glycerol from a volume of distilled water of 70 ml. The highest length gain or elongation of 90% was obtained from the addition of 0.48% acetic acid and glycerol as much as 21.43% of the 70 ml volume of distilled water. Percent weight loss of the largest plastic obtained from the addition of acetic acid as much as 0.48% and glycerol as much as 21.43% of the volume of distilled water as much as 70 ml, which amounted to 93.33%.

Effect of tarpaulin pond on the growth and haematology of catfish (Clarias gariepinus)

The present comparative study investigated the haematological and growth parameters of catfish reared in both earthen and tarpaulin ponds. The growth response of the fish in both ponds such as overall weight gain, production index, survival rate, daily weight gain and length gain in the fish samples were determined. The overall weight gain in the catfish grown in earthen pond was higher (800 – 1000 g) than those from tarpaulin ponds (600 – 800 g). The production index of fish from earthen pond was higher than those of tarpaulin pond. The survival rate was higher in earthen pond (100%) than tarpaulin pond (80%). Moreover, daily weight gain and length gain were higher in earthen pond (12.50 g and 50 cm) than tarpaulin pond (10.00 g and 30 cm) respectively. Also, the haematological parameters such as the packed cell volume (PCV), haemoglobin concentration (HB), Red Blood Cell (RBC), White Blood Cell (WBC) count and other blood parameters of each of the blood sample, were determined using 5-part differential Haematology Auto-analyzer (Mindray BC 5300 model).Catfish from earthen pond recorded the highest haemoglobin value (8.68±0.15 g/dL) than that of tarpaulin pond (7.78±0.03g/dL) this means that the oxygen carrying capacity of blood of catfish from earthen pond is higher than those of tarpaulin pond. Packed cell volume (PCV) value was recorded the highest in earthen pond (25.00%) again than that of tarpaulin pond (23.50%). Earthen pond recorded the least white blood cell (WBC) count (5268.30±54.03 x 103/L) compared to that of tarpaulin pond (6170.50±37.09 x 103/L). Red blood cell (RBC) count was recorded the highest in earthen pond (2.74±0.01 x 106/L) than that of tarpaulin pond (2.18±0.01x 106/L). Blood of catfish from tarpaulin pond recorded the highest neutrophils (60%) than that of earthen pond (53%). Earthen pond recorded the highest leucocytes (40%) than that of tarpaulin pond (37%). Also, monocytes counts are higher in earthen pond (7%) than tarpaulin pond (3%). In conclusion, the results of the present study indicated that the type of pond material used to rear fish can alter growth and haematological parameters.

Effect of partially hydrolyzed synbiotic formula milk on weight gain of late preterm and term infants-a multicenter study.

Data on the effectiveness of hydrolyzed infant formula containing both pre- and probiotics (synbiotic formula) on the growth of infants is still scarce. This retrospective study was designed to evaluate the effect of a partially hydrolyzed synbiotic formula on growth parameters and the possible occurrence of major gastrointestinal adverse events or morbidities in infants born via cesarean section (C-section) delivery. C-section-delivered term and late preterm infants who received either partially hydrolyzed synbiotic formula, standard formula, or maternal milk and followed at seven different hospitals from five different regions of Turkey, during a 1-year period with a minimum follow-up duration of 3 months were evaluated retrospectively. All the included infants were evaluated for their growth patterns and any kind of morbidity such as diarrhea, constipation, vomiting, infection, or history of hospitalization. A total of 198 infants (73 in the human milk group, 61 in the standard formula group, and 64 in the partially hydrolyzed synbiotic formula group) reached the final analysis. The groups were similar regarding their demographic and perinatal characteristics. No difference was observed between the three groups regarding gastrointestinal major side effects. Growth velocities of the infants in the human milk and partially hydrolyzed synbiotic formula groups during the first month of life were similar whereas the weight gain of infants in the standard formula group was significantly less than these two groups (p < 0.001). Growth velocities were similar among the three groups between 1st and 3rd months of age. A partially hydrolyzed synbiotic formula provided better weight gain in late-preterm and term infants who were delivered via C-section delivery compared to the standard formula during the first month of life. This weight gain was similar to the infants receiving exclusively human milk. This difference was not observed in length and head circumference gain. No difference was observed in any of the parameters during the 1st-3rd months of age. Specially formulated partially hydrolyzed synbiotic formulas may reverse at least some of the negative impacts of C-section delivery on the infant and help to provide better growth, especially during the early periods of life.

Utilisation of Maggots and Earthworms as Protein Supplement in The Feed of Clarias Gariepinus (Burchell, 1822)

Six months feeding trial was conducted to determine the growth performances of juvenile of Clarias gariepinus fed with varying replacement levels of Earthworm and Maggot meals. Proximate analysis was conducted using the procedure of Association of Official Analytical Chemist (AOAC) to ascertain the proximate compositions of Earthworm and Maggot. It was found that both Earthworm and Maggots have high protein content (42.95% and 40.33% respectively). Twenty-five (25) fingerlings of Clarias gariepinus were subjected to five different dietary treatments in replicate of 0%, 25%, 50%, 75% and 100%. Feedings were done twice a day (8am in the morning and 5pm in the evening) at 3% of their body weight, and the quantity of feeds was adjusted based on new weight gain. The morphometric measurements were carried out biweekly. At six months, the highest standard length (40.40 ± 0.50cm), total length (43.30 ± 1.00cm), and weight gain (485.10 ± 13.00g) was observed in 100% Earthworm and maggot meal, while the least standard length (32.60 ± 0.80cm), total length (35.90 ± 1.60cm) and weight gain (428.60 ± 4.50g) was observed in 0% Earthworm and Maggot meal. However, in all other growth performances and nutrient utilization parameters measured such as Relative growth rate, Specific growth rate, Feed intake, Protein efficiency ratio and Feed conversion ratio, 100% Earthworm and maggot had the best performance more than other treatments. There are no significant differences (P&lt;0.05) in survival rates in all the five different treatments. The results gotten from the water quality parameters showed no significant difference among all the treatment. Therefore, it can be concluded that combination of Earthworm and Maggot meal as a substitute to fish meal at 100% replacement level, in the diet of Clarias gariepinus could enhance growth without any adverse negative effect on the health, growth and development of juvenile of African catfish (Clarias gariepinus).

Growth and Survival of Philippine Endemic Juvenile Silver Therapon (Leiopotherapon plumbeus) Fed with Different Natural Live Feeds

Aquaculture of the endemic silver therapon (Leiopotherapon plumbeus) in Laguna de Bay is now seen as valuable instrument to improve its diminished stock and fisheries. Its dietary preferences during its early life stages are not yet well understood leading to low survival. Hence, the present study examined the effect of different natural live feeds namely, Panagrellus redivivus, Moina macrocopa, Artemia franciscana nauplii, and Paramecium caudatum, on the survival and growth of juvenile silver therapon after 30 days of feeding trials. Panagrellus fed silver therapon juveniles have better survival (97.85%, p&lt;0.05), followed by Artemia (54.37%), Moina (45.26%) and Paramecium (40.67%). For growth, a Panagrellus diet also resulted to significantly higher (p&lt;0.05) mean values for all parameters: weight gain (259.50 mg), length gain (13.40 mm), specific growth rate (5.60%), absolute growth (8.65 mg) and relative growth rate (5.08). Differences in the effects of different live feeds on the survival and growth of L. plumbeus juveniles may be at tributed to their different nutritional composition, with Panagrellus having better total crude protein and fat content, and amino acid and fatty acid composition, which are important in the overall metabolism, growth, development, and survival of fish. The present study demonstrates that provision of Panagrellus to L. plumbeus juveniles will result in significantly better survival and growth.

Effects of Platycladus orientalis Leaf Extract on the Growth Performance, Fur-Production, Serum Parameters, and Intestinal Microbiota of Raccoon Dogs.

Platycladus orientalis leaves are rich in flavonoids and polysaccharides, which offer high medicinal and nutritional benefits. This study aimed to investigate the impact of P. orientalis leaf extract (PLE) on the growth performance, fur quality, serum parameters, and intestinal microbiota of raccoon dogs. Sixty healthy male black raccoon dogs, aged 85 (±5) days, were randomly assigned to four groups and fed a basal diet supplemented with 0, 0.25, 0.50, and 1.00 g/kg PLE for 125 days (designated as groups P0, P1, P2, and P3, respectively). The results revealed that the raccoon dogs in group P1 exhibited increased average daily gain and underfur length while showing a decreased feed/gain ratio compared to group P0 (p < 0.05). However, the heart index in group P2 was significantly lower than in group P0 (p < 0.05), and the kidney index and serum alanine aminotransferase activities in group P3 were higher than in groups P2 and P0 (p < 0.05), suggesting potential adverse effects at higher PLE dosages. Notably, dietary PLE supplementation led to a reduction in serum glucose concentrations (p < 0.05), which may have implications for glucose regulation. Furthermore, the study explored the impact of dietary supplementation with 0.25 g/kg PLE on the raccoon dogs' intestinal microbiota using high-throughput sequencing. The results showed significant alterations in the microbial community structure, with a notable decrease in the abundance of Prevotella copri in response to 0.25 g/kg PLE supplementation (p < 0.05). In conclusion, supplementing raccoon dogs' diet with 0.25 g/kg PLE can lead to improved growth performance and a positive influence on the intestinal microbiota. However, caution should be exercised regarding higher dosages, as they may have adverse effects on certain parameters. As a result, PLE holds promise as a potential feed additive for fur animal production.

Effects of β-1,3-glucan on growth, immune responses, and intestinal microflora of the river prawn (Macrobrachium nipponense) and its resistance against Vibrio parahaemolyticus

In this study, we investigated the impact of β-1,3-glucan on the immune responses and gut microbiota of the river prawn (Macrobrachium nipponense) in the presence of Vibrio parahaemolyticus stress. Shrimps were fed one of the following diets: control (G1), 0.2% curdlan (G2), 0.1% β-1,3-glucan (G3), 0.2% β-1,3-glucan (G4), or 1.0% β-1,3-glucan (G5) for 6 weeks and then challenged with V. parahaemolyticus for 96 h. Under Vibrio stress, shrimps in G4 exhibited the highest length gain rate, weight gain rate, and survival rate. They also showed increased intestinal muscle thickness and villus thickness compared to the control and 0.2% curdlan groups. The apoptosis rate was lower in G4 than in the control group, and the digestive enzyme activities (pepsin, trypsin, amylase, and lipase), immune enzyme activities (acid phosphatase, alkaline phosphatase, lysozyme, and phenoxidase), and energy metabolism (triglyceride, cholesterol, glycogen, and lactate dehydrogenase) were enhanced. Expression levels of growth-related genes (ecdysone receptor, calmodulin-dependent protein kinase I, chitin synthase, and retinoid X receptor) and immune-related genes (toll-like receptor 3, myeloid differentiation primary response 88, mitogen-activated protein kinase 7, and mitogen-activated protein kinase 14) were higher in G4 than in the control. Microbiota analysis indicated higher bacterial abundance in shrimps fed β-1,3-glucan, as evidenced by Sob, Chao1, and ACE indices. Moreover, 0.2% β-1,3-glucan increased the relative abundances of Bacteroidota and Firmicutes while reducing those of Corynebacteriales and Lactobacillales. In summary, β-1,3-glucan enhances immune enzyme activities, alters immune-related gene expression, and impacts gut microbial diversity in shrimp. These findings provide valuable insights into the mechanisms underlying β-1,3 glucan's immune-enhancing effects.