Feeding Trial Research Articles

Dietary starch structure modulates nitrogen metabolism in laying hens via modifying glucose release rate

The objective of this study was to investigate the effects of starch structure (Amylopectin/Amylose, AP/AM) in a low-protein diet on production performance, nitrogen utilization efficiency, and cecal flora in laying hens. Four hundred eighty 45-wk-age Hy-Line Gray laying hens were randomly allocated to five dietary groups and subjected to a 12-wk feeding trial. The AP/AM ratios of the five experiment diets were 1.0, 1.5, 2.0, 3.0, and 4.0. The results indicated that compared to other groups, laying hens fed with AP/AM 4.0 diets showed significantly improved average egg weight and feed conversion ratio (P < 0.05). Furthermore, as the AP/AM ratio increased, there was a significant linear enhancement in intestinal amino acids apparent digestibility, apparent metabolizable energy, and villus area (P < 0.05). Compared to the high AP groups, high-AM diets significantly increased eggshell thickness, crude protein digestibility, and reduced energy supply from amino acid oxidation in ileum (P < 0.05). Additionally, moderate-AM diets enriched with short-chain fatty acid-producing bacteria in the cecum, such as Lactobacillus, Rikenellaceae_RC9_gut_group, and Christensenellaceae_R-7_group, which are associated with the promoting nitrogen utilization. These findings may offer useful information on optimizing starch structure for the design of food products and relevant therapies due to the potential effects on nutrient metabolism and gut homeostasis.

Dose-response curves for the effects of Lactobacillus plantarum on growth performance, feed utilization, and health status of Litopenaeus vannamei shrimp. Optimizing the economic efficiency of supplementation

Abstract A 14-weeks feeding trial was conducted to employ polynomial regression analysis to establish the optimal dosage of Lactobacillus plantarum (Lac) for enhancing the growth performance, digestive enzyme activities, and blood biochemical, redox balance, and immunity response of Litopenaeus vannamei shrimp (initial body weight = 2.94 ± 0.03 g). A total of 240 healthy Litopenaeus vannamei shrimp were randomly distributed into four equal groups and were fed diets containing 0, 200, 400 and 800 mg Lac /kg diet respectively for 98 days. Increasing the levels of dietary Lac cubically improved growth performance and feed utilization ( p &lt;0.01), the optimal doses were established at 600 and 650 mg Lac/kg diet, respectively. Muscles thickness decreased significantly in all treated group compared to the control ( p &lt;0.05). The dietary treatment quadratic ally affected total protein ( p &lt;0.0001), tri-glycerides ( p &lt;0.0001), and cortisol ( p =0.0097), the optimal responses were observed at 650, 700, and 600 mg Lac/kg diet, respectively. Meanwhile the activities of liver enzymes (ALT and AST), the levels of blood urea and digestive enzymes (amylase and proteases) were cubically enhanced by the treatment, the optimal dosages were at 600 and 650 mg Lac/kg diet for liver enzymes, and urea concentration, respectively and at 650 and 700 mg Lac/kg diet for the activities of amylase and protease, respectively. With regards to redox balance, increasing the levels of Lac caused a quadratic decrease in the levels of malondialdehyde ( p =0.0398) and a cubic increase in the activities of superoxide dismutase ( p =0.0265), and catalase ( p =0.0163), the corresponding dose–response curves showed that the optimal dose was at 650 mg/kg diet. However, the levels of total antioxidant capacity were in a quadratic increase ( p =0.0372), maximizing at a level of 600 mg Lac / kg diet. Concerning the immunity response, both of lysozyme and IgM significantly affected by the dietary treatment ( p =0.0002 and 0.0001, respectively), maximizing at 600 and 650 mg Lac/kg diet, respectively. Dietary supplementation of Lac had significant and substantial impacts on the economic efficiency ( p &lt;0.0001). In conclusion, the dietary inclusion of 600-700 mg Lac /kg diet can be used as an effective and practical feeding strategy to enhanced growth performance, feed efficacy, redox balance and nonspecific immune responses in Litopenaeus vannamei shrimp.

Microalgae and phytase dietary supplementation improved growth and gut microbiota in juvenile European seabass (Dicentrarchus labrax)

Fishmeal and fish oil have been the main sources of protein and fatty acid for aquaculture fish. However, their increasing price and low sustainability have led the aquafeed industry to seek sustainable alternative feedstuffs to meet the nutritional requirements of fish and improve their health and performance. Plant proteins have been successfully used to replace fishery derivatives in aquafeeds, but the presence of anti-nutritional substances is a potential drawback of this approach. Thus, it has been reported that phytate breakdown can be caused by feed supplementation with exogenous phytase. The inclusion of microalgae has been proposed to improve gut functionality in fish fed diets with a high vegetable protein content. The aim of this study was to evaluate the effect on the growth and gut microbiota of European seabass (Dicentrarchus labrax) juveniles of a diet containing a blend of microalgae (Arthrospira platensis and Nannochloropsis gaditana) and different concentrations of phytase. An 83-day feeding trial was conducted, comprising four experimental diets with 2.5% microalgae and 500, 1,000, 2,000, or 10,000 phytase units (FTU)/kg feed and a microalgae- and phytase-free control diet. At the end of the trial, a significantly increased body weight was observed in fish fed the diet with the highest phytase concentration (10,000 FTU/kg) versus controls, although the gut bacterial composition did not differ from controls in alpha or beta diversity with either majority (Weighted UniFrac) or minority bacterial strains (Unweighted UniFrac). In comparison to the control group, the groups fed diets with 1,000 or 2,000 FTU/kg diets had a lower alpha diversity (Shannon’s diversity index), while those fed diets with 500 FTU/kg or 1,000 FTU/kg showed distinct clusters in beta diversity (involving minority ASVs). According to these findings, the diet containing the 2.5% microalgae blend with 10,000 FTU/kg may be useful to increase the aquafeed quality and sustain the growth performance of juvenile European seabass.

α-Lipoic Acid Mitigates Heat Stress and Oxidative Damage in Broiler Chickens

Introduction: Heat stress has become a significant concern for the global poultry industry as a result of climate change. This condition can adversely affect growth, gut health, immune function, production levels, and reproductive performance, and can lead to lipid peroxidation in poultry. Therefore, this study aimed to evaluate Interleukin 6 and 10 immune responses, anti-oxidant indices, serum biochemistry, and hepatic and splenic histopathology of heat-stressed broiler chickens supplemented with α-lipoic acid (α-LA) in their diet. Materials and methods: A total of two hundred and four unsexed day-old Arbor acre broiler chicks were randomly divided into four treatment groups and replicated three times to receive α-LA at 0, 50, 100, and 200 mg/kg, respectively in a completely randomized design for 42 days after a one-week adjustment period. The average temperature in the morning and afternoon was 27.9℃ and 35.1℃, respectively, while the morning and afternoon humidity was 73.1% and 44.1% respectively. Feed and water were provided ad libitum. At the end of the feeding trial, samples were taken for cytokines (interleukin-6 and 10), anti-oxidant, serum biochemistry, and hepatic and splenic histopathology analyses. Results: An inverse relationship was observed between pro-inflammatory (IL-6) and anti-inflammatory (IL-10) cytokines whereby, IL-6 levels decreased while IL-10 levels increased relative to increasing α-LA levels in treatment groups. The treatment groups also indicated an increasing trend with rising levels of α-LA for superoxide dismutase, catalase, glutathione, and total antioxidant capacity. The α-LA significantly influenced malondialdehyde production, showing its reduction with rising levels of α-LA. A decrease in serum glucose and low-density lipoproteins was observed with increasing levels of α-LA, while high-density lipoproteins increased with increasing levels of α-LA. Cholesterol, triglycerides, very low-density lipoproteins, aspartate transaminase, alanine transaminase, and alkaline phosphate remained unchanged across the treatment groups. Conclusion: α-LA supplementation at 200mg/kg in diet had the highest effects on immune responses of interleukin 6 and 10, antioxidant, serum biochemical indices, and histopathology of heat-stressed broiler chickens.

Effect of two full-fat insect meals, yellow mealworm and black soldier fly larva, on growth performance of juvenile yellowtail

Abstract Given the expanding demand for fish meal (FM) worldwide, insect meal has become a promising alternative to FM for sustainable aquaculture. Yellowtail (Seriola quinqueradiata), the predominant farmed fish in Japan, is a carnivorous marine species that requires a substantial quantity of FM in its diet. Two feeding trials were conducted with the aim of assessing the applicability of two full-fat insect meals, yellow mealworm (Tenebrio molitor) meal (TM) and black soldier fly (Hermetia illucens) larvae meal (HI), as FM substitutes in for juvenile yellowtail. In the first trial, replacing 24.3% of FM with TM resulted in a final fish weight of 137.4 ± 40.1 g (mean ± SD as also indicated for subsequent values), comparable to the control group with a weight of 139.5 ± 44.0 g, while maintaining an equivalent level of n-3 fatty acid content across all diets used in the trial. The body weight of fish fed a diet containing HI, at 121.2 ± 31.0 g, was significantly lower than the control group, whereas the difference between fish fed a diet containing TM was not statistically significant. According to the growth analysis, dietary inclusion of TM was more suitable than that of HI, prompting a second trial to evaluate the maximum limit of FM substitution with TM without adjusting fatty acid profiles across diets. In the subsequent trial, fish growth exhibited a clear decrease trend with the inclusion rate of TM. These findings suggest that, while the substitution of FM with HI and TM has been shown to be feasible under equivalent fatty acid profiles in diets, the imbalanced fatty acid profile resulting from the inclusion of full-fat insects could be attributed to a deficiency in n-3 fatty acids, leading to the observed growth retardation in juvenile yellowtail.

Effects of dietary black cumin (Nigella sativa L.) meal on performance, blood metabolites, and digestibility in a rice straw-based diet of fattening Garut lambs.

During black cumin oil production, black cumin meal (BCM) is produced as a by-product. This study investigated the potential use of BCM to partly replace concentrate in a rice straw-based diet of fattening Garut lambs. Twenty-eight heads of male Garut lambs aged approximately10 months with an average initial body weight of 20.7 kg/head (coefficient of variation 12.9%) were used. A completely randomized design was used to compare four different levels (0% [control], 5% [BCM-5], 10% [BCM-10], and 15% [BCM-15]) of BCM in rice straw- and concentrate-based diets on the performance of Garut lambs during 35- and 70-day feeding trials using seven replicates (n = 7). Blood metabolites and nutrient digestibility were also measured after the performance study. BCM was rich in crude protein (36.8%) and tannins (21.6%). The BCM-10 and BCM-15 treatments increased (p < 0.05) average daily gain and feed efficiency compared with the control treatment in the 35-day feeding trial. All BCM treatments had greater dry matter (DM) intake compared with the Control at 70 days (p < 0.05). Furthermore, BCM-10 and BCM-15 had greater (p < 0.05) total protein, DM, and organic matter (OM) digestibility. BCM-15 had the highest (p < 0.01) blood triglyceride while BCM-10 tended to have higher (p < 0.1) blood glucose concentrations among the other treatments. BCM supplementation can partly replace concentrate and improve the overall quality of rice straw and concentrate-based diets, resulting in improved performance of fattening Garut lambs due to increased DM and OM digestibility, as well as protein and energy absorption. Approximately 10% of the BCM supplementation is suggested as the optimum level.

Effects of Formulated Pellet Feed or Live Fish Food on the Intestinal and Aquaculture Water Microbial Communities in Goldfish, Carassius auratus

This study investigates the impact of different diets on fish growth and bacterial community structure present in the intestine of goldfish (Carassius auratus) and their aquaculture water under recirculating water conditions. We assumed that different types of diet would form different intestinal microbiota that may affect host growth. Using Illumina MiSeq high-throughput sequencing, we analyzed bacterial communities in goldfish fed with formulated pellet feed, Tubifex worms (Limnodrilus hoffmeisteri), and an alternating diet of both. Over a 14-day feeding trial, no significant differences in juvenile goldfish growth were observed between groups. After 7 days, diet changes significantly influenced the abundance and diversity of intestinal bacteria, with the alternating diet notably enhancing bacterial diversity in both the intestines and water. However, these differences in bacterial diversity decreased by day 14. The results indicate that diet type affects microbial community diversity in the intestines and water of goldfish, and that goldfish intestines maintain a stable core bacterial community structure. This highlights the potential for optimizing diet types to enhance microbial health and stability in aquaculture systems and, in addition, provides an important scientific basis for alternative diets in goldfish aquaculture in the industry.

Dietary regulation of gut bacteria in the Pacific oyster Magallana gigas and Mediterranean mussel Mytilus galloprovincialis

Feed composition affects the gut bacterial community in aquatic species, but little is known about how diet type impacts gut microbiota in molluscan bivalves. This study investigates the impact of feed composition on the gut bacterial community in two commercially important bivalves: Pacific oyster Magallana gigas and Mediterranean mussel Mytilus galloprovincialis. Oysters and mussels were fed with two types of marine algae, live Isochrysis galbana (microalgae) and the dried seaweed powder Ulva sp. (macroalgae) under a laboratory condition for two months. The V1–V2 region of the 16S rDNA was sequenced through an Illumina MiSeq platform to compare the gut bacterial community of oysters and mussels at the start and the end of the feeding trial. Feed composition directly impacted both alpha and beta diversities of gut microbiota, but the degree of the impact differed between bivalve species. The difference in the gut bacterial assemblages of oysters and mussels in the pre- and post-feeding trials indicated that the diet type and host species shape the composition of gut bacteria. Spirochaeta was absent in mussel guts during the pre- and post-feeding trials but was present in oysters, revealing host specificity in colonizing gut bacteria. The results suggest that the diet type and host species can significantly impact the gut bacterial community structure. This study confirms that diet can modulate gut microbial composition in marine filter-feeding organisms, but the extent of dietary modulation depends on feed type and host species.

Modulatory Potential of Selenium Supplementations on the Growth, Nutrients Profile and Regulation of Antioxidant Status of Striped Catfish (Pangasius Hypophthalmus)

This study is designed to evaluate the impact of varying selenium levels on growth potential, nutrient profile and antioxidant enzymes activity in striped catfish. Fish were randomly allocated into 15 circular indoor tanks, each with a capacity of 2000 L, (100 (H) x 200 cm (D)) dimension, and were raised for 12 weeks. Fifteen fish were allocated to each tank across four separate treatment groups, each replicated three times, following an entirely randomized design. Five iso-nitrogenous diets (30% CP) were prepared from basal diet in which one was control and other four were supplemented selenomethionine (Se-met) with levels of 0, 0.5, 1.0, 1.5 and 2.0 mg/kg. Upon completion of the feeding trial, a diet containing Se at 1.5 mg/kg resulted in a significant increase (P&lt;0.05) in weight gain (229.60±3.00) and SGR (0.92±0.23), along with a lower FCR (2.18±0.32). While, proximate composition remains non-significant (P &gt; 0.05) against dietary Se feed. Antioxidant enzymes activity in liver and muscle found higher in Se1.5 diet and Se2.0 mg/kg diet in comparison to lower dietary Se treatments. Moreover, dietary Se1.5 and Se2.0 treatments values remained non-significant. Overall, the results indicated that the incorporation of Se-met at 1.5 mg/kg in the diet can improve growth performance and antioxidant status in P. hypophthalmus.

Short-term dietary supplementation of β-glucan and chitosan modulates the immune response in freshwater prawn, Macrobrachium rosenbergii (De Man, 1879)

Aim: The present study evaluates the immunomodulatory potentials of β-glucan and chitosan administered orally for 15 days to the freshwater prawn, Macrobrachium rosenbergii juveniles. Methodology: Two diets were formulated supplementing 1.5 g kg-1 and 20 g kg-1 of β-glucan (diet G) and chitosan (diet C), respectively, with a control diet (diet B). The prawns were fed twice daily at 5% biomass. At the end of the feeding trials, mRNA expression profiles of immune-related genes lipopolysaccharide- and β-1,3-glucan binding protein (LGBP) and chitinase 3 were analyzed in qPCR. Corresponding LGBP protein and chitinases/CBP (chitinase 1, chitinase 1C and obstructor E, a chitin-binding protein) protein levels were also estimated by ELISA. Results: Supplementation of the immunostimulants (diets G and C) significantly enhanced the mRNA expression of both LGBP and chitinase 3 in the hepatopancreas. The protein expression of LGBP and chitinases/CBP was also significantly increased in the serum and hepatopancreas samples of both treatment groups. Interpretation: The short-term supplementation of β-glucan and chitosan in diets demonstrated beneficial effects in M. rosenbergii by enhancing the expression of important immune molecules like LGBP and chitinases, indicating their potential applications during the period of biotic stress. Key words: β-glucan, Chitinase, Hepatopancreas, Immunostimulants, LGBP, Macrobrachium rosenbergii

Performance of grazing cows fed supplements from coproducts of biodiesel industry replacing soybean meal.

The objective of the present study was to evaluate the substitution of soybean meals by biodiesel co-products on the performance and nutrient balance of lactating cows on pasture. Twelve dairy cows (7/8 Holstein-Gir) in early lactation were included in this feeding trial. These animals had an average daily milk yield of 21.1kg and were distributed in a 4 × 4 triple Latin square experimental design. Protein supplements fed to these lactating cows contained peanut meal, cotton and sunflower as a complete replacement for soybean meal. Nutrient intake and digestibility, milk production, microbial protein synthesis, energy and protein balance were the parameters assessed in this study. Supplements containing different biodiesel co-products did not influence (P > 0.05) the level of forage intake, supplementation and nutrient by lactating cows, except for the total digestible nutrients (TDN) intake which was higher (P ≤ 0.05) in cows supplemented with cottonseed meal. The cotton meal also promoted higher digestibility of TDN (P = 0.001) and total carbohydrates (TCHO; P = 0.001) of the diet and, as a result, higher energy consumption (P = 0.01) and lower negative energy balance (P = 0.01). Cottonseed meal is a co-product of the biodiesel industry that has the ability to replace soybean meal as a source of protein in the supplement without affecting performance and promoting greater energy availability, demonstrating its ability to reduce the effects of negative energy balance in cows at the beginning of lactation kept on tropical pastures.

Evaluation of Growth Performance and Carcass Characteristics of Guraghe Bulls Under Various Feeding Regimes

The experiment was conducted on yearling Guraghe bulls, with an average initial body weight of 111.91 ± 3.98 kg, to evaluate their growth performances and carcass characteristics under three different feeding options and to identify the most economical dietary rations. Twenty-one experimental bulls were randomly assigned to three dietary rations: T1 = Rhodes grass hay ad-libitum + 20% molasses + 40% wheat bran + 40% noug seed cake, T2 = Rhodes grass hay ad-libitum + 20% maize grain + 45% wheat bran + 35% noug seed cake and T3 = Rhodes grass hay ad-libitum + 65% wheat bran + 35% cotton seed cake. The bulls were acclimatized to the experimental diets for days, and the actual feeding trial lasted for 26 weeks. The animals’ weights were recorded at 14-day intervals. At the end of the 26 weeks three bulls from each treatment group were randomly selected for carcass evaluation. There were no significant differences (P&amp;gt;0.05) in live weight parameters and carcass characteristics among the treatments. The overall means for total weight gain, average daily gain, and carcass dressing percentage were 112.86 kg, 620g/day, and 57.34%, respectively. The yearling Guraghe bulls did not reach export market weight within 26-weeks of the feeding period. Additionally, the partial budget analysis indicated that fattening yearling Guraghe bulls with the current feeding options were not profitable. This suggests that fattening Guraghe bulls with the current feeding options for twenty-six months is economically not viable. It is recommended to evaluate the growth performances of Guraghe bulls with other feeding options to achieve an export market weight of 250-300 Kg.

Comparison of Pediococcus pentosaceus YC64-fermented soybean meal and raw soybean meal in diets for Nile tilapia: Growth performance, feed utilization, and intestine health

Fermentation is a promising approach for improving the utilization of soybean meal (SM) by aquaculture fish, and the strain is the core of microbial fermentation processes. Herein, Pediococcus pentosaceus YC64, an autochthonous probiotic isolated from the intestine of Nile tilapia (Oreochromis niloticus), was applied to the fermentation of raw SM. In an eight-week feeding trial, tilapia juveniles were divided into two treatments fed on diets with 0 % (Control) and 100 % of SM protein replaced by fermented SM (FSM). Results showed that solid-state fermentation improved SM quality indicated by increased acid-soluble protein contents. Fish fed the FSM diet had significantly higher weight gain, feed efficiency, and protein efficiency compared to those fed the SM diet. Furthermore, whole-body protein content significantly increased in the FSM-fed fish, accompanied with the increased amino acid transport and reduced protein catabolism. Texture profile analysis indicated that fish fed the FSM diet had reduced muscle hardness compared with the control, which was associated with changes in collagen deposition and myofiber development. Moreover, feeding an FSM diet enhanced goblet cell proliferation and stimulated mucin secretion, ultimately leading to improved intestinal tight junctions and reduced inflammatory response. Besides, the FSM diet feeding altered intestinal microbiota community, characterized by increased abundance of Pediococcus. Overall, P. pentosaceus YC64 exhibits promise as a fermentation strain in the production of FSM. The FSM performed better than SM in improving the growth performance, feed utilization, and intestine health of Nile tilapia.

Feeding spent hemp biomass does not adversely affect fertility in rams.

To determine the reproductive effects of feeding spent hemp biomass (SHB) to rams. Several studies suggest cannabidiols negatively affect reproductive characteristics, and the reproductive effects of SHB ingestion have not been investigated in any species. Spent hemp biomass is high in protein and essential fatty acids, indicating a potential use in livestock diets pending studies investigating its safety in animals. Polypay rams approximately 6 months old were randomly assigned to 5 feeding trial groups (n = 7/group): either a low or high concentration of SHB in diet for either 4 or 8 weeks plus a control group. Blood samples were collected for hormone assays. At the conclusion of the feeding trial, the testes were removed, and sperm collected directly from the vas deferens were evaluated for motility (total, progressive, and speed), morphology, and concentration. A section from each ram's testes was formalin fixed, paraffin embedded, and subjected to routine immunohistochemistry to determine the expression of fertility-associated proteins deleted in azoospermia-like and Boule, followed by quantitative image analysis. Rams fed either 10% or 20% SHB for 8 weeks had significantly higher progressive sperm motility compared to controls. There were no significant differences between the treatment and control groups in the other parameters studied. Boule immunoexpression was adversely affected, whereas deleted in azoospermia-like immunoexpression was differentially affected by SHB ingestion. We conclude that up to 20% of the diet can be fed as SHB to rams for 8 weeks without adversely affecting testicular or sperm function. Supplementing young rams with SHB is unlikely to affect fertility.

Effects of Differently Processed Tea on the Gut Microbiota.

Tea is a highly popular beverage, primarily due to its unique flavor and aroma as well as its perceived health benefits. The impact of tea on the gut microbiome could be an important means by which tea exerts its health benefits since the link between the gut microbiome and health is strong. This review provided a discussion of the bioactive compounds in tea and the human gut microbiome and how the gut microbiome interacts with tea polyphenols. Importantly, studies were compiled on the impact of differently processed tea, which contains different polyphenol profiles, on the gut microbiota from in vivo animal feeding trials, in vitro human fecal fermentation experiments, and in vivo human feeding trials from 2004-2024. The results were discussed in terms of different tea types and how their impacts are related to or different from each other in these three study groups.

Elucidating the effect of dietary neem (Azadirachta indica) on growth performance, haemato-biochemical, immunonological response, and anti-pathogenic capacity of Nile tilapia juveniles.

This investigation attempts to evaluate the effect of diet additives via aqueous or ethanolic herbal extracts from Azadirachta indica leaves on Nile tilapia, Oreochromis niloticus. Five dietary categories were assigned to the fish: the first category (N1, with no extract) was kept under control conditions; two categories contained aqueous extract (N2 (1.0g/kg) and N3 (2.0g/kg); and two categories contained ethanolic extract, N4 (1.0g/kg) and N5 (2.0g/kg), with each group being fed for 60 days. After the feeding trial, Aeromonas hydrophila was injected intraperitoneally into fish for 14 days; fish mortality was recorded during this period. The results showed that the fish-fed dietary A. indica significantly improved growth performance and intestinal health (digestive enzymes and intestinal morphology), especially in the N4 and N5 categories. However, N4 and N5 categories demonstrated a significant decrease in AST and ALT activities and an increase in total protein, serum albumin, globulin, growth hormone (GH), leptin hormone (LEP), hemoglobin, white blood cells, and hematocrit (P < 0.05) in comparison with the control category (N1). Compared to the control category, the N4 and N5 categories have revealed a significant reduction in MDA activity and improvements in immunological activities (lysozyme, complement C3, and nitric oxide) and antioxidant enzymes (CAT, SOD, and GPX). Moreover, in tilapia-fed A. indica, the expression of IL-8, IL-1β, and Nf-κb genes was downregulated partially in the N4 and N5 categories than the control category. In contrast, the lysozyme, C3, GPX, and CAT genes were upregulated partially at N4 and N5 compared to the control category. Following the bacterial challenge, fish in the N4 and N5 categories also displayed the lowest fish mortality compared to the control category. The ethanolic extract displayed a more potent resistance against the parasite Cichlidogyrus tilapia in vitro than the aqueous and control categories, partially at 2g/L. According to these findings, an ethanolic neem extract (2.0g/kg feed) activates the immune system and antioxidant response in Nile tilapia fingerlings, improving growth and fish resistance to parasitic and bacterial infections.

Vitamin D3 alleviates the damage caused by high-fat and maintains lipid metabolism homeostasis in hepatopancreas by promoting fatty acid β-oxidation of Portunus trituberculatus

The purpose of present study was to evaluate the effects of vitamin D3 supplementation in high-fat diet on growth performance, calcium and phosphorus in tissue, immunity and lipid metabolism, and to explore whether adding vitamin D3 to high-fat diet can alleviate the adverse effects of high-fat diet on swimming crab (Portunus trituberculatus). The three experimental diets were normal fat diet (NFD, 9.35 % fat, 45.53 % protein), high fat diet (HFD, 14.69 % fat, 44.93 % protein) and high fat diet supplemented with 0.47 mg/kg VD3 (HFD+VD), respectively. A total of 108 healthy swimming crabs with an initial body weight of 9.42±0.13 g were selected for an 8-week feeding trial. The results showed that crabs fed with HFD+VD diet exhibited significantly higher percent weight gain (PWG), specific growth rate (SGR), feed efficiency (FE) and molting rate (MR) compared to those fed with HFD diet (P < 0.05). It was observed from hepatopancreas crude lipid content, TG content and hepatopancreas sections that HFD caused hepatopancreatic cell damage and abnormal lipid accumulation (P < 0.05), however, there were no significant differences in hepatopancreas crude fat content, TG content and hepatopancreas section observation between HFD+VD group and NFD group (P > 0.05). Crabs fed HFD diets with or without VD3 significantly down-regulated the expression of genes related to fatty acid transport, such as fabp9 and lpr1 in hepatopancreas (P < 0.05), moreover, the expression of genes related to fatty acid β-oxidation (cpt2 and acox1) were significantly up-regulated and genes related to lipid synthesis (fas and 6pgd) were significantly down-regulated in the hepatopancreas of the crabs fed with HFD+VD diet compared to those fed with HFD diet (P < 0.05). In conclusion, the results of present study indicated that a high-fat diet can cause deformation and rupture of hepatopancreas cells through abnormal lipid accumulation, thereby causing associated inflammation, leading to large calcium and phosphorus deposits in hemolymph and muscle, however, high fat diet supplemented with vitamin VD3 mainly enhanced the β-oxidation of fatty acids, inhibited lipid synthesis, alleviated abnormal lipid accumulation, and thus maintained the balance of lipid metabolism in hepatopancreas cells and promoted growth performance and feed utilization for swimming crab.

Sustainability and cost of typical and heart-healthy dietary patterns in Australia

Study objectiveThe aim was to quantify and compare the environmental and financial impact of two diets: a heart-healthy Australian diet (HAD) and the typical Australian diet (TAD). DesignThe study involved a secondary analysis of two modelled dietary patterns used in a cross-over feeding trial. SettingThe evaluation focused on two-week (7-day cyclic) meal plans designed to meet the nutritional requirements for a reference 71-year-old male (9000 kJ) for each dietary pattern. Main outcome measuresThe environmental footprint of each dietary pattern was calculated using the Global Warming Potential (GWP*) metric, taking into account single foods, multi-ingredient foods, and mixed dishes. Prices were obtained from a large Australian supermarket. ResultsThe HAD produced 23.8 % less CO2 equivalents (CO2e) per day (2.16 kg CO2e) compared to the TAD (2.83 kg CO2e per day). Meat and discretionary foods were the primary contributors to the environmental footprint of the TAD, whereas dairy and vegetables constituted the largest contributors to the HAD footprint. However, the HAD was 51 % more expensive than the TAD. ConclusionTransitioning from a TAD to a HAD could significantly reduce CO2 emissions and with benefits for human health and the environment. Affordability will be a major barrier. Strategies to reduce costs of convenient healthy food are needed. Future studies should expand the GWP* database and consider additional environmental dimensions to comprehensively assess the impact of dietary patterns. Current findings have implications for menu planning within feeding trials and for individuals seeking to reduce their carbon footprint while adhering to heart-healthy eating guidelines.

Supplementation of juvenile Siberian sturgeon (Acipenser baerii) diet with different levels of selenium: Growth performance, digestive enzyme activities, and intestinal histomorphology

This study aimed to investigate the impact of dietary Selenium (Se) on the growth performance, body composition, digestive enzymes, and intestinal histomorphology of Siberian sturgeon, Acipenser baerii. Fish (10.0±0.5 g) were randomly assigned to fifteen 1000-L tanks (30 fish per replicate) in a flow-through system and fed three times a day (08.00, 13.00, 18.00) with isonitrogenous (54.21 % crude protein) and isolipidic (15.63 % crude lipid) diets supplemented with selenomethionine at levels of 0, 0.2, 0.4, 0.8, and 1.6 mg kg−1 providing the analyzed Se of 0.10, 0.29, 0.49, 0.88, and 1.70 mg kg−1, respectively. Each three tanks were allocated to each treatment. After the eight-week feeding trial, weight gain ratio, specific growth rate, and survival rate of fish significantly increased with increasing dietary Se supplementation (p<0.05) and reached to the highest values of 156.00±0.68 %, 1.68±0.07 % d−1, and 98.33±1.66 %, respectively, while the feed conversion ratio declined to the lowest value of 1.79±0.10. Protein and lipid content increased with Se levels to the highest values of 20.15±0.11 % and 8.23±0.05%, respectively (p<0.05). Activity of all digestive enzymes including trypsin, chymotrypsin, α-amylase, lipase, and alkaline phosphatase significantly enhanced with increasing dietary Se levels (p<0.05). Increasing trends in villus height, villus width, muscle thickness, and crypt depth were found by increasing dietary Se supplementation with the highest values of 502.33±31.25, 134.39±13.12, 194.18±11.37, and 67.29±0.12 µm, respectively, in fish fed diet supplemented with 1.70 mg kg−1 Se (p<0.05). Findings of the present study illustrated the beneficial effects of dietary Se on performance, digestive enzymes, and intestinal histomorphology of Siberian sturgeon. According to the polynomial regression analysis, the optimum dietary requirement of Siberian sturgeon was in the range of 1.47–1.69 g kg−1.

A preliminary study on the effects of substituting fishmeal with defatted black soldier fly (Hermetia illucens) larval meal on Asian seabass (Lates calcarifer) juveniles: Growth performance, feed efficiency, nutrient composition, disease resistance, and economic returns.

This study aims to develop an alternative aquafeed derived from insect meal for Lates calcarifer juveniles, with the objectives of exploring the physiological performance, biological parameters, and economic analysis of substituting fishmeal (FM) with defatted black soldier fly (Hermetia illucens) larvae (BSFL) as part of the diet of L. calcarifer juveniles. Five practical diets were formulated to include 0% (BSFL0, serves as control group), 5% (BSFL5), 10% (BSFL10), 15% (BSFL15), and 20% (BSFL20) of BSFL meal, partially or fully replacing FM, respectively. Each diet was randomly assigned to triplicate groups of 30 fish (10.70 ± 0.07 g) per tank (300 L). The fish were fed twice daily to apparent satiation. A 56-day feeding trial was conducted to evaluate the impacts of defatted BSFL meal replacing FM on the growth performance, feed efficiency, composition analysis of fish muscle, cumulative mortality rate challenged with Vibrio parahaemolyticus, and economic returns of L. calcarifer. These results show that differences in weight gain and specific growth rate among the different treatments were statistically significant (p < 0.05), except for the absence of significant variation (p < 0.05) between BSFL0 and BSFL5, and followed by BSFL10 > BSFL0 > BSFL5 > BSFL15 > BSFL20. However, the feed conversion ratio and protein efficiency ratio showed the opposite trend as above. Although the diets experienced a decline in crude protein content and an increase in crude fat content with the increasing proportion of BSFL substituting FM, the crude protein and fat content of fish muscle were only slightly influenced. It is worth mentioning that levels of nonessential amino acids, delicious amino acids, saturated fatty acids, omega-6, omega-9 in BSFL10 group all showed an increase compared with the control group. After a 7-day challenge test with V. parahaemolyticus, the cumulative mortality rates of the BSFL5 and BSFL10 groups, respectively, dropped to 5.20%, 5.28% compared to the control group's 16.88%; however, the mortality rates of BSFL15 (34.67%) and BSFL20 (41.77%) groups were found to be significantly (p < 0.05) increased. From an economic perspective, the incidence cost for each experimental group showed a trend as BSFL10 < BSFL0 < BSFL5 < BSFL15 < BSFL20, whereas the profit index in each treatment exhibited the opposite trend as above. It was concluded that low (5%) or moderate (10%) levels of BSFL substituting FM in aquaculture feed could improve the physiological performances, disease resistance, and economic returns of L. calcarifer. However, excessive substitution (>15%) leads to a negative effect. From an economic point of view, 10% inclusion of BSFL in practical diets is recommended for L. calcarifer juveniles.