The impact of Codonopsis Pilosulae and Astragalus Membranaceus extract on growth performance, immunity function, antioxidant capacity and intestinal development of weaned piglets.

Introduction: The objective of this study was to examine the impact of Codonopsis pilosula and Astragalus membranaceus extract (CA) on the growth performance, diarrhea rate, immune function, antioxidant capacity, gut microbiota, and short-chain fatty acids (SCFAs) in weaned piglets. Methods: A total of forty-eight 31-day-old weaned piglets, were divided into four groups randomly based on the treatment type: control group (CON), low dose group (LCA, 0.5% CA), medium dose group (MCA, 1.0% CA), and high dose group (HCA, 1.5% CA), and were fed for a duration of 28 days. On the morning of the 1st and 29th day, the piglets were assessed by weighing them on an empty stomach, recording their daily feed intake and diarrhea rate. Results: CA increased the average daily weight gain and reduced F/G without significant differences, and the diarrhea rate was reduced in the LCA and MCA groups. Furthermore, the levels of T-AOC, SOD, GSH-Px, and MDA were increased. The levels of T-AOC in the LCA group and the MCA group, SOD in the MCA group, and GSH-Px in the HCA group were significantly higher compared with the CON group (p < 0.05). Additionally, CA significantly increased IgM, IgG, and IgA levels (p < 0.05). The results of gut microbiota analysis showed that the bacterial population and diversity of faeces were changed with the addition of CA to basal diets. CA increased the abundance of the beneficial bacterial Firmicutes and Lactobacillus. Additionally, Compared with the CON group, CA significantly increased the SCFAs content of weaned piglets (p < 0.05). Discussion: CA can alleviate oxidative stress, improve immunity and antioxidant capacity, increase the abundance of beneficial bacteria, and the content of SCFAs for improving the intestinal barrier of piglets, thus promoting growth and reducing diarrhea rate in weaned piglets.

Improvement of sea buckthorn (Hippophae rhamnoides L.) flavonoids on the antioxidant and immune performance of Yellow River carp (Cyprinus carpio L.) fed high-carbohydrate diet.

High-carbohydrate (HC) diets may lead to the deterioration of the antioxidant and immune properties of Yellow River carp and the healthy development of the industry. Studies in mammals have found that sea buckthorn flavonoids (SF) improve antioxidant and immune performance. Therefore, this study comprehensively evaluated the effects of SF on Yellow River carp using in vitro and feeding trials with an HC diet. Control (C, 27.23 %), high-carbohydrate (HC, 42.99 %), and HC + SF (0.1 %, 0.2 %, and 0.4 %) groups were studied in a 10-week aquaculture experiment. The main findings were as follows: (1) SF scavenged O2·-, ·OH, and DPPH free radicals in vitro, which gradually increased with the SF concentration. (2) The antioxidant and immune performance of Yellow River carp was enhanced by dietary supplementation with SF, which involved the regulation of activities of antioxidant and immune enzymes, as well as their changes at the transcription and protein levels. In terms of antioxidant properties, compared to the HC group, HC + SF significantly decreased the activities of glutamic-oxaloacetic transaminase and glutamic-pyruvic transaminase and the contents of H2O2 and malondialdehyde in the serum and hepatopancreas. The activities of glutathione, glutathione-Px, superoxide dismutase, catalase, and total antioxidant activity in the HC-diet group. In contrast, the addition of SF increased antioxidant enzyme activity. In the hepatopancreas and muscles, SF regulated and activated Nrf2-Keap1, a key signaling pathway for oxidative stress. SF significantly increased the mRNA expression levels of downstream genes (gr, ho-1, cat, and sod) regulated by nrf2. In terms of immune performance, 0.4 % SF markedly increased the activity of immune-related enzymes. SF inhibited the gene expression of pro-inflammatory factors induced by the HC diet and promoted the gene expression of anti-inflammatory factors. In addition, the resistance of Yellow River carp to Aeromonas hydrophila was enhanced by SF. In summary, SF supplementation can reduce oxidative stress and inflammatory harm caused by the HC diet and improve the antioxidant and immune performance of Yellow River carp to varying degrees.

Effects of fulvic acid on broiler performance, blood biochemistry, and intestinal microflora.

To study the effects of mineral fulvic acid (FuA) on broiler performance, slaughter performance, blood biochemistry index, antioxidant function, immune performance, and intestinal microflora, 360 Arbor Acres (AA) broiler chickens with similar body weights were randomly divided into 5 groups with 6 replicates in each group and 12 chickens in each replicate in the current study. Chickens in the control group (C) were fed with the basal diet, and chickens in the test groups (I, II, III, and IV) were fed with the diet supplemented with 0.05%, 0.1%, 0.2%, and 0.3% mineral FuA, respectively. The indicators were measured on the hatching day, d 21 and d 35. From the whole experimental period, FuA supplement significantly increased average body weight (ABW) (P < 0.05), average daily gain (ADG) of broilers (P < 0.05), and thymus weight (P < 0.05) in II and IV groups, but bascially reduced the pH value of thigh meat. FuA supplement significantly improved aspartate aminotransferase (AST) activity in the group III on d 35 (P < 0.05) and the serum levels of IgA and IgG on d 21 and d 35 (P < 0.05), but reduced glutathione peroxidase (GSH-Px) level on d 21 (P < 0.05) and malondialdehyde (MDA) level in serum on d 35 (P < 0.05). FuA supplement significantly affected the abundance of Barnesiella, Lachnospiraceae, Alistipes, Lactobacillus, and Christensenellaceae on genus level. Differences between group III and other groups were significant in the genera microflora composition on d 21 and d 35. Functional analysis showed that the cecum microbiota were mainly enriched in carbohydrate metabolism, amino acid metabolism, and energy metabolism. In conclusion, FuA may potentially have significant positive effects on the growth performance and immune function of AA chickens through the modulation of the gut microbiota, and the 0.1% FuA was the best in broiler diet based on the present study.

Metformin exposure altered intestinal microbiota composition and metabolites in amphibian larvae.

The antidiabetic pharmaceutical metformin (MET) is largely unmetabolized by the human body. Its residues are readily detectable in various aquatic environments and may have adverse impacts on the growth and survival of aquatic species. To date, its toxicological effects have scarcely been explored in non-fish species. Here, we exposed the tadpoles of black-spotted pond frog (Pelophylax nigromaculatus) to different concentrations (0, 1, 10 and 100 µg/L) of MET for 30 days and measured the body size, intestinal microbiota and metabolites to evaluate potential effects of MET exposure in amphibian larvae. MET exposure did not affect the growth and intestinal microbial diversity of tadpoles. However, intestinal microbial composition changed significantly, with some pathogenic bacteria (e.g., bacterial genera Salmonella, Comamonas, Stenotrophomonas, Trichococcus) increasing and some beneficial bacteria (e.g., Blautia, Prevotella) decreasing in MET-exposed tadpoles. The levels of some intestinal metabolites associated with growth and immune performance also changed significantly following MET exposure. Overall, our results indicated that exposure to MET, even at environmentally relevant concentrations, would cause intestinal microbiota dysbiosis and metabolite alteration, thereby influencing the health status of non-target aquatic organisms, such as amphibians.

Yeast culture supplementation of sow diets regulates the immune performance of their weaned piglets under lipopolysaccharide stress.

The aim of this study was to investigate the effect of dietary supplementation of sows with yeast cultures (XPC) during late gestation and lactation on the immune performance of their weaned offspring under lipopolysaccharide (LPS) stress. A total of 40 Landrace × Yorkshire sows (parity 3 to 7) with similar backfat thickness were selected and randomly divided into two treatment groups: a control group (basal diet) and a yeast culture group (basal diet + 2.0 g/kg XPC). The trial was conducted from day 90 of gestation to day 21 of lactation. At the end of the experiment, 12 piglets with similar weights were selected from each group and slaughtered 4 h after intraperitoneal injection with either saline or LPS. The results showed that the concentrations of interleukin-6 (IL-6) in the thymus and tumor necrosis factor-α in the liver increased significantly (P < 0.05) in weaned piglets after LPS injection. Maternal dietary supplementation with XPC significantly reduced the concentration of inflammatory factors in the plasma and thymus of weaned piglets (P < 0.05). LPS injection significantly upregulated the expression of some tissue inflammation-related genes, significantly downregulated the expression of intestinal tight junction-related genes, and significantly elevated the protein expression of liver phospho-nuclear factor kappa B (p-NF-κB), the phospho-inhibitory subunit of NF-κB (p-IκBα), phospho-c-Jun N-terminal kinase (p-JNK), Nuclear factor kappa-B (NF-κB), and the inhibitory subunit of NF-κB (IκBα) in weaned piglets (P < 0.05). Maternal dietary supplementation with XPC significantly downregulated the gene expression of IL-6 and interleukin-10 (IL-10) in the thymus and decreased the protein expression of c-Jun N-terminal kinase (JNK) in the liver of weaned piglets (P < 0.05). In summary, injection of LPS induced an inflammatory response in weaned piglets and destroyed the intestinal barrier. Maternal dietary supplementation of XPC improved the immune performance of weaned piglets by inhibiting inflammatory responses.

Weaning older, more mature pigs helps prevent many of the adverse gastrointestinal effects associated with weaning stress, and maternal nutritional interventions can influence offspring gut health and growth performance. Therefore, it is important to explore the effects of maternal nutritional interventions on their offspring. Yeast cultures are a class of biological products consisting of metabolites produced during the anaerobic fermentation of yeast and some live yeast cells, and function to maintain the intestinal health of animals and improve production performance. The effect of sow dietary supplementation with yeast cultures on the immune performance of their weaned offspring under lipopolysaccharide stress has not so far been reported. This study provided a basis for understanding the effects of maternal transfer of yeast cultures to their offspring and provided data to support the application of yeast cultures in actual production.

Applications and prospects of functional oligosaccharides in pig nutrition: A review.

Oligosaccharides are low molecular weight carbohydrates between monosaccharides and polysaccharides, which consist of 2 to 20 monosaccharides linked by glycosidic bonds. They have the effects of promoting growth, regulating immunity, improving the structure of intestinal flora, and are anti-inflammatory and antioxidant. With the comprehensive implementation of the antibiotic prohibition policy in China, oligosaccharides as new green feed additive have been paid more attention. Oligosaccharides can be divided into the following 2 categories according to their digestive characteristics: one is easy to be absorbed by the intestine, called common oligosaccharides, such as sucrose and maltose oligosaccharide; the other is difficult to be absorbed by the intestine and has special physiological functions, called functional oligosaccharides. The common functional oligosaccharides include mannan oligosaccharides (MOS), fructo-oligosaccharides (FOS), chitosan oligosaccharides (COS), xylo-oligosaccharides (XOS) and so on. In this paper, we review the types and sources of functional oligosaccharides, their application in pig nutrition, and the factors limiting their efficacy in recent years. This review provides the theoretical basis for further research of functional oligosaccharides, and the future application of alternative antibiotics in pig industry.

Effect of microencapsulation of egg yolk immunoglobulin Y by sodium alginate/chitosan/sodium alginate on the growth performance, serum parameters, and intestinal health of broiler chickens.

OBJECTIVE: Egg yolk immunoglobulin (IgY) is an antibiotic alternative to prevent and fight intestinal pathogenic infections. This study aimed to investigate the effects of sodium alginate/chitosan/sodium alginate IgY microcapsules on the growth performance, serum parameters, and intestinal health of broiler chickens. METHODS: One-day-old broilers (Ross 308) were divided into five treatments, each with 10 replicates of five chickens. The dietary treatments were maintained for 28 days and consisted of a basal diet (NC), basal diet + 500 mg chlortetracycline/kg diet (CH), basal diet + 50 mg non-microencapsulated IgY/kg diet (NM), basal diet + 600 mg low levels microencapsulated IgY/kg diet (LM), and basal diet + 700 mg high levels microencapsulated IgY/kg diet (HM). RESULTS: Throughout the 28-day trial period, the NM, LM, HM, and CH groups increased average daily gain compared with the NC group (p<0.05), and the HM group reduced feed conversion ratio compared with the CH group (p<0.05). The LM and HM groups increased relative organ weights of thymus and spleen compared with the CH and NM groups (p<0.05). The HM group improved the duodenal, jejunal and ileum villi height (VH) and villus height to crypt depth ratio (VH:CD) compared with the CH and NM groups (p<0.05). Compared with the CH group, the HM group increased serum immunoglobulin (IgA), immunoglobulin G (IgG), superoxide dismutase, total antioxidant capacity, and glutathione peroxidase levels (p<0.05), and decreased serum malondialdehyde levels (p<0.05). Compared with the NC group, the NM, LM, HM, and CH groups reduced colonic Escherichia coli and Salmonella levels (p<0.05). and the HM group promoted the levels of lactic acid bacteria and bifidobacteria compared with the CH group (p<0.05). CONCLUSION: Microencapsulation could be considered as a way to improve the efficiency of IgY. The 700 mg high levels microencapsulated IgY/kg diet could potentially be used as an alternative to antibiotics to improve the immune performance and intestinal health, leading to better performance of broiler chickens.

Effects of ß-alanine on intestinal development and immune performance of weaned piglets.

Beta-alanine is an important amino acid involved in several metabolic reactions in the body. The study aimed to investigate the effect of ß-alanine supplementation on intestinal development and the immune performance of weaned piglets. Thirty-two 21-day-old healthy weaned piglets (half female and half male; Duroc × Landrace × Yorkshire) with an initial body weight of 8.11 ± 0.21 kg were randomly divided into 4 groups with 8 replicates of 1 pig each. The control group was fed a basal diet and the three experimental treatment groups were fed diets supplemented with 300, 600 and 1,200 mg/kg ß-alanine, respectively. The trial lasted 28 days and the diets fed were divided into 2 phases: the late lactation period (day 1 to 14) and the nursery period (day 15 to 28), during which the weaned piglets had free access to food and water. The regulatory effects of ß-alanine were further investigated in vitro using organoids obtained from the jejunum of piglets. In vivo, the addition of ß-alanine to the diet had no significant effect on the growth performance of weaned piglets (P > 0.05), but significantly reduced serum levels of immunoglobulin G (IgG) (P < 0.01), immunoglobulin M (IgM) (P = 0.005), and complement 3 (C3) (P = 0.017). The serum interleukin- 6 (IL-6) levels (P < 0.01) were significantly reduced in the 1,200 mg/kg treatment group. The addition of ß-alanine increased ileal villus height, with the most significant effect at a concentration of 300 mg/kg (P = 0.041). The addition of 600 mg/kg ß-alanine significantly up-regulated the expression of superoxide dismutase (SOD) activity (P = 0.020) and the zonula occludens-1 (ZO-1) gene (P = 0.049) in the jejunum. Diets supplemented with 300 mg/kg ß-alanine significantly increased the number of Ki67 positive cells in the jejunal crypts (P < 0.01). In vitro, ß-alanine increased the organoid budding rates (P = 0.001) and the budding height of the crypt significantly (P = 0.004). In conclusion, ß-alanine can improve intestinal morphology and barrier function, reduce inflammatory responses and alleviate the adverse effects of weaning stress on piglet intestinal health.

Effects of Astragalus, Epimedium, and Fructus Ligustri Lucidi extractive on antioxidant capacity, production performance, and immune mechanism of breeding pigeons under stress.

With the large-scale and intensive development of pigeon breeding industry and the improvement of production level, stress factors have an important impact on the immune, antioxidant capacity, and productivity of pigeons. In this study, the extenuating effect of Astragalus, Epimedium, and Ligustrum lucidum (AEF) on the antioxidant, production performance, and immune mechanism was investigated in breeding pigeons. Eighty pairs of 11-month-old healthy breeding pigeons with the same egg production batch were randomly divided into 4 groups: control group (C group), treated with AEF (AEF group), in restraint stress (S group) and treated with AEF and in restraint stress (S+AEF group). Results showed that AEF reduces weight loss during lactation and increases spleen weight, increased IgA, IgG, T4, GSH-Px, and SOD in serum and decreased T3 and MDA (P < 0.05). Furthermore, treatment with AEF declined HSP60, HSP70, HSP90, GR levels in liver and cFOS, GR mRNA levels in the Hypothalamus, GR mRNA levels in the pituitary (P < 0.05). Meanwhile, the results of the intestine studies showed that AEF promoted relative abundances of Firmicutes and relieve intestinal injury in the colon of pigeons. These results indicated AEF enhanced stress resistance, immunity, production performance and antioxidant capacity of pigeons.

Effects of betaine on growth performance, intestinal health, and immune response of goslings challenged with lipopolysaccharide.

The objective of this experiment was to investigate the effects of betaine on growth performance, serum parameters, intestinal health, and immune performance of goslings in response to lipopolysaccharide (LPS) challenge. A total of 168 healthy male 15-day-old Jiangnan White Goslings were randomly divided into 4 groups, with 6 replicates per treatment and seven goslings per replicate. A 2 × 2 factorial arrangement included 2 factors, that is, LPS challenge (injection of LPS or physiological saline) and betaine (added 0 or 0.06% betaine in diet). The results indicated that LPS challenge significantly reduced the average daily feed intake (ADFI), average daily gain (ADG), and body weight (BW) at 21 D of the goslings, while dietary betaine supplementation tended to increase the ADFI during the LPS stress period (P = 0.08) and BW at 21 D of the goslings (P = 0.09). The LPS-challenged goslings showed higher pro-inflammatory cytokines (interleukin-1 [IL-1ß], interleukin-6 [IL-6], tumor necrosis factor-α (TNF-α), and Interferon-gamma [IFN-γ]) and lower anti-inflammatory cytokine (Interleukin-10 [IL-10]) (P < 0.05) at 21 D of age. Dietary betaine supplementation alleviated LPS-induced increase in pro-inflammatory cytokines. The LPS challenge significantly decreased duodenal and jejunal villus height (VH) and villus height and crypt depth ratio (VCR), while the addition of betaine significantly increased duodenal VH and VCR (P < 0.05). On the other hand, addition of betaine significantly alleviated decline of enzyme activity on lipase, amylase, trypsin, and chymotrypsin in the intestinal of goslings. The LPS challenge significantly increased the content of serum D-lactic acid (D-LA) and the activity of diamine oxidase (DAO) at 21 D of the goslings. The LPS challenge and betaine addition significantly increased the mRNA expression of Occcludin (OCLN) in jejunal mucosa at 28 D of the goslings (P < 0.05). In conclusion, our research demonstrated that betaine can alleviate the decline of growth performance and immune performance in goslings caused by LPS. The results also indicate betaine possesses anti-inflammation properties and improves intestinal barrier functions. We recommend that 0.06% betaine be added into the diet to improve the intestinal health and immune performance of goslings.

Effects of blue-green LED lights with two perceived illuminance (human and poultry) on immune performance and skeletal development of layer chickens.

Light is one of the essential environmental factors in the production process of laying hens, which can directly affect their behavior, growth and development, and production performance. The spectral sensitivity of humans is different from that of poultry, and the perceived illuminance units of human and poultry are lux and clux, respectively. If the light management of laying hen production is carried out according to human perceived illuminance, the growth and development of laying hens during pullet rearing may be adversely affected due to the discomfort of the perceived illuminance. Preliminary research has found that blue-green LED light can improve the immune function of laying hens during the brooding and rearing periods. However, the differences of the effects caused by blue-green light on the immune performance and bone development of laying hens during pullet rearing are still unclear for the 2 spectral sensitivities. A total of 120 Jinghong layer chickens were raised from 1 d to 13 wk of age in one of three groups with a white LED light (light intensity unit lux, WL) group, a blue-green LED light (light intensity unit lux, HBGL) group, and blue-green LED light (light intensity unit clux, PBGL) group, and unlimited feed and water were provided during the whole experiment. At 7 and 13 wk of age, the immune performance, bone parameters, and related gene expression were investigated. The results showed that compared with the WL groups, HBGL and PBGL increased the immunoglobulin A (IgA) content at 13 wk of age and the IgM content at 7 wk of age (P < 0.05). The bone mineral density (BMD) at 7 and 13 wk of age and tibial strength (TS) at 13 wk of age of the pullets in the WL group were significantly higher than those in the HBGL and PBGL group (P < 0.05). Osteoclastogenesis inhibitory factor gene (OPG mRNA) expression was increased in the layer chickens at the age of 7 and 13 wk for the WL group (P < 0.05). Compared with the WL group and PBGL group, the melanopsin gene (OPN4 mRNA) transcription level of hypothalamus and pineal gland of the chickens under HBGL significantly increased at 7 and 13 wk of age (P < 0.05). In conclusion, blue-green LED light with two perceived illuminance (human and poultry) can increase the Ig content and the immune performance of layer chickens, and blue-green LED light (light intensity unit lux) can promote the expression of OPN4 gene in the hypothalamus and pineal gland. In addition, white LED light can enhance bone quality by increasing tibia OPG gene expression.

Dietary Hermetia illucens Larvae Replacement Alleviates Diarrhea and Improves Intestinal Barrier Function in Weaned Piglets Challenged With Enterotoxigenic Escherichia coli K88.

A high-quality protein substitute, Hermetia illucens (black soldier fly) larvae powder, is rich in protein and often used in animal feed. This study aimed to investigate the feasibility and optimal ratio of replacing fish meal with H. illucens larvae in weaned piglets and to demonstrate the effects on piglets' growth performance, intestinal microflora and immune performance. Forty-eight female weaned piglets were randomly classified into three groups. Each group consisted of eight pens (replicates), with two piglets per pen. Three groups containing different proportions of H. illucens larvae (0, 4, and 8%) were referred to as C, HI4, and HI8. We first designed a 28-day feeding experiment to detect growth performance; after that, the piglets were induced with oral gavage of enterotoxigenic Escherichia coli K88 (ETEC K88) and recording diarrhea on day 29 of the experiment. Samples were taken on the 32nd day to detect the effect of H. illucens larvae on the immune performance of the weaned piglets. H. illucens larvae replacement did not cause any obvious change in the growth performance nether in HI4 nor in HI8 of weaned piglets with 28 d feeding stage. H. illucens larvae could improve the intestinal health of weaned piglets by increasing the content of Lactobacillus and reducing the content of Streptococcus. Compared with C+K88 group, the diarrhea rate was attenuated for the H. illucens supplemented group. The integrity of ileum villi in HI4+K88 and HI8+K88 groups was better than that in C+K88 group, and the villi in C+K88 group were severely damaged. The expression of IL-10, Occludin and Claudin-3 in the intestinal mucosa of the HI4+K88 group and HI8+K88 group were significantly increased (P < 0.05), and the expression of TNF-α was significantly decreased (P < 0.05) compared with the C+K88 group. The results of immunoblotting also validated that the same ETEC K88 treatment of weaned piglets enhanced the expression of tight junction protein in the intestinal mucosa of the H. illucens addition group. ETEC-induced diarrhea will be reduced by the diet of weaned piglets containing H. illucens larvae, ameliorating the immune performance of piglets. Our results indicates that the optimal dosage of H. illucens replacement in weaned piglets is 4%.

Effects of vitamin A supplementation in the diet of breeding geese on offspring intestinal tissue morphology and immune performance.

OBJECTIVE: The effects of maternal and offspring dietary vitamin A (VA) supplementation on early body weight, digestive tract function and immune function in goslings were studied. METHODS: Yangzhou geese (180 d old) were randomly divided into 5 experimental groups of 15 females and 3 males (the males were kept until slaughter). Eggs were collected for hatching during the peak laying period. A total of 96 goslings were selected from each treatment group (each fed a basic diet supplemented with 0, 4,000, 8,000, 12,000 or 16,000 IU/kg VA) and randomly divided into 2 groups, with 6 replicates in each group and 8 goslings in each replicate. The gosling diet was supplemented with 0 or 9,000 IU/kg VA. RESULTS: i) Villus length, villus width and the muscle thickness of the duodenum, jejunum and ileum were increased and the crypt depth was reduced after adding 12,000 IU/kg VA to the goslings' diet (p<0.05). Adding 9,000 IU/kg VA to the offspring diet increased the length of the duodenal villi and width of the ileum and decreased the crypt depth of the ileum (p<0.05). ii) Supplementing the maternal diet with 12,000 IU/kg VA increased immune organ weight, the immune organ index and immunoglobulin content in goslings (p<0.05). The bursa weight and immunoglobulin G content of offspring were higher in the 9,000 IU/kg VA supplementation group than in the group with no supplementation (p<0.05). CONCLUSION: Offspring growth and development were affected by the amount of VA added into maternal diet. The negative effect of maternal VA deficiency on offspring can be compensated by adding VA to the offspring diet. Continued VA supplementation in the offspring diet after excessive VA supplementation in the maternal diet is unfavorable for gosling growth and development.

Protective role of dryland rearing on netting floors against mortality through gut microbiota-associated immune performance in Shaoxing ducks.

Dryland rearing on netting floors (DRNF) is a new rearing method for ducks, which could prevent duck excreta from polluting water bodies. However, the influence of DRNF on duck production and immune performance remains poorly understood. In this study, 2,280 Shaoxing ducks, an egg-type breed of Sheldrake in China, were chosen and randomly divided into 2 groups to investigate the effects of DRNF on duck farming. During the experimental laying rates, feed-egg ratios, and mortality rates of the 2 groups were calculated and recorded. Serum immune parameters, including thymus index, spleen index, levels of immunoglobulin G (IgG), interleukin 1ß (IL-1ß), and tumor necrosis factor α (TNF-α), were determined. Sequencing of the 16S rRNA gene was used to analyze the variability of gut microbiota in the duck ileum and cecum. The results showed that DRNF significantly reduced the mortality rate of the ducks and increased the thymus index (P < 0.05), compared to the control. No other significant differences were detected in productional and immune indices (P > 0.05). The 16S rRNA sequencing results revealed differentially enriched microbial compositions in the ileum and cecum, which might be responsible for the improved immune function of Shaoxing ducks. For example, an increase in Lactobacillaceae (family), Anaerotruncus (genus), Saccharibacteria (phylum), Flavobacteriaceae (family), and a reduction in Anaerobiospirillum (genus), Lachnospiraceae (family), Blautia (genus) was revealed in the DRNF ducks. In conclusion, DRNF could alter gut microflora, enhance duck immune system, and reduce mortality in Shaoxing ducks.