Combined Supplementation of Two Selenium Forms (Organic and Inorganic) and Iodine in Dairy Cows' Diet to Obtain Enriched Milk, Cheese, and Yogurt.

This study evaluated the effects of dietary supplementation in dairy cows with two Se forms (organic and inorganic) and I at the maximum levels permitted in the European Union, with the aim to obtain naturally enriched milk and derived products. A total of 20 Holstein Friesian cows in lactation were fed 2 diets for 64 days: a control diet with a supply of 0.57 mg of inorganic Se and 0.57 mg of I per kg of ration in dry matter (DM), and an experimental diet (SeI) with a supply of 0.34 mg of inorganic Se, 0.23 mg of organic Se, and 5.68 mg of I per kg of ration in DM. The SeI diet did not modify the performance or, in general, the metabolic profile of cows. Se and I levels in milk were affected by diet type and time of measurement (p < 0.01). Thus, a marked increase of both microminerals was evident between the beginning and the end of the test, when the SeI diet was administered. For Se, this increase ranged from 1.95 to 3.29 µg/100 g of milk; and for I, from 19.69 to 110.06 µg/100 g of milk. The SeI diet increased (p < 0.01) the Se and I content in the cheese, reaching levels of 16.4 µg/100 g for Se and 269.7 µg/100 g for I. An increase in I was observed in yogurt from the SeI diet (p < 0.001). The supplementation of two forms of Se and I in the cows' ration, at the levels evaluated, produced milk and dairy products enriched in these microelements without altering their quality parameters. However, a responsible intake of these products is necessary to avoid risks of deficiencies or excesses that could negatively affect the health of consumers.

Performance and incidence of diarrhea in suckling Jersey calves supplemented with mineral-vitamin complex and Virginiamycin.

The rearing of calves is an essential activity of a dairy system, as it impacts the future production of these animals. This study aims to evaluate the incidence of diarrhea, performance, and blood parameters of suckling calves that received mineral-vitamin supplementation in milk plus virginiamycin that was offered in milk (via the abomasum) or by esophageal tube (via the rumen). Twenty-seven calves were used, from the first week to 60 days of age, submitted to the following treatments: CONTROL, without supplementation; MILK, supplementation of 20 g of a mineral-vitamin complex with 100 mg of virginiamycin, diluted in milk; RUMEN, supplementation of 20 g of a mineral-vitamin complex diluted in milk and 100 mg of virginiamycin in gelatin capsules via an esophageal applicator. MILK and RUMEN calves had lower fecal consistency scoring, fewer days with scores 2 and 3 throughout the experimental period, and lower spending on medication compared to the CONTROL animals. Supplemented calves had higher fat and protein intake and reached feed intake of 600 g earlier than CONTROL animals, but did not differ in performance and hematological parameters. Supplementation with virginiamycin and vitamin-mineral complex for suckling calves reduced the incidence and days of diarrhea, and reduced medication costs, with no difference in performance, but the supplemented animals had higher initial protein and fat intake and reached targeted feed intake earlier to begin the weaning process.

Assessment of the feed additive consisting of l-cystine for all animal species for the renewal of its authorisation (Bretagne Chimie Fine [BCF Life Sciences]).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the assessment of the application for the renewal of the authorisation of l-cystine as nutritional feed additive. The additive is authorised for use in all animal species (3c391). The applicant has provided evidence that the additive currently in the market complies with the existing conditions of authorisation. The EFSA Panel on Additives and Products or Substances used in Animal Feed concluded that the use of the feed additive in animal nutrition remains safe for the target species, the consumers and the environment. As regards the safety for the user, l-cystine is not an irritant to skin or eyes and is not a skin sensitiser. Exposure by inhalation of persons handling the additive cannot be excluded. The present application for the renewal of the authorisation does not include any modification proposal that would have an impact on the efficacy of the additive and therefore there is no need for reassessing the efficacy.

Arthrospira platensis enriched with Cr(III), Mg(II), and Mn(II) ions improves insulin sensitivity and reduces systemic inflammation in equine metabolic affected horses.

Equine metabolic syndrome (EMS) is a critical endocrine condition in horses, characterized by hyperinsulinemia, hyperlipidemia, and insulin resistance, posing a significant threat to their health. This study investigates the efficacy of supplementing EMS-affected horses with Arthrospira platensis enriched with Cr(III), Mg(II), and Mn(II) ions using biosorption process in improving insulin sensitivity and glucose tolerance, reducing inflammation, and mitigating obesity-related fat accumulation. Our results demonstrate that Arthrospira supplementation reduces baseline insulin and glucose levels, contributing to decreased adipose tissue inflammation. Furthermore, Arthrospira supplementation results in a decrease in body weight and improvements in overall body condition scores and cresty neck scores. Additionally, administration of Arthrospira leads to reduced levels of triglycerides and aspartate aminotransferase, indicating a decrease in hepatic adiposity and inflammation. These findings suggest that Arthrospira, enriched with essential micro- and macroelements, can be an advanced feed additive to enhance insulin sensitivity, promote weight reduction, and alleviate inflammatory processes, thereby improving the overall condition of horses affected by EMS. The use of Arthrospira as a feed additive has the potential to complement conventional management strategies for EMS.

Unlocking the potential of phenolated kraft lignin as a versatile feed additive.

Lignin, a renewable natural antioxidant and bacteriostat, holds promise as a versatile, cost-effective feed additive. However, traditional industrial lignin faces limitations, including low reactivity, poor uniformity, and unstable properties, necessitating chemical modification. Complex modification methods pose economic and toxicity challenges, so this study adopted a relatively simple alkali-catalyzed phenolization approach, using phenol, catechol, and pyrogallol to modify kraft lignin, and characterized the resulting products using various techniques. Subsequently, their antioxidant, antibacterial, adsorption properties for heavy metal ions and mycotoxins, growth-promoting properties, and antiviral abilities were assessed. The phenolation process led to lignin depolymerization and a notable increase in phenolic hydroxyl content, particularly in pyrogallol-phenolated lignin (Py-L), rising from 3.08 to 4.68 mmol/g. These modified lignins exhibited enhanced antioxidant activity, with over 99 % inhibition against E. coli and S. aureus, and remarkable adsorption capacities for heavy metal ions and mycotoxins. Importantly, Py-L improved the growth performance of mice and reduced influenza mortality. Furthermore, density functional theory calculations elucidated the mechanism behind the enhanced antioxidant properties. This study presents a promising avenue for developing versatile feed additives to address challenges related to animal feed antioxidant supplementation, bacterial control, and growth promotion.

Effect of a microencapsulated phyto/phycogenic blend supplementation on growth performance, processing parameters, meat quality, and sensory profile in male broilers.

Powered by consumer taste, value, and preferences, natural products including phytogenics and algae are increasingly and separately used in the food systems where they have been reported to improve growth performance in poultry and livestock. The present study aimed to determine the effects of a new feed additive, microencapsulated NUQO© NEX, which contains a combination of phytogenic and phycogenic, on broiler growth performance, blood chemistry, bone health, meat quality and sensory profile. Male Cobb500 chicks (n = 1,197) were fed a 3-phase feeding intervals; 1-14d starter, 15-28d grower, and 29-40d finisher. The dietary treatments included a corn-soy basal Control (CON), basal diet supplemented with NUQO© NEX at 100 g/ton from 1 to 28d then 75 g/ton from d 28 to 40 (NEX75), and basal diet supplemented with NUQO© NEX at 100 g/ton from 1 to 40d (NEX100). The NEX100 supplemented birds had 62 g more BWG increase and 2.1-point improvement in FCR compared with CON in the finisher and overall growth phase (p < 0.05), respectively. Day 40 processing body weights and carcass weights were heavier for the NEX100 supplemented birds (p < 0.05). The incidences of muscle myopathies were also higher in NEX treatments, which could be associated with the heavier weights, but the differences were not detected to be significant. The NEX75 breast filets had more yellowness than other dietary treatments (p = 0.003) and the NEX 100 treatment reduced the levels of breast filet TBARS at 7 days-post harvest (p = 0.053). Finally, both NEX treatments reduced the incidence of severe bone (tibia and femur) lesions. In conclusion, the supplementation of the phytogenic NUQO© NEX improved finisher performance parameters, whole phase FCR, processing carcass weights, and breast filet yellowness, at varying inclusion levels.

Impact of combined management strategies of monensin and virginiamycin in high energy diets on ruminal fermentation and nutrients utilization.

Feed additives such as monensin (MON) and virginiamycin (VM) are commonly utilized in feedlot diets to enhance rumen fermentation. Nevertheless, the precise effects of combining MON and VM during specific feedlot periods and the advantages of this combination remain unclear. This study was designed to investigate the effects of withdrawal of MON when associated with VM during the adaptation and finishing periods on ruminal metabolism, feeding behavior, and nutrient digestibility in Nellore cattle. The experimental design was a 5 × 5 Latin square, where each period lasted 28 days. Five rumen-cannulated Nellore yearling bulls were used (414,86 ± 21,71 kg of body weight), which were assigned to five treatments: (1) MON during the entire feeding period; (2) VM during the entire feeding period; (3) MON + VM during the adaptation period and only VM during the finishing period 1 and 2; (4) MON + VM during the entire feeding period; (5) MON + VM during the adaptation and finishing period 1 and only VM during the finishing period 2. For the finishing period 1, animals fed T3 had improved potential degradability of dry matter (p = 0.02). Cattle fed T3 and T5 had the highest crude protein degradability when compared to animals receiving T2 (p = 0.01). Animals fed T2 and T3 had reduced the time (p < 0.01) and area under pH 6.2 (p = 0.02). Moreover, animals fed T4 had greater population of protozoa from the genus Diplodinium (p = 0.04) when compared to those from animals fed T2, T3 and T5. For the finishing period 2, animals fed T3 had greater starch degradability when compared to animals receiving T4 and T5 (p = 0.04). Animals fed T3, T4 and T5 had increased the duration of time in which pH was below 5.6 (p = 0.03). The area under the curve for ruminal pH 5.2 and pH 5.6 was higher for the animals fed T3 (p = 0.01), and the area under pH 6.2 was higher for the animals fed T3 and T5 (p < 0.01) when compared to animals receiving T2. There is no substantial improvement on the rumen fermentation parameters by the concurrent utilization of MON and VM molecules, where the higher starch and protein degradability did not improve the rumen fermentation.

Effect of probiotics and acidifiers on feed intake, egg mass, production performance, and egg yolk chemical composition in late-laying quails.

Background and Aim: Probiotics can be used as an alternative to antibiotic growth promoters because antibiotics are prohibited worldwide. This study investigated the potential combination of probiotics and acidifiers to improve feed intake, productive performance, egg mass, and egg yolk chemical composition of late-laying quail for the health of humans who consume quail products. Materials and Methods: One hundred laying quails were divided into 4 × 5 treatments, with each group consisting of five replications. The adaptation period was 2 weeks, and the treatment was continued for 4 weeks. Probiotics and acidifiers were added to drinking water and incorporated into the diet. Feed and water were provided ad libitum. Treatment duration (1 week, 2 weeks, 3 weeks, and 4 weeks) and additional feed treatment (control, probiotic 2% + 0.5% acidifier, probiotic 2% + 1% acidifier, probiotic 4% + 0.5% acidifier, and probiotic 4% + 1% acidifier, respectively). Results: Significant differences (p < 0.05) were observed in feed intake, quail day production, feed efficiency, egg mass in laying quails, and the chemical composition of egg yolk with probiotics and acidifiers in late-laying quails. Conclusion: The combination of probiotics and acidifiers can improve feed intake, production performance, egg mass, and egg yolk chemical composition in late-laying quails.

Toxicology and safety study of L-tryptophan and its impurities for use in swine.

L-tryptophan, an essential amino acid for physiological processes, metabolism, development, and growth of organisms, is widely utilized in animal nutrition and human health as a feed additive and nutritional supplement, respectively. Despite its known benefits, safety concerns have arisen due to an eosinophilia-myalgia syndrome (EMS) outbreak linked to L-tryptophan consumed by humans. Extensive research has established that the EMS outbreak was caused by an L-tryptophan product that contained certain impurities. Therefore, safety validations are imperative to endorse the use of L-tryptophan as a supplement or a feed additive. This study was conducted in tertiary hybrid [(Landrace × Yorkshire) × Duroc] pigs to assess general toxicity and potential risks for EMS-related symptoms associated with L-tryptophan used as a feed additive. Our investigation elucidated the relationship between L-tryptophan and EMS in swine. No mortalities or clinical signs were observed in any animals during the administration period, and the test substance did not induce toxic effects. Hematological analysis and histopathological examination revealed no changes in EMS-related parameters, such as eosinophil counts, lung lesions, skin lesions, or muscle atrophy. Furthermore, no test substance-related changes occurred in other general toxicological parameters. Through analyzing the tissues and organs of swine, most of the L-tryptophan impurities that may cause EMS were not retained. Based on these findings, we concluded that incorporating L-tryptophan and its impurities into the diet does not induce EMS in swine. Consequently, L-tryptophan may be used as a feed additive throughout all growth stages of swine without safety concerns.

Effect of dietary chitosan on the growth performance, intestinal histology and growth-related gene expression in stellate sturgeon (Acipenser stellatus) juveniles.

As sturgeon breeding has proliferated, there has been a heightened demand for growth stimulators in their diets. This study aimed to determine the impact of dietary chitosan on growth performance, whole-body proximate composition, growth-related gene expression, and intestinal histology in juvenile Acipenser stellatus. A total of 180 A. stellatus juveniles with an average weight of 31.90 ± 0.73 g were fed with diets containing 0 (control), 1.5, 3.0, 4.5, and 6.0 g chitosan.kg-1 basic diet for eight weeks. The findings revealed a significant enhancement in growth performance with rising chitosan concentrations. Furthermore, chitosan supplementation upregulated the expression of the growth hormone gene in both brain and liver tissues. In liver samples, the most pronounced expression of the insulin-like growth factor-1 gene was noted at 6.0 g chitosan.kg-1, while in brain samples, peak expressions were observed in both the 4.5 and 6.0 g chitosan.kg-1 treatments. While the whole-body proximate composition remained relatively stable, there was a notable decrease in whole-body lipids with the escalation of chitosan dosage. Intestinal villi dimensions, both height and width, were amplified in the chitosan-supplemented groups compared to controls. In summation, chitosan supplementation showed promise in bolstering growth performance, refining intestinal morphology, and enhancing growth-related gene expression. Analysis of the polynomial regression of weight gain and specific growth rate revealed that the optimum dietary chitosan requirements in A. stellatus were 5.32 and 5.21 g chitosan.kg-1, respectively.

Safety and efficacy of a feed additive consisting of inactivated selenised yeast (Saccharomyces cerevisiae CCTCC M 2022402) for all animal species (Phytobiotics Futterzusatzstoffe GmbH).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of the selenised yeast (inactivated) Saccharomyces cerevisiae CCTCC M 2022402 (Plexomin® Se 3000, available in two forms: 'granules' and 'micro') as a nutritional feed additive for all animal species. Based on a tolerance-efficacy trial, the FEEDAP Panel concluded that the additive is safe for chickens for fattening at proposed conditions of use and this conclusion can be extrapolated to all animal species. In the absence of deposition data in all animal species and products, the FEEDAP Panel cannot conclude on the safety for the consumer. Plexomin® Se 3000 (granules) is dust-free; therefore, the exposure through inhalation is unlikely. Plexomin® Se 3000 (micro) presents a risk by inhalation. Both forms of the additive (granules and micro) are considered as respiratory sensitisers. Due to the lack of data, no conclusions can be drawn on the dermal and eye irritation potential of Plexomin® Se 3000 (granules). Plexomin® Se 3000 (micro) is not irritant to the skin and the eyes. No conclusions can be drawn on the potential of both forms of the additive to be dermal sensitisers. The use of the additive in animal nutrition is considered safe for the environment. The additive is an efficacious source of selenium in feedingstuffs for all animal species.

Evaluating the effects of benzoic acid on nursery and finishing pig growth performance.

Three studies were conducted evaluating the use of benzoic acid in swine diets. In experiment 1, 350 weanling barrows (DNA 200 × 400; initially 5.9 ±â€…0.04 kg) were allotted to one of the five dietary treatments with 14 pens per treatment. Diets were fed in three phases: phase 1 from weaning to day 10, phase 2 from days 10 to 18, and phase 3 from days 18 to 38. Treatment 1 contained no benzoic acid throughout all three phases (weaning to day 42). Treatment 2 included 0.50% benzoic acid throughout all three phases. Treatment 3 contained 0.50% benzoic acid in phases 1 and 2, and 0.25% benzoic acid in phase 3. Treatment 4 contained 0.50% benzoic acid in phases 1 and 2, and no benzoic acid in phase 3. Treatment 5 contained 0.50% benzoic acid in phase 1, 0.25% benzoic acid in phase 2, and no benzoic acid in phase 3. For the overall period, pigs fed 0.50% in the first two phases and 0.25% benzoic acid in the final phase had greater (P < 0.05) average daily gain (average daily gain) than pigs fed no benzoic acid through all three phases, or pigs fed 0.50% in the first two phases and no benzoic acid in the final phase, with pigs fed the other treatments intermediate. Pigs fed 0.50% in the first two phases and 0.25% benzoic acid in the final phase had improved (P < 0.05) gain-to-feed ratio (G:F) compared with pigs fed no benzoic acid throughout all three phases, pigs fed 0.50% in the first two phases and no benzoic acid in the third phase, or pigs fed 0.50%, 0.25%, and no benzoic acid, respectively. For experiment 2, a 101-d trial was conducted using two groups of 1,053 finishing pigs (2,106 total pigs; PIC 337 × 1,050; initially 33.3 ±â€…1.9 kg). Dietary treatments were corn-soybean meal-dried distillers grains with solubles-based with the addition of none, 0.25%, or 0.50% benzoic acid. Overall, pigs fed increasing benzoic acid had a tendency for increased average daily feed intake (linear, P = 0.083) but decreased G:F (linear, P < 0.05). In experiment 3, 2,162 finishing pigs (DNA 600 × PIC 1050; initially 31.4 ±â€…2.2 kg) were used in a 109-d trial. Dietary treatments were formulated with or without 0.25% benzoic acid. For the overall experimental period, pigs fed benzoic acid had increased (P < 0.05) G:F. In summary, feeding benzoic acid elicits improved growth performance when fed throughout the entire nursery period while improved G:F in growing-finishing pigs was observed in one experiment, but not in the other.

Turning weeds into feed: Ensiling Calotropis gigantea (Giant milkweed) reduces its toxicity and enhances its palatability for dairy cows.

Calotropis gigantea (Giant milkweed, GM) has the potential to be utilized as a new feed additive for ruminants, however, the presence of unpalatable or toxic compounds decreases animal feed intake. This study aimed to valorize GM as a potential new feed resource through the chemical and microbial biotransformation of toxic compounds that will henceforth, make the plant palatable for cows. After GM's ensiling using fermentative bacteria, the plant was sampled for UHPLC-MS/MS to analyse the metabolomic changes. Illumina Miseq of the 16 S rRNA fragment genes and ITS1 were used to describe the microbial composition and structure colonizing GM silage and contributing to the biodegradation of toxic compounds. Microbial functions were predicted from metataxonomic data and KEGG pathways analysis. Eight Holstein dairy cows assigned in a cross-over design were supplemented with GM and GM silage to evaluate palatability and effects on milk yield and milk protein. Cows were fed their typical diet prior to the experiment (positive control). After ensiling, 23 flavonoids, 47 amino acids and derivatives increased, while the other 14 flavonoids, 9 amino acids and derivatives decreased, indicating active metabolism during the GM ensiling process. Lactobacillus buchneri, Bacteroides ovatus, and Megasphaera elsdenii were specific to ensiled GM and correlated to functional plant metabolites, while Sphingomonas paucimobilis and Staphylococcus saprophyticus were specific to non-ensiled GM and correlated to the toxic metabolite 5-hydroxymethylfurfural."Xenobiotics biodegradation and metabolism", "cancer overview" and "neurodegenerative disease" were the highly expressed microbial KEGG pathways in non-ensiled GM. Non-ensiled GM is unpalatable for cows and drastically reduces the animal's feed intake, whereas ensiled GM does not reduce feed intake, milk yield and milk protein. This study provides essential information for sustainable animal production by valorizing GM as a new feed additive.

Impact of Hydroxytyrosol-Rich Extract Supplementation in a High-Fat Diet on Gilthead Sea Bream (Sparus aurata) Lipid Metabolism.

High-fat diets (HFDs) enhance fish growth by optimizing nutrient utilization (i.e., protein-sparing effect); however, their potential negative effects have also encouraged the search for feed additives. This work has investigated the effects of an extract rich in a polyphenolic antioxidant, hydroxytyrosol (HT), supplemented (0.52 g HT/kg feed) in a HFD (24% lipid) in gilthead sea bream (Sparus aurata). Fish received the diet at two ration levels, standard (3% of total fish weight) or restricted (40% reduction) for 8 weeks. Animals fed the supplemented diet at a standard ration had the lowest levels of plasma free fatty acids (4.28 ± 0.23 mg/dL versus 6.42 ± 0.47 in the non-supplemented group) and downregulated hepatic mRNA levels of lipid metabolism markers (ppara, pparb, lpl, fatp1, fabp1, acox1, lipe and lipa), supporting potential fat-lowering properties of this compound in the liver. Moreover, the same animals showed increased muscle lipid content and peroxidation (1.58- and 1.22-fold, respectively, compared to the fish without HT), suggesting the modulation of body adiposity distribution and an enhanced lipid oxidation rate in that tissue. Our findings emphasize the importance of considering this phytocompound as an optimal additive in HFDs for gilthead sea bream to improve overall fish health and condition.

Dietary Artemisia arborescens Supplementation Effects on Growth, Oxidative Status, and Immunity of Gilthead Seabream (Sparus aurata L.).

Fish infectious diseases are one of the main constraints of the aquaculture sector. The use of medicinal plants provides a sustainable way of protection using safe, eco-friendly compounds in a more cost-effective way of treatment, compared to antibiotics. The aim of the present study is the assessment of Artemisia arborescens (AA) feed-supplementation effects on gilthead seabream (Sparus aurata). Fish with an average initial body weight of 109.43 ± 3.81 g, were divided into two groups based on AA feed composition (A25 and A50). Following two months of ad libitum feeding, the effect of diets on fish weight and length were measured. Fish serum and mucus were analyzed for non-specific immune parameters (nitric oxide, lysozyme, myeloperoxidase, protease-/anti-protease activity, and complement), antibody responses, oxidative stress (cytochrome P450 1A1, metallothionein), and metabolism markers (total protein, alkaline phosphatase, and glucose). Expression levels of antioxidants (sod1, gpx1), cytokines (il-1b, il-10, tfgb1, and tnfa), hepcidin, and heat shock protein grp75 genes were measured in spleen samples. A results analysis indicated that A. arborescens use as a feed supplement has a compromised positive effect on the growth performance, immune response, and blood parameters of gilthead seabream. Overall, the suitability of A. arborescens as an efficient food supplement for gilthead seabream health improvement was investigated, setting the basis for its application assessment in Mediterranean aquaculture.

Surface Engineering of Escherichia coli to Display Its Phytase (AppA) and Functional Analysis of Enzyme Activities.

Escherichia coli phytase (AppA) is widely used as an exogenous enzyme in monogastric animal feed mainly because of its ability to degrade phytic acid or its salt (phytate), a natural source of phosphorus. Currently, successful recombinant production of soluble AppA has been achieved by gene overexpression using both bacterial and yeast systems. However, some methods for the biomembrane immobilization of phytases (including AppA), such as surface display on yeast cells and bacterial spores, have been investigated to avoid expensive enzyme purification processes. This study explored a homologous protein production approach for displaying AppA on the cell surface of E. coli by engineering its outer membrane (OM) for extracellular expression. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of total bacterial lysates and immunofluorescence microscopy of non-permeabilized cells revealed protein expression, whereas activity assays using whole cells or OM fractions indicated functional enzyme display, as evidenced by consistent hydrolytic rates on typical substrates (i.e., p-nitrophenyl phosphate and phytic acid). Furthermore, the in vitro results obtained using a simple method to simulate the gastrointestinal tract of poultry suggest that the whole-cell biocatalyst has potential as a feed additive. Overall, our findings support the notion that biomembrane-immobilized enzymes are reliable for the hydrolysis of poorly digestible substrates relevant to animal nutrition.

Effects of Shrimp Shell-Derived Chitosan on Growth, Immunity, Intestinal Morphology, and Gene Expression of Nile Tilapia (Oreochromis niloticus) Reared in a Biofloc System.

Chitosan (CH) shows great potential as an immunostimulatory feed additive in aquaculture. This study evaluates the effects of varying dietary CH levels on the growth, immunity, intestinal morphology, and antioxidant status of Nile tilapia (Oreochromis niloticus) reared in a biofloc system. Tilapia fingerlings (mean weight 13.54 ± 0.05 g) were fed diets supplemented with 0 (CH0), 5 (CH5), 10 (CH10), 20 (CH20), and 40 (CH40) mL·kg-1 of CH for 8 weeks. Parameters were assessed after 4 and 8 weeks. Their final weight was not affected by CH supplementation, but CH at 10 mL·kg-1 significantly improved weight gain (WG) and specific growth rate (SGR) compared to the control (p < 0.05) at 8 weeks. Skin mucus lysozyme and peroxidase activities were lower in the chitosan-treated groups at weeks 4 and 8. Intestinal villi length and width were enhanced by 10 and 20 mL·kg-1 CH compared to the control. However, 40 mL·kg-1 CH caused detrimental impacts on the villi and muscular layer. CH supplementation, especially 5-10 mL·kg-1, increased liver and intestinal expressions of interleukin 1 (IL-1), interleukin 8 (IL-8), LPS-binding protein (LBP), glutathione reductase (GSR), glutathione peroxidase (GPX), and glutathione S-transferase (GST-α) compared to the control group. Overall, dietary CH at 10 mL·kg-1 can effectively promote growth, intestinal morphology, innate immunity, and antioxidant capacity in Nile tilapia fingerlings reared in biofloc systems.

Optimization of solvent and extraction time on secondary metabolite content of mangosteen leaf (Garcinia mangostana L.) as a feed additive candidate on poultry.

Objectives: This research aimed to determine the optimum type of solvent and extraction time to produce secondary metabolites (phenolics, flavonoids, tannins, and antioxidants) from mangosteen leaves (Garcinia mangostana L.) as feed additive candidates for poultry. Materials and Methods: This research used a completely randomized design with a 2 × 5 factorial design with three replications. Factor A used two types of distilled water as a solvent (ordinary distilled water and distilled water heated at 100°C), while Factor B encompassed various extraction times (15, 30, 45, 60, and 75 min). The parameters assessed included total phenolic content (TPC), total flavonoid content (TFC), total tannin content (TTC), and overall antioxidant activity. Results: The TPC, TFC, TTC, and total antioxidant activity all showed a highly significant interaction (p < 0.01) with the type of solvent and extraction duration. Conclusion: The best solvent and time for mangosteen leaf extract to produce secondary metabolites, which can be candidates for feed additives in poultry, is ordinary distilled water for 45 min. In this research, the phenol content was 81.03%, flavonoids 11.07%, tannins 1.01%, and antioxidants 77.61%.

Use of red grape pomace and Aloe vera gel as nutraceuticals to ameliorate stocking density-induced stress in commercial male broilers.

The combined effect of Aloe vera gel (AVG) administered through drinking water and dietary red grape pomace powder (RGP) on growth performance, physiological traits, welfare indicators, and meat quality in densely stocked broilers was evaluated. A total of 750, two-week-old male Ross 308 broilers (317.7 ± 10.12 g live weight) were randomly assigned to 25 cages, with each cage as an experimental unit. The broilers were stocked at a density of 30 birds per cage with a floor space of 1.32 m2. Dietary treatments were a standard grower or finisher diet (CON); CON containing 30 g RGP /kg diet plus either 1 (GPA1), 2 (GPA2), 3 (GPA3), or 4% (GPA4) AVG in drinking water. Treatment GPA1 promoted higher (P < 0.05) overall weight gain and overall feed conversion ratio (FCR) than CON. Positive quadratic effects (P < 0.05) were noted for mean corpuscular hemoglobin, basophils, 24-hour breast meat yellowness, chroma, and hue angle. The GPA2 group had the lowest (P < 0.05) gait score while the CON group had the highest score. Concurrent supplementation with a 30 g RGP /kg diet plus 1% AVG in drinking water enhanced weight gain, FCR, and finisher weight of densely stocked broilers. However, AVG doses beyond 1% did not enhance performance and physiological traits in densely stocked broilers.

Novel oxidising feed additives reduce in vitro methane emissions using the rumen simulation technique.

Enteric methane (CH4) produced by ruminant livestock is a potent greenhouse gas and represents significant energy loss for the animal. The novel application of oxidising compounds as antimethanogenic agents with future potential to be included in ruminant feeds, was assessed across two separate experiments in this study. Low concentrations of oxidising agents, namely urea hydrogen peroxide (UHP) with and without potassium iodide (KI), and magnesium peroxide (MgO2), were investigated for their effects on CH4 production, total gas production (TGP), volatile fatty acid (VFA) profiles, and nutrient disappearance in vitro using the rumen simulation technique. In both experiments, the in vitro diet consisted of 50:50 grass silage:concentrate on a dry matter basis. Treatment concentrations were based on the amount of oxygen delivered and expressed in terms of fold concentration. In Experiment 1, four treatments were tested (Control, 1× UHP + KI, 1× UHP, and 0.5× UHP + KI), and six treatments were assessed in Experiment 2 (Control, 0.5× UHP + KI, 0.5× UHP, 0.25× UHP + KI, 0.25× UHP, and 0.12× MgO2). All treatments in this study had a reducing effect on CH4 parameters. A dose-dependent reduction of TGP and CH4 parameters was observed, where treatments delivering higher levels of oxygen resulted in greater CH4 suppression. 1× UHP + KI reduced TGP by 28 % (p = 0.611), CH4% by 64 % (p = 0.075) and CH4 mmol/g digestible organic matter by 71 % (p = 0.037). 0.12× MgO2 reduced CH4 volume by 25 % (p > 0.05) without affecting any other parameters. Acetate-to-propionate ratios were reduced by treatments in both experiments (p < 0.01). Molar proportions of acetate and butyrate were reduced, while propionate and valerate were increased in UHP treatments. High concentrations of UHP affected the degradation of neutral detergent fibre in the forage substrate. Future in vitro work should investigate alternative slow-release oxygen sources aimed at prolonging CH4 suppression.