Diet Formulation Research Articles

Phytogenic Feed Additives as a Sustainable Alternative to Antibiotics: Enhancing Growth and Disease Resistance in Nile Tilapia (Oreochromis niloticus)

Pathogens and challenging conditions in fish farming are common problems that cause mortality and reduce growth performance. Phytogenic feed additives can support the immunity of fish and thereby improve performance, production, and disease resistance. Two experiments with Nile Tilapia aimed to evaluate the effects of a matrix-encapsulated phytogenic additive (Digestarom® P.E.P. MGE) in different feed formulations, which vary in the marine meal inclusion level (5% and 12.8%), on growth performance and resistance against Streptococcus agalactiae. Fish were stocked in a recirculating aquaculture tank system per experiment and were fed with diets with or without the phytogenic supplementation for 8 weeks (six replicates per group). After an intraperitoneal injection with a sterilized saline solution and bath immersion with S. agalactiae (5 × 106 CFU/mL), mortality of the fish was recorded for 20 days. Independent of the diet formulation, the supplementation with the phytogenic feed additive significantly improved the fish production; feed conversion ratio; immune response (mainly lactic acid dehydrogenase, differential blood cell counts, and the lysozyme activity in blood); and fish survival after the S. agalactiae challenge. Thus, phytogenic feed additives are promising strategies to improve Nile tilapia production by enhancing fish growth performance, health, and protection against S. agalactiae infections.

Nutritional Performance of Extracted Soybean, Full-Fat Soya and Maize Gluten Meal Compared to a Fishmeal-Based Reference Diet for Juvenile Tilapia (Oreochromis Mossambicus)

Modern diets for aquaculture are highly complex and utilize a broad range of ingredients, including animal and plant byproducts. This study focused on the rationale of obtaining primary nutritional responses of tilapia evaluating two major ingredients, namely soybean meal and maize gluten meals by replacing fishmeal at set levels of incorporation. A two-onth investigation evaluated selected plant protein sources compared to fish meal protein in scientifically formulated diets for fingerling tilapia (Oreochromis mossambicus). Six nutritionally balanced diets: one reference (control) diet (fish-meal based diet), three selected plant proteins (solvent extracted soybean, full-fat soybean, and maize gluten) were substituted for the LT (Low Temperature dried) fish-meal-based control diet protein at 50% respectively, and the remaining diets were replaced with 75% inclusion of solvent extracted soybean and maize gluten meals. Results showed that solvent extracted soybean meal, 50 (SESB50), Full fat soybean, 50% (FFSB50) and Maize gluten, 50% (MG50) fed tilapia did not appreciably differ in their growth performance (percent weight gain of 279.36, 249.23, and 194.13% respectively) with a final mean weight of 14.95g being significantly superior (<0.05) for the fishmeal control (CO) group. Substitution of fish meal with solvent-extracted soybean and maize gluten at levels of 75% gave the poorest growth performance and Feed Efficiency (FE) (7.01g final weight, 51% FE). However, the MG50 diet also showed inferior feed utilisation performance. However, tilapia fed on a full-fat soybean diet (FFSB50) did not vary significantly from the control (CON) diet in terms of protein utilisation (ANPU) at 34.20% and 37.53% respectively. Whilst this preliminary study concluded that limitations on the use of the selected plant proteins in diets for tilapia are apparent, several approaches that could result in the future improvement of the nutritional value of soybean and maize gluten products for use in fish diets are also stated.

Dietary fiber content in clinical ketogenic diets modifies the gut microbiome and seizure resistance in mice

The gut microbiome modulates the anti-seizure effects of the ketogenic diet, but how specific dietary formulations differentially modify the gut microbiome in ways that impact seizure outcome is poorly understood. We find that medical ketogenic infant formulas vary in macronutrient ratio, fat source, and fiber content and differentially promote resistance to 6-Hz seizures in mice. Dietary fiber, rather than fat ratio or source, drives substantial metagenomic shifts in a model human infant microbial community. Addition of fiber to a fiber-deficient ketogenic formula restores seizure resistance, and supplementing protective formulas with excess fiber potentiates seizure resistance. By screening 13 fiber sources and types, we identify metagenomic responses in the model community that correspond with increased seizure resistance. Supplementing with seizure-protective fibers enriches microbial genes related to queuosine biosynthesis and preQ0 biosynthesis and decreases genes related to sucrose degradation and TCA cycle, which are also seen in seizure-protected mice that are fed fiber-containing ketogenic formulas. This study reveals that different formulations of ketogenic diets, and dietary fiber content in particular, differentially impact seizure outcome in mice, likely by modifying the gut microbiome. Understanding interactions between diet, microbiome, and host susceptibility to seizures could inform novel microbiome-guided approaches to treat refractory epilepsy.

Physiological and Metabolic Effects of Opuntia ficus indica spp. Peel Formulations

The objective of this study is to determine the physiological and metabolic effects of administration of dietary fiber formulations to male Wistar rats. The study population was divided into five groups to which food and water were orally administered ad libitum (control), alongside Psyllium plantago, sennosides A and B, cactus pear peel powder, and cactus pear peel tablet powder for 28 days. Body weight, biochemical parameters, fecal moisture, and intestinal transit were determined. The administration of the fiber formulations did not cause differences between the groups and they maintained a healthy weight; however, the consumption of the cactus pear peel tablet powder decreased serum glucose (127.85 ± 5.37 to 68.30 ± 12.48 mg/dL) in rats in a similar form to Psyllium plantago (127.85 ± 5.37 to 96.96 ± 3.26 mg/dL) in comparison with commercial products for rats, and the cactus pear peel powder had lower triglyceride levels (49.52 to 74.44 mg/dL) than commercial products at the end of the treatment. The samples maintained normal HDL levels with the exception of Psyllium plantago that had a decrease in treatment after 28 days. The administration of formulations of dietary fiber of cactus pear peel had physiological and metabolic effects similar to those of commercial products without change in the growth of the animals. Therefore, it could be used in the pharmaceutical or food industry.

Inclusion of Dunaliella salina in cold extruded and softly dried diets as a promising way to enhance the quality of Paracentrotus lividus gonads

Abstract The unicellular alga Dunaliella salina is a good source of β-carotene whereas the macroalga Porphyra sp. is rich in flavor-enhancing amino-acids such as glycine. Therefore, this study focused on the development of new dietary formulations for Paracentrotus lividus, including D. salina, Porphyra or glycine, aimed at improving roe color and flavour. Five isonitrogenous and isoenergetic diets were produced by cold extrusion and soft drying, meant to protect carotenoids. Sea urchins were fed these diets every 2 days in a recirculating aquatic system, at 18ºC. At the end of 8 weeks all diets proved equally effective in promoting growth and improving the gonadossomatic index. However, there were differences in the feed conversion ratio, which was lower in sea-urchins grown upon a diet based on commercial macroalgae mix and supplemented with D. salina at 1.5% (D2). Notable differences were found between males and females on carotenoids deposition in both gut and gonads, gonadal proximal composition, volatile compounds and anti-oxidant activity. This suggests sex-related differences in both nutrient assimilation and several metabolic processes. Gut carotenoids were influenced by both sex and diet, but gonads carotenoids were only affected by sex. All diets supplemented with Dunaliella improved gonad colour, resulting in redder and darker gonads when compared to a control (non-supplemented) diet. In particular D2 allowed to produce gonads with a higher colour saturation (C*) and the lowest hue angle (h*), comparable to a gourmet reference. Glycine supplementation and Porphyra led to an increase of sweet tasting amino acids in P. lividus roe. Dunaliella salina and Porphyra also increased umami tasting amino acids. The overall results point to D2 as the most promising formulation for P. lividus grow-out, as it allowed to obtain good colour roe at a lower feed conversion ratio.

Effects of Lysophospholipids on the Antioxidant Capacity, Digestive Performance, and Intestinal Microbiota of Litopenaeus vannamei.

This study seeks to assess the impact of varying concentrations of lysophospholipids on the antioxidant capacity, digestive performance, and intestinal microbiota of L. vannamei. A total of 840 shrimp, with an average initial weight of 2.22 ± 0.11 g, were randomly distributed across 28 aquaculture tanks (30 shrimp per tank), organized into 7 distinct treatment groups, each comprising 4 replicates. The control group (DL2) was administered a basal diet formula supplemented with 2% soy lecithin, whereas the experimental groups received lysophospholipids at varying concentrations of 0% (RL0), 0.1% (RL0.1), 0.5% (RL0.5), 1% (RL1), 1.5% (RL1.5), and 2% (RL2). The results revealed that the total antioxidant capacity (T-AOC) level in the RL0.1 group was significantly elevated compared to the DL2 and RL2 groups (p < 0.05). Furthermore, glutathione peroxidase (GSH-Px) and catalase (CAT) activities were markedly higher in the RL1 and RL1.5 groups relative to other groups (p < 0.05). Superoxide dismutase (SOD) activity exhibited a significant increase across all lysophospholipid-supplemented groups when compared to the DL2 group (p < 0.05). Malondialdehyde (MDA) levels were notably elevated in the RL0.5, RL1.5, and RL2 groups relative to the other groups (p < 0.05). Regarding antioxidant-related genes in the hemocytes, the relative expression levels of Nrf1, Nrf2, GPx, SOD, CAT, and Hippo were significantly higher in the RL0.5 and RL1 groups compared to the DL2 group (p < 0.05). Additionally, the relative expression levels of GPx and SOD were significantly elevated in the RL2 group compared to the DL2 group (p < 0.05). In the intestinal tract, the activities of trypsin and α-amylase (AMS) were significantly elevated in the RL0.1, RL0.5, and RL1 groups compared to the DL2 group (p < 0.05). Additionally, the RL0.1 group demonstrated significantly higher lipase (LPS) activity than the other groups supplemented with lysophospholipids (p < 0.05). Furthermore, the relative expression levels of the trypsin and α-amylase genes were significantly increased in the RL1 and RL1.5 groups in comparison to the DL2 group (p < 0.05). Sequencing analysis of the intestinal microbiota indicated that the incorporation of lysophospholipids resulted in an enhancement of the composition and structure of the intestinal microbiota. The functional abundance of the intestinal microbiome was primarily enriched in metabolic pathways. Overall, the incorporation of lysophospholipids into the diet exerted a beneficial effect on the antioxidant capacity, digestive performance, and intestinal microbiota of L. vannamei, especially with the supplementation of 0.1% lysophospholipids.

Impact of Hypocaloric Diets on Weight Loss and Body Composition in Obese Dogs: A Meta-Analysis.

Canine obesity is a complex, multifactorial condition marked by excessive body fat accumulation due to a sustained positive energy balance. Over the past decade, its global prevalence has risen significantly in most industrialized nations. Despite the availability of numerous commercial diets designed for obesity management in dogs, these products exhibit considerable variability in nutrient composition, and there is currently no standardized guideline on optimal macronutrient levels for effective weight loss. This study aimed to evaluate the effects of specific macronutrient levels on weight loss and body composition in obese dogs. A comprehensive literature search was conducted from 2022 to 2024 across PUBMED, Scielo, Web of Science, and Google Scholar. Out of an initial 1727 documents, 20 studies met the inclusion criteria and were incorporated into this meta-analysis. Diets with energy densities below 3.275 kcal, protein levels above 25%, total dietary fiber exceeding 12%, lower fat (<10%), and reduced non-nitrogenous extract (<40%) demonstrated beneficial effects on all evaluated parameters, including weight loss and body composition assessment. This meta-analysis provides evidence-based nutritional recommendations on optimal caloric, protein, fiber, fat, and carbohydrate levels for hypocaloric diet formulations, supporting healthy weight loss and lean mass preservation in obese dogs. These findings contribute to the development of effective dietary strategies that enhance canine quality of life and longevity.

Stability study of Ashtaguna manda As Ready-To-Eat (RTE) form – An Ayurveda Based Therapeutic Diet Formulation

Stability study of Ashtaguna manda As Ready-To-Eat (RTE) form – An Ayurveda Based Therapeutic Diet Formulation

Allzyme® Spectrum supplementation improves apparent ileal phosphorus digestibility and retention in older laying hens

Abstract Phosphorus (P) is required by laying hens for various biological functions, and it is usually provided in excess, in a readily digestible inorganic form in diet formulations. By adding enzymes to diets, the availability of phytate-bound P can be increased, allowing for the reduced inclusion of inorganic P in the diet formulation. The following study was conducted to examine the effect of a natural enzyme complex that contains phytase and xylanase on P digestibility in laying hens. Novogen Brown Classic layers (n=314, 95 weeks of age, approximately 14 weeks into second lay) were fed one of two diets; either a basal control diet or a the basal control diet plus a natural mixed-enzyme product (Allzyme® Spectrum; ASC, Alltech Inc, KY, USA) containing phytase (1000 SPU/g) and xylanase (7,500 EPU/g). The experimental diets were provided for 15 days, and excreta was collected from each pen at day 13–15 of the trial to determine total tract retention and apparent ileal digestibility of P and gross energy. At the end of the trial, birds were euthanised and ileal contents were collected. Productivity parameters, including egg production and feed conversion ratio, were recorded over the course of the study. The amount of P in the excreta from birds in the control group was significantly higher than the ASC enzyme-supplemented group. Both P retention, its ileal digestibility and gross energy digestion (ileum and total tract) were significantly higher in the ASC enzyme-supplemented birds. This study showed that the ASC enzyme supplement can improve the total retention and ileal digestibility of P and gross energy in older layers.

Single-Cell protein for feed and food

Abstract As global demand for protein sources continues to rise due to increasing populations and changing dietary preferences, the shortage of conventional protein for feed and food poses significant challenges for food security. Single-cell protein (SCP), derived from microorganisms such as yeasts and bacteria, represents a promising alternative to traditional protein sources. Among these, methanotropic bacteria such as Methylococcus sp. and Methyocystis sp. can provide protein from methane as their sole carbon and energy source. Oleaginous yeasts like Yarrowia lipolytica are gaining attention in animal nutrition, particularly chicken and aquaculture, since they not only contain protein but also lipids. Yarrowia lipolytica, which comprises approximately 20% lipids by cell weight, can effectively supplement protein in animal diets, improving feed efficiency and average daily gain (ADG). Incorporating 3% of this yeast instead of soybean meal can enhance growth performance, while higher inclusion rates may lead to adverse effects such as diarrhea in animals like piglets due to increased lipid content and reduced nutrient digestibility. The thick cell wall of Yarrowia lipolytica can limit nutrient absorption, indicating that lysis of the yeast cell walls may be necessary to optimize nutrient release. Additionally, the use of another oleaginous yeast, Lipomyces starkeyi, has demonstrated potential as a viable substitute for vegetable oils in fish diets, maintaining growth and meat quality without negative impacts. Research indicates that SCP can constitute significant portions of nitrogen intake in livestock, supporting performance without inducing adverse heat production. These findings underscore the potential of SCP and oleaginous yeasts in addressing protein shortages while promoting sustainable practices in animal nutrition. However, further studies are essential to optimize their utilization in various dietary formulations.

Improving protein hydrolysis and digestibility in Arthrospira platensis biomass through recombinant peptidases (EC 3.4): Opportunities for monogastric animal diets.

This study investigates the use of recombinant peptidases (EC 3.4) to improve protein hydrolysis and digestibility in Arthrospira platensis, with a focus on addressing the challenge of reduced protein bioavailability for monogastric animals due to resistant protein-pigment formations, such as phycocyanin, and increased digesta viscosity caused by jellification properties. A library of 192 peptidases was generated, from which 142 soluble peptidases were expressed in Escherichia coli and subsequently screened for activity against an A. platensis suspension in vitro. Among these peptidases, six promising candidates were identified for protein and peptide extraction from the microalga. These enzymes were tested individually, and in a mix (MIX6), and compared to commercial trypsin and pancreatin. Protein content was determined using the Bradford method and potential peptide formation was measured via an o-phthaldialdehyde (OPA) assay. The protein solubility and hydrolysis, specifically of two main protein fractions (18-26kDa and 40-48kDa) along with minor fractions, were analysed via 14% sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Results indicated that the enzyme ID 138, a serine-peptidase, significantly increased total peptide formation in the A. platensis supernatant, although it did not outperform other peptidases or enzyme mixtures. Notably, enzymes ID 152, derived from a marine bacterium, and ID 153, another serine-peptidase, exhibited significant improvements in the extraction and hydrolysis of one protein fraction (18-26kDa), possibly corresponding to a phycocyanin fraction. While no synergistic effects were observed among peptidases, further investigations are warranted to understand the enzyme composition of MIX6, particularly enzymes ID 138, ID 152 and ID 153, and their potential to enhance the bioavailability of A. platensis proteins for monogastric animals when incorporated into dietary formulations.

Investigating variability of craft microbreweries spent grains for classification and incorporation into precision diet formulation through multivariate analyses

Investigating variability of craft microbreweries spent grains for classification and incorporation into precision diet formulation through multivariate analyses

Dynamic Modeling for Prediction of Amino Acid Requirements in Broiler Diets

Accurate prediction of amino acid requirements in fast-growing broilers is crucial for cost-effective diet formulation and reducing nitrogen excretion to mitigate environmental impact. This study developed a dynamic model to predict standardized ileal digestible amino acid requirements throughout broiler growth using a factorial approach and the comparative slaughter technique, considering maintenance, growth, and gender factors. The model was based on an experiment were designed using 480 15-day-old Arbor Acres chickens randomly assigned to 10 groups. A linear equation was derived using established growth and protein deposition curves to calculate maintenance and growth coefficients. Models for five essential amino acids under different amino-acid-to-protein ratios were created (R2 &gt; 0.70). The model effectively estimated daily amino acid needs and specific time intervals. Comparisons with NRC (1994), BTPS (2011), and Arbor Acres manual (2018) showed higher predicted requirements for lysine, methionine, valine, and threonine than Arbor Acres (2018) and BTPS (2011), significantly exceeding NRC (1994). Arginine predictions aligned with BTPS in early stages, but were slightly lower in later stages. This supports the further development of dynamic amino acid models.

Genomic Analysis Reveals Novel Genes and Adaptive Mechanisms for Artificial Diet Utilization in the Silkworm Strain Guican No.5.

The transition from traditional mulberry leaf feeding to artificial diet cultivation represents a major advancement in modern sericulture, yet the genetic mechanisms driving this adaptation remain largely unexplored. This study investigates the genomic basis of artificial diet adaptation in the silkworm strain Guican No.5 through whole-genome resequencing and transcriptome analysis. We identified 8,935,179 single-nucleotide polymorphisms (SNPs) across all chromosomes, accounting for 2.01% of the genome, with particularly high densities observed in chromosomes 23, 26, and 28. Our analysis also revealed 879 novel transcripts, many of which are involved in digestion, detoxification, and stress response pathways. Key novel genes, including three carboxylesterases, two cytochrome P450s, one heat shock protein, and one copper/zinc superoxide dismutase, exhibited varying degrees of sequence similarity to known proteins, suggesting modifications to existing genetic frameworks. Notably, one novel P450 gene displayed only 74.07% sequence identity with its closest homolog, indicating the emergence of a new protein sequence. Additionally, several key genes showed high similarity to wild silkworm (Bombyx mandarina) proteins, underscoring their evolutionary origins. These findings provide valuable insights into the molecular mechanisms underpinning artificial diet adaptation in silkworms and offer genomic resources to enhance artificial diet formulations and breeding programs in sericulture.

Formulation and Nutritional Quality of Complementary Foods Developed from Red Beans, Orange-Fleshed Sweet Potatoes and Peanut Flour

Malnutrition and micronutrient deficiencies during infancy and early childhood are major problems facing developing countries, particularly Cameroon. This study aimed to formulate highly nutritious infant foods from locally available and affordable raw materials: orange-fleshed sweet potato (Ipomoea batatas L.), beans (Phaseolus vulgaris L.), and peanuts (Arachis hypogaea L.) grown in Cameroon. The formulated diets were analysed for their proximate (protein, fat, ash, fibre, carbohydrates), mineral (iron, zinc, calcium, magnesium, phosphorus), and antinutritional contents using standard methods. They were compared with the FAO/WHO standards. A total of two formulations were produced, with compositional proportions calculated based on recommended daily allowances (RDAs) for young children. The formulated ingredient varied 57-58% sweet potato, 23-25% beans, and 18-19% peanut. The linear programming method combined the samples into different formulations to meet FAO/WHO/UNICEF requirements. The results showed that the nutritional composition of the flour on a dry weight basis was as follows: crude protein: 12.66-13.66g/100g, lipid: 8.95-9.13g/100g, carbohydrates: 61.58-63.71g/100g, fibre: 5.58-6.22g/100g, ash: 3.82-4.64g/100g, energy: 381.53-387.65 Kcal, iron 9.45-10.46mg/100g, zinc 3.00-4.24mg/100g. The proximate contents of the formulated flours meet the FAO/WHO standards, except the energy content. The results of the study showed that the formulated diets contain very low antinutritional factors (phytate: 0.12 mg/100g and trypsin inhibitory content 0.30 to 0.35mg/100g). Based on the results, the complementary food formulated from sweet potato, beans, and peanut flour is a good source of protein, iron, and zinc and would contribute to the daily requirements of infants and young children.

Identification of Three POMCa Genotypes in Largemouth Bass (Micropterus salmoides) and Their Differential Physiological Responses to Feed Domestication.

Diverse feeding habits in teleosts involve a wide range of appetite-regulating factors. As an appetite-suppressing gene, the polymorphisms of POMCa in largemouth bass (Micropterus salmoides) were validated via sequencing and high-resolution melting (HRM). The frequency distribution of different POMCa genotypes were analyzed in two populations, and physiological responses of different POMCa genotypes to feed domestication were investigated. The indel of an 18 bp AU-rich element (ARE) in the 3' UTR and four interlocked SNP loci in the ORF of 1828 bp of POMCa cDNA sequence were identified in largemouth bass and constituted three genotypes of POMC-A I, II, and III, respectively. POMC-A I and Allele I had increased frequencies in the selection population than in the non-selection population (p < 0.01), 63.55% vs. 43.33% and 0.7850 vs. 0.6778, respectively. POMC-A I possessed the lowest value of POMCa mRNA during fasting (p < 0.05) and exhibited growth and physiological advantages under food deprivation and refeeding according to the levels of body mass and four physiological indicators, i.e., cortisol (Cor), growth hormone (GH), insulin-like growth factor-1 (IGF-1), and glucose (Glu). The identification of three POMCa genotypes, alongside their varying physiological responses during feed domestication, suggests a selective advantage that could be leveraged in molecular marker-assisted breeding of largemouth bass that are adapted to feeding on formula diet.

Comparative Physiological, Proteomic, and Metabolomic Insights into a Promising Low-Pruning Mulberry Cultivar for Silkworm Rearing.

Mulberry (Morus spp.) is an economically significant plant in the production of silk through feeding leaves to silkworm larvae. Traditional silkworm rearing is heavily labor-intensive, particularly in leaf collection, which leads to low efficiency and impedes the development of sericulture. Here, to assess the feasibility and effectiveness of a novel low-pruning mulberry cultivar, ZJ1, in the silkworm rearing industry, a comprehensive investigation integrating physiological, proteomic, and metabolomic analyses was conducted in comparison with the traditionally high-pruning cultivar, N14. The low-pruning mulberry variety ZJ1 exhibited a notable increase in annual leaf yield of 43.94%, along with a significant enrichment of serine and isoleucine contents, in contrast to those of the high-pruning variety N14. Through iTRAQ proteomics and LC-MS/MS metabolomics analyses, a total of 561 reduced and 803 increased differentially expressed proteins (DEPs), as well as 332 differential expressed metabolites (DEMs) in positive ions and 192 DEMs in negative ions, were identified in the ZJ1 group relative to the N14 group, respectively. The observed features in amino acid profiles and the enrichment of the sucrose-related metabolic pathway provided interesting insights for future endeavors in mulberry variety improvement and the optimization of silkworm diet formulations. Collectively, the low-pruning cultivar ZJ1, characterized by its rapid growth, high leaf productivity, and suitability for mechanized operations, is expected to be an efficient substitute in improving the future sericultural industry, especially in urbanized and industrialized regions.

Characterization of In Situ Ruminal Degradation of Crude Protein and Individual Amino Acids from Ryegrass

In temperate pasture-based dairy systems, ryegrass (Lolium perenne L.) is a key forage due to its high crude protein (CP) content, yet its rapid ruminal degradation could limit the supply of rumen-undegraded protein and essential amino acids (EAAs) to dairy cows. This study aimed to investigate the in situ ruminal degradability of CP and individual amino acids (AAs) in fresh ryegrass at the vegetative stage. Three second-parity, rumen-cannulated Holstein Friesian cows (487 kg body weight, 16.5 kg milk/day) were used for the incubation of ryegrass samples collected in different seasons at the vegetative stage. The degradation kinetics were assessed using the Ørskov and McDonald model, with mathematical corrections for microbial contamination. Results showed that the effective degradability (ED) of AAs was generally higher than that of CP (p &lt; 0.05), exceeding 2%, and that some EAAs, particularly lysine, exhibited an ED up to 5.5% greater than CP (p &lt; 0.05). These differences underscore the need for caution when using CP as a proxy for AA degradation in dietary formulations. Given the high degradability of ryegrass AAs, it would be important to monitor and adjust their supply in diets with high ryegrass inclusion to prevent potential deficiencies that could impair milk production and reduce feed efficiency.

Nutritional Value of Nannochloropsis oceanica for Weaner Piglets.

This study evaluates the nutritional value of spray-dried Nannochloropsis oceanica biomass to infer its applicability for weaner piglet feeding. Twenty-four piglets were randomly allocated to four dietary treatments (n = 6) with increasing N. oceanica inclusion (0, 5, 10, and 15%) levels. After a 4-day adaptation period, the digestibility experiment lasted two weeks, with daily excreta collection. Total tract apparent digestibility (TTAD), N balance, intestinal pH, histomorphology, and volatile fatty acid (VFA) concentrations were measured. No significant differences were observed in feed intake, growth, or intestinal morphology (p > 0.05). N intake increased linearly (p = 0.005) with N. oceanica inclusion, while N retention efficiency remained unchanged (p = 0.058). VFA concentrations decreased linearly (p < 0.001). The TTAD of dry matter (DM), organic matter, ether extract, and gross energy decreased (p < 0.05) with higher N. oceanica levels, while the ash TTAD increased (p < 0.001). The estimated TTAD values for N. oceanica biomass were 72.5% for DM, 82.9% for N, and 64.4% for gross energy. The digestible energy, metabolisable energy, and digestible crude protein values estimated for N. oceanica were 12.74 MJ/kg DM, 12.40 MJ/kg DM, and 20.4% DM, respectively. This information enabled the first nutritional characterisation of N. oceanica for weaner piglets, ultimately leveraging its use in piglet diet formulation.

GROWTH AND SURVIVAL OF SPINY LOBSTER, Panulirus homarus JUVENILES FED WITH DIFFERENT FORMULATED FEEDS

Article Highlights- Indonesia has remarkable natural resources of spiny lobster Panulirus homarus and an exceptional opportunity to establish the largest lobster aquaculture industry in the world.- However, culturing lobsters still relies on natural feeds (trash fish of fresh fishery by-catch) which are inefficient and environmentally unsustainable.- Developing formulated feed based on locally available ingredients is invaluable for replacing natural feeds to support sustainable lobster culture.- Formulated feed made of local fish meal provided the best growth of juvenile spiny lobster Panulirus homarus compared to imported fish meal. AbstractSeveral studies suggested that good growth performance and survival of lobster juveniles can be achieved by feeding the lobsters with formulated feeds. This study aimed to (1) evaluate the growth and survival of spiny lobster Panulirus homarus juveniles fed with different diets having profiles based on a basal diet formulation and (2) to compare the growth of lobsters fed with an identical formulated feed with variations only in sources of fish meal and dry matter content. The feeding experiment was designed following a completely randomized design (CRD) with five diet treatments and five replicates for each treatment. Five experimental diets were prepared in this experiment, i.e., Diet A (basal diet prepared as moist pellets); Diet B (moist pellets with the same formulation as Diet A, using local fish meal); Diet C (moist pellets with the same formulation as Diet A, using imported fish meal); Diet D (dry pellets with the same formulation as Diet A, using imported fish meal); and Diet E (fresh fish). Juveniles of spiny lobster with an average weight of 3.00±0.07 g were allocated in 25 net cages (60 x 60 x 60 cm) placed in a circular HDPE canvas tank (7.5 m in diameter) at a density of 15 lobsters/cage in a flow-through seawater system. The juveniles were fed with the experimental diets twice/day for 12 weeks. The experiment showed that the best growth was observed in juveniles fed with moist feed containing local fish meal (Diet B) with the final weight reaching 18.74±2.30 g. Moist feed containing imported fish meal (Diet C) resulted in a higher survival rate (46.66%), and the lowest survival rate (13.33%) was obtained from juveniles fed with fresh fish (Diet E).