Lactobacillus acidophilus and Bacillus subtilis significantly change the growth performance, serum immunity and cecal microbiota of Cherry Valley ducks during the fattening period.

This study explored the effects of a Bacillus subtilis and Lactobacillus acidophilus mixture containing the co-fermented products of the two probiotics on growth performance, serum immunity and cecal microbiota of Cherry Valley ducks. This study included 480 one-day-old Cherry Valley ducks divided into four feeding groups: basal diet (control group) and basal diet supplemented with 300, 500, or 700 mg/kg of the probiotic powder; the ducks were raised for 42 days. Compared with the control group, body weight on day 42 and the average daily gain on days 15-42 significantly increased (p < 0.05), and the feed conversion rate significantly decreased (p < 0.05) in the experimental groups. Furthermore, the serum immunoglobulin (Ig) A, IgG, IgM, and interleukin (IL)-4 levels increased significantly (p < 0.05), and IL-1ß, IL-2, and tumor necrosis factor-α decreased significantly (p < 0.05) in the experimental groups. Finally, Sellimonas, Prevotellaceae NK3B31 group, Lachnospiraceae NK4A136 group and Butyricoccus played an important role in the cecal microbiota of the experimental group. Thus, the probiotic powder has impacts on the growth performance, serum immunity and cecal microbiota of Cherry Valley Ducks.

Dietary ethylenediamine dihydroiodide mitigated Escherichia coli O78-induced immune and intestinal damage of ducks via suppression of NF-κB signal.

This study investigated the effect of Ethylenediamine dihydroiodide (EDDI) on growth performance, immune function and intestinal health of meat ducks challenged with Avian pathogenic Escherichia coli (APEC). A total of 360 one-day-old Cherry Valley ducks with similar body weight were randomly allocated to 6 treatments (6 floor cages, 10 birds/cage). A 3 × 2 factor design was used with 3 dietary iodine levels (0, 8, 16 mg/kg in the form EDDI and whether APEC was challenged or not at 7-day-old ducks. The feeding period lasted for 20 d. The results showed that the addition of EDDI reduced APEC-induced decrease of the 20-d weight loss of meat ducks (P < 0.05), and alleviated the inflammatory response of liver tissue induced by APEC challenge in meat ducks. In terms of immune function, EDDI supplementation reduced the immune organ index and increased the immune cell count of meat ducks, reduced the level of endotoxins in the serum of meat ducks (P < 0.05), as well as inhibited the expression levels of liver and spleen inflammatory factors and TLR signaling pathway related genes induced by APEC (P < 0.05). In terms of intestinal health, EDDI inhibited APEC-induced decreases in ZO-3 genes expression and increases in IL-1ß and TNF-α expression, increased relative abundance of beneficial bacteria in the cecum and content of metabolites. Pearson correlation analysis showed that there was a significant correlation between liver inflammatory factors and TLR4 signaling pathway genes, and there might be a significant correlation between intestinal microbial flora and other physiological indexes of meat ducks, which indicated that EDDI could reduce the damage to immune function and intestinal health caused by APEC challenge through regulating the structure of intestinal flora. Collectively, our findings suggest that the EDDI can promote growth performance, improve immune function and the intestinal barrier in APEC-challenged meat ducks, which may be related to the suppression of NF-κB signal.

Polyglycerol polyricinoleate and lecithin stabilized water in oil nanoemulsions for sugaring Beijing roast duck: Preparation, stability mechanisms and color improvement.

Traditional Beijing roast duck often suffers from uneven color and high sugar content after roasting. Water-in-oil (W/O) nanoemulsion is a promising alternative to replace high concentration of sugar solution used in sugaring process according to similarity-intermiscibility theory. Herein, 3% of xylose was embedded in the aqueous phase of W/O emulsion to replace 15% maltose solution. W/O emulsions with different ratios of lecithin (LEC) and polyglycerol polyricinoleate (PGPR) were constructed by high-speed homogenization and high-pressure homogenization. Distribution and penetration extent of solutions and emulsions through the duck skin, as well as the color uniformity of Beijing roast duck were analyzed. Emulsions with LEC:PGPR ratios of 1:3 and 2:2 had better stability. Stable interfacial film and spatial structure were important factors influencing emulsion stabilization. The stable W/O emulsions could more uniformly distribute onto the surface of duck skin and longitudinally penetrate through the skin than solutions.

Effects of feeding silage of beet pulp or maize on the growth performance, meat quality, and production economics of broiler ducks.

The present study aimed to compare the growth, meat quality, and production economics of Cherry Valley broiler ducks fed with a commercial diet along with silage from beet pulp or maize. In this study, 180 male Cherry Valley ducks were reared for 49 d. The control group (group C) was fed a commercial diet ad libitum. The experimental groups were fed a restricted amount of commercial diet and ad libitum beet pulp silage (group B) or maize silage (group M). For all groups, the growth performance and meat quality were analyzed, and their production costs were estimated. The beneficial effects of feeding maize silage on the growth rate were observed on d 29 to 49 in group M; moreover, both experimental groups showed lower feed intake than group C (P < 0.05). The feed conversion ratio was lower in the first rearing stage and during the entire experimental period in groups B and M than that in group C. Group M showed a higher European Production Efficiency Factor and European Broiler Index than group C (P < 0.05). The relative weight of the liver was higher in group C than that in the experimental groups (P < 0.05). Group M showed a higher L* value of leg muscles than group C (P < 0.05). Water-holding capacity was higher in leg muscles from ducks fed with silages (P < 0.05). The experimental groups had lower costs of commercial diets. Higher costs were observed for maize silage than for beet pulp silage. Carcass sales yielded the highest profit for group M and the lowest one for group C. Compared with the control group, the silage-fed groups showed a higher estimated profit by PLN 7.94 to 10.68 per duck (P < 0.05). Based on the beneficial production results, notably lower feed conversion ratio, no negative effects on carcass characteristics, and lower production costs, especially maize or even beet pulp silage in broiler duck rearing, could be recommended.

The role of turmeric and black pepper oil nanoemulsion in attenuating cytokine storm triggered by duck hepatitis A virus type I (DHAV-I)-induced infection in ducklings.

The cytokine storm induced by duck hepatitis A virus type 1 (DHAV-1) infection significantly contributes to severe, rapid deaths and economic losses in the duck industry in Egypt. This study aimed to investigate the potential inhibitory effect of a nanoemulsion containing turmeric and black pepper oil on the immune response and pathogenesis of DHAV-1 in ducklings. A total of 105 ducklings from nonvaccinated breeders were divided into 5 experimental groups, each comprising 21 birds. The negative control group (G1) remained noninfected with DHAV-1 and nontreated with nanoemulsion, while the positive control group (G2) was infected with DHAV-1 but not treated with nanoemulsion. The other 2 groups (G3, the supplemented group which was noninfected with DHAV-1), and group 4 (the prophylactic group G4) which was infected with DHAV-1, both received nanoemulsion throughout the experiment. Group 5 (G5, the therapeutic group), on the other hand, which was infected with DHAV-1 received nanoemulsion only from the onset of clinical signs. At 5 days old, the ducklings in the positive control (G2), the prophylactic (G4), and the therapeutic group (G5) were infected with DHAV-1. All the ducklings in the infected groups exhibited depression, anorexia, and opisthotonos, and their livers displayed various degrees of ecchymotic hemorrhage, liver enlargement, and microscopic pathological lesions. Notably, the positive control group (G2) experienced the most severe and pronounced effects compared to the other infected groups treated with the nanoemulsion. Meanwhile, the viral RNA loads were lower in the liver tissues of the infected ducklings treated with the nanoemulsion (G4, and G5) compared to the positive control group G2. Additionally, the nanoemulsion effectively modulated proinflammatory cytokine expression, antioxidant enzymes, liver enzymes, and lipid profile of treated ducklings. In conclusion, the turmeric and black pepper oil nanoemulsion has the potential to be a therapeutic agent for regulating and modulating the immune response, decreasing DHAV-1-induced cytokine storms, and minimizing mortality and economic losses in the duck business. More research is needed to understand how turmeric and black pepper oil nanoemulsion alleviates DHVA-1-induced cytokine storms and lowers duckling mortality.

Evaluation of coffee husks in pellet bedding, performance characteristics, footpad dermatitis scoring, and meat quality of broiler ducks.

The study aimed to analyze the chemical composition of pellet bedding made of straw or coffee husks (10, 25, 50%) and the performance characteristics of broiler ducks and footpad dermatitis. During rearing, the properties of the bedding and utility features of ducks were analyzed, and the frequency of footpad dermatitis (FPD) in ducks was verified. There was a decrease in dry matter from the 28th day of rearing. The crude fiber, NDF, ADF, and nitrogen content decreased compared to fresh bedding, while phosphorus and potassium increased. The highest pH was found in the CH25 and CH50 groups in fresh bedding on day 42 and in CH50 on day 14. High adj. R2 was found due to rearing time and bedding material (0.817-0.985). The ducks' growth rate in the CH25 group was higher at week 6 than in the other groups. In CH10 and CH25 groups, higher carcass weight was found than in group C. In group CH10, a higher weight of pectoral muscles and lower wing proportion was found than in C. In CH25, a higher remains weight was shown than in C and CH50. In CH50, lower water-holding capacity in the pectoral muscles was found than in the other groups. Considering the bedding (the content of nitrogen, phosphorus, and potassium), carcass features, and meat quality (water-holding capacity, intramuscular fat, and water content), it is possible to use 10, 25 or 50% of coffee husks in straw pellets in the rearing of broiler ducks. Due to the FPD, the moisture should be lowered.

Effects of different dietary vitamin D combinations during the grower phase and the feed restriction phase on growth performance and sternal morphology, mineralization, and related genes expression of bone metabolism in Pekin ducks.

Our study aimed to investigate the effects of different dietary vitamin D (VD) combinations during the grower (1-32 d of age) and feed restriction (33-52 d of age) phases on growth performance. We also evaluated sternal morphology, mineralization, and related genes expression of bone metabolism as well as absorption of calcium and phosphorous in duodenal mucosa and kidney in Pekin ducks. During the grower phase, we used 2 VD regimes (Group A: 3,160 IU/kg VD3; Group B: 400 IU/kg VD3 + 69 µg/kg 25-OH-D3). Each dietary treatment had 50 replicate pens of 10 ducks per pen. During the feed restriction phase, 30 replicate pens selected from Group A and Group B, repetitively, were redivided into 5 different dietary VD regimes to form a 2 × 5 experimental design. Each group consisted of 6 replicates, each with 10 ducks. During the feed restriction phase, we evaluated 5 different dietary VD combinations were as follows: T1: 2,000 IU/kg VD3 ; T2: 5,000 IU/kg VD3; T3: 3,620 IU/kg VD3 + 34.5 µg/kg 25-OH-D3; T4: 2,240 IU/kg VD3 + 69 µg/kg 25-OH-D3; T5: 1,800 IU/kg VD3 + 80 µg/kg 25-OH-D3). Results showed that Group B combinations with T5 had a better growth performance and breast meat deposition (P < 0.1). Regardless of 5 dietary VD regimes during the feed restriction phase, Group B significantly increased (P < 0.05) 52 d sternal depth and tended to increase (P < 0.1) 52 d sternal defatted weight, ash content, and phosphate (P) content of ducks. A significant interactive effect (P < 0.05) was observed on the mRNA abundance of DMP1 and Sost1 as well as RANKL/OPG in sternum and of VDR in duodenal mucosa of ducks at 52 d of age between dietary VD combinations during 2 phases. These results indicated that dietary VD regimes during the grower phase could affect the effectiveness of dietary VD regimes during the feed restriction phases; Dietary VD combinations of both phases could affect the genes expression of bone formation and the absorption as well as reabsorption of calcium and phosphorus in duodenum and kidney.

Calcium phosphate nanoparticles conjugated with outer membrane vesicle of Riemerella anatipestifer for vaccine development in ducklings.

Biodegradable calcium phosphate nanoparticles offer a viable substitute for traditional adjuvants such as aluminum in vaccine production. Calcium phosphate nanoparticle adjuvanted with outer membrane vesicle (OMV) of gram negative bacteria may induce efficient immune response in the host. The present study was carried out to evaluate the potential of a mucosal vaccine formulation of calcium phosphate (CAP) nanoparticle using OMV of Riemerella anatipestifer (RA) as antigen against New Duck disease in ducks. The work was initiated with isolation, identification of RA, followed by OMV production and extraction. The CAP-OMV nanoparticle was prepared and characterized. The efficacy of the vaccine formulation and toxicity were studied in ducks. The average OMV yield in terms of protein concentration was found to be 122.33 ± 3.48 mg per liter of BHI broth. In SDS-PAGE, isolated OMVs exhibited presence of 16 distinct protein bands with molecular weight ranging from 142.1 to 12.1 kDa. Seven protein bands of 74.1, 69.3, 55.5, 50.6, 45.6, 25.1 and 13.1 kDa were detected relatively more distinct. The major bands detected in our findings were 42 kDa, 37 kDa and 16 kDa that corresponds to OmpA, OmpH, P6 respectively. The mean zeta size (±SD) and potential of the nanoparticle were 246.20 ± 0.53 nm and -25.60 ± 5.97 respectively. In transmission electron microscopy (TEM), the nanoparticles exhibited an average diameter of 129.80 ± 11.10 nm and displayed spherical morphology. The median protective dose (PD50) of CAP-OMV nanoparticle was 1881.10 µg of protein. Group I ducks received 3762 µg of protein (entrapped protein in CAP-OMV nanoparticle) via intra nasal route and it showed the highest serum IgG and secretory IgA level than other immunized groups. All experimental ducks were challenged with 10 × LD50 on 35 days of post primary immunization. Group I showed 100 % survivability in the challenge study. No gross and biochemical indication of acute or chronic toxicity were recorded. In conclusion, our results suggest that CAP-OMV nanoparticle can be a safe and efficient mucosal vaccine delivery system for RA, eliciting strong immune response in the host.

Dietary non-phytate phosphorus requirements for optimal productive and reproductive performance, and egg and tibial quality in egg-type duck breeders.

Optimal dietary non-phytate phosphorus (NPP) is essential in poultry to maximise productive and reproductive performance, along with indices of egg and bone quality. This study aimed to establish the NPP requirements of egg-type duck breeders aged from 54 to 80 weeks on the following traits: egg production, egg incubation, egg quality, tibial characteristics, reproductive organ, plasma indices, and the expression of genes related to phosphorus absorption. Longyan duck breeders aged 54 weeks (n = 300) were randomly allotted to five treatments, each containing six replicates of 10 individually caged birds. Birds were fed corn-soybean meal-based diets containing 0.18, 0.25, 0.32, 0.38, and 0.45% NPP/kg for 27 weeks. The tested dietary NPP levels did not affect egg production or egg quality indices. The hatchling weight of ducklings increased (quadratic, P < 0.01) as dietary NPP level increased, and the highest value occurred with 0.25% NPP. The number of large yellow follicles (LYF), and the relative weights of LYF and ovary showed linear and quadratic responses to dietary NPP levels; the lowest number and relative weight of LYF occurred with 0.38% NPP, and the lowest ovarian weight was obtained with 0.25% NPP. There were no differences in tibial length, breaking strength, and mineral density in response to dietary NPP levels. In contrast, tibial content of Ca increased (linear, P < 0.01) with dietary NPP levels increasing from 0.18 to 0.45%, and the tibial content of P increased at 0.32% NPP and the higher dietary NPP levels. Plasma concentration of P showed a quadratic (P < 0.05) response to the dietary NPP levels, where the highest value was seen at 0.38% NPP. In conclusion, dietary NPP levels from 0.18 to 0.45% had no effects on egg production, and egg and tibial quality of duck breeders. The duck breeders fed a diet with 0.25% NPP showed the highest hatchling weight of their offspring, while those fed 0.38% NPP had the lowest number and relative weight of LYF. These results indicated that the diet with 0.25% NPP can be used in egg-type duck breeders to improve the hatchling weight of their offspring, without adverse effects on their productivity. The regression model indicated that the maximal hatchling weight of ducklings was obtained from duck breeders fed the diet with 0.30% NPP.

The effect of epigallocatechin gallate on laying performance, egg quality, immune status, antioxidant capacity, and hepatic metabolome of laying ducks reared in high temperature condition.

Epigallocatechin gallate (EGCG) is a main component in green tea extract, which possesses multiple bioactivities. The present research studied the effects of EGCG on the laying performance, egg quality, immune status, antioxidant capacity, and hepatic metabolome of Linwu laying ducks reared under high temperature. A total of 180 42-w-old healthy Linwu laying ducks were allocated into control or EGCG-treated groups. Each treatment had 6 replicates with 15 ducks in each replicate. Diets for the two groups were basal diets supplemented with 0 or 300 mg/kg EGCG, respectively. All ducks were raised in the high temperature condition (35 ± 2 °C for 6 h from 10:00 to 16:00, and 28 ± 2 °C for the other 18 h from 16:00 to 10:00 the next day) for 21 days. Results showed that EGCG increased the egg production rate (p = 0.014) and enhanced the immunocompetence by improving serum levels of immunoglobulin A (p = 0.008) and immunoglobulin G (p = 0.006). EGCG also fortified the antioxidant capacity by activating superoxide dismutase (p = 0.012), catalase (p = 0.009), and glutathione peroxidase (p = 0.021), and increasing the level of heat-shock protein 70 (p = 0.003) in laying ducks' liver. At the same time, hepatic metabolomics result suggested that EGCG increased the concentration of several key metabolites, such as spermidine (p = 0.031), tetramethylenediamine (p = 0.009), hyoscyamine (p = 0.026), ß-nicotinamide adenine dinucleotide phosphate (p = 0.038), and pantothenic acid (p = 0.010), which were involved in the metabolic pathways of glutathione metabolism, arginine and proline metabolism, ß-alanine metabolism, and tropane, piperidine, and pyridine alkaloid biosynthesis. In conclusion, 300 mg/kg dietary EGCG showed protection effects on the laying ducks reared in high temperature by improving the immune and antioxidant capacities, which contributed to the increase of laying performance of ducks. The potential mechanism could be that EGCG modulate the synthesis of key metabolites and associated metabolic pathways.

Research Note: Transcriptome analysis reveals differentially expressed genes regulated muscle development in Pekin ducks during dietary threonine deficiency.

To investigate the underlying molecular mechanism of threonine (Thr) regulation on the development of breast muscle in Pekin ducks, 240 male Pekin ducks at 1 d of age were fed a Thr deficiency diet (Thr-D), Thr sufficiency diet (Thr-S), or Thr excess diet (Thr-E) for 21 d. The results showed that Thr-D reduced body weight (BW), average weight gain (ADG), and average feed intake (ADFI), and increased the feed/gain (F/G) in Pekin ducks (P < 0.05), and Thr-E did not affect BW, ADG, ADFI, or F/G (P > 0.05), compared with Thr-S. The diameter and cross-sectional area of the breast muscle fibers in the Thr-S group were larger than those in the Thr-D group (P < 0.05). RNA sequencing revealed 1,300 differential expressed genes (DEGs) between the Thr-D and Thr-S groups, of which 625 were upregulated and 675 were downregulated by Thr-D. KEGG analysis showed that the upregulated genes were enriched in mTOR, FoxO, Wnt, fat digestion and absorption, and other signaling pathways. The downregulated genes were enriched in the MAPK signaling, glycolysis/gluconeogenesis, adipocytokine signaling, and biosynthesis of unsaturated fatty acids signaling pathways. The genes of Wnt family member 3a (Wnt3a), myogenin, myozenin 2, and insulin like growth factor 2 mRNA binding protein were upregulated, and platelet derived growth factor subunit B, PDGF receptor beta and Wnt4 were downregulated by Thr deficiency, which involving in muscle development. Our findings indicated that Thr increased breast fiber size, perhaps because Thr affected the proliferation and differentiation of satellite cells in breast muscle of ducks after hatch. Our results provide novel insights into new understanding of the molecular mechanisms underlying breast muscle development in ducks subjected to dietary Thr.

Effects of lysophospholipids and multi-enzymes on growth performance, antioxidant capacity, intestinal health, and cecal microflora of male cherry valley ducks.

Improvement of nutrient utilization to promote growth performance is always pursued in poultry. In this study, a total of 360 1-d-old male ducklings was randomly assigned to 3 treatments in terms of diet treatment groups. Three treatments were as follows: basal diet (Con group) or basal diet supplemented with 300 mg/kg multi-enzymes (ENZ group) or 500 mg/kg lysophospholipids (LPL group). On day 42, ducks were slaughtered for samplings. The results revealed that supplementary LPL improved the body weight (BW) at day 14 and average daily gain (ADG) during days 1 to 14 and improved the feed conversion rate (FCR) for the overall period (P < 0.05) by improving nutrient utilization of dry matter and ether extract (P < 0.05) compared with the Con group. Dietary ENZ improved the FCR from days 15-42 and 1-42, and nitrogen utilization (P < 0.05) compared with the Con group. Jejunal villus height and villus height/crypt depth ratio were higher (P < 0.05) in the LPL group and tended to be higher (P < 0.1) in the ENZ group compared to the Con group. Supplementation with either LPL or ENZ reduced interleukin-1ß concentration in jejunal mucus (P < 0.05). Both LPL and ENZ enhanced serum total superoxide dismutase activity (P < 0.05), whereas only supplementation with LPL elevated total antioxidant capacity (P < 0.05). In terms of cecal microbiota, microbial richness tended to be reduced by LPL, with low observed-OTUs and Chao1 (0.05 < P < 0.1). Supplementation with ENZ led to higher abundances of cellulolytic bacteria such as Fibrobacterota, [Eubacterium]_xylanophilum_group, and Bifidobacterium. Overall, both LPL and ENZ improved FCR, which may be relevant to ameliorative intestinal health, overall antioxidant ability, and cecal microbiome.

Well known in the industry, enhancing nutrient utilization in meat ducks is a vital sustainability tactic to manage production costs. This is especially relevant because meat ducks require more feed, and grain prices are on the rise. Lysophospholipids (LPL) have been confirmed to effectively emulsify fat, which boosts fat utilization. Additionally, multi-exogenous enzymes (ENZ) play a significant role in nutrient breakdown. Our feeding experiment on Cherry Vallery male ducks demonstrated that a dietary supplement of LPL at 500 mg/kg improves the body weight, average daily gain, and feed conversion rate during the starter period. It also elevates the feed conversion rate over the entire period, enhances ether extract utilization, and positively impacts jejunal morphology development in the finishing phase. However, LPL negatively affects the α-diversity of cecal flora. On the other hand, supplementing with 300 mg/kg ENZ improves the feed conversion rate throughout the period, increases nitrogen utilization in the finisher phase, diminishes interleukin-1ß levels in the jejunum, elevates superoxide dismutase in the serum, and promotes the prevalence of cellulolytic bacteria. In summary, feed supplemented with 500 mg/kg LPL and 300 mg/kg ENZ aids in reducing the FCR of meat ducks.

Improvement of diluted semen from Muscovy (Cairina moschata) drakes by the addition of water-soluble antioxidants.

The aim of this study was to evaluate the effect of antioxidant supplementation in diluted semen from Muscovy drakes after the induction of oxidative stress (OS) on the sperm motility, kinematic parameters and biochemical markers - lipid peroxidation (LPO) levels and total glutathione (tGSH) concentration. The pooled semen was distributed equally into three parts, diluted (1:3 v/v) with IMV Canadyl, HIA-1 or AU, and stored at 4°C for 6 h. Later, the semen was equilibrated at 20-25°C for 15 min, and divided in Eppendorf tubes. The sperm samples (final concentration of 50 × 106 sperm cells/mL per sample) were incubated at 37°C for 30 min in the absence (-) or presence (+) of 0.1 mM FeSO4 + 0.5 mM H2 O2 (Fenton system) and the following combinations of antioxidants: ascorbic acid + Trolox (A + T); ascorbic acid + Desferal (A + D); Trolox + Desferal (T + D) and ascorbic acid + Trolox + Desferal (A + T + D), all of them in a final concentration of 0.1 mM. Thus, the total number of samples was 30 and in each one, the sperm motility, velocity parameters, LPO and tGSH were determined. The motility and kinematic parameters of the diluted semen with added antioxidants were restored by up to 20% after inducing OS via the Fenton reaction. Dual combinations of antioxidants (A + T, A + D, and T + D) lowered LPO levels, but not equally across different extenders. After the induction of OS, the tGSH levels in diluted semen with IMV-Canadyl were not affected by the added antioxidants. Whereas antioxidant combinations in diluted semen with HIA-1 or AU had a beneficial effect and partially restored tGSH levels. In conclusion, the results showed that the extender IMV-Canadyl is well balanced and protected the Muscovy semen under OS conditions, while the other two extenders HIA-1 and AU can be improved by adding antioxidants.

Effect of Bacillus toyonensis BCT-7112T supplementation on growth performance, intestinal morphology, immune-related gene expression, and gut microbiome in Barbary ducks.

This study aimed to investigate the effect of Bacillus toyonensis BCT-7112T supplementation on growth performance, intestinal morphology, immune-related gene expression, and the cecal microbiota of meat ducks. A total of 150 one-day-old male Barbary ducks were divided into 3 groups with 5 replicates (n = 10 ducks per replicate) by completely randomized design and offered diets supplemented with the commercial product Toyocerin (containing 1 × 109B. toyonensis BCT-7112T viable spores/g product) at the levels of 0, 500, or 1,000 mg/kg (0, 500, or 1,000 ppm), respectively, for 8 wk. The results showed that although ducks in the 500 ppm B. toyonensis BCT-7112T group displayed numerically better values (e.g., weight gain and feed conversion ratio) than those in the control group, the growth performance of ducks fed diets supplemented with B. toyonensis BCT-7112T did not differ significantly from that of the control group (P > 0.05). There were no significant differences in the intestinal mucosal morphology of ducks across the experimental groups (P > 0.05). However, ducks in the 500 ppm B. toyonensis BCT-7112T group showed a trend of greater values, for example, villus height per crypt depth of duodenum (P = 0.16) and ileum (P = 0.12) compared with those in the control group. The relative expression of immune-related genes, for example, interferon (IFN) and interleukin-6 (IL-6) in the meat duck spleen was significantly lower in both B. toyonensis BCT-7112T groups at 14 d and 35 d than in the control group (P < 0.05). Beta diversity analysis of the cecal microbiota of ducks in either the 500 ppm or the 1,000 ppm B. toyonensis BCT-7112T group showed to have higher diversity than that in the control group, where at the phylum level, Bacteroidetes was the most abundant, followed by Firmicutes, and at the genus level, Bacteroides, Fusobacterium, and Ruminococcaceae were the top 3 most abundant genera. In conclusion, our study demonstrates that 500 ppm supplementation with B. toyonensis BCT-7112T in duck diets can reduce proinflammatory cytokine gene expression, improve immunological function, and increase the variety of microbial communities in the ceca of meat-type ducks.

Organic zinc glycine chelate is better than inorganic zinc in improving growth performance of cherry valley ducks by regulating intestinal morphology, barrier function, and the gut microbiome.

Zinc (Zn) is an essential trace element that has physiological and nutritional functions. However, excessive use of Zn can lead to waste of resources. In this study, we compared the effects of inorganic (ZnSO4) and organic Zn glycine chelate (Zn-Gly) on the growth performance, intestinal morphology, immune function, barrier integrity, and gut microbiome of Cherry Valley ducks. We randomly divided 180 one-day-old male meat ducks into three groups, each with six replicates of 10 birds: basal diet group (CON), basal diet with 70 mg Zn/kg from ZnSO4 (ZnSO4 group), and basal diet with 70 mg Zn/kg from Zn-Gly (Zn-Gly group). After 14 and 35 d of feeding, birds in the Zn groups had significantly increased body weight and average daily gain (ADG), decreased intestinal permeability indicator d-lactate, improved intestinal morphology and barrier function-related tight junction protein levels, and upregulated mucin 2 and secretory immunoglobulin A levels compared to the control (P < 0.05). Additionally, compared to the ZnSO4 group, we found that supplementation with Zn-Gly at 70 mg/kg Zn resulted in the significant increase of body weight at 35 d, 1 to 35 d ADG and average daily feed intake, villus height at 14 and 35 d, secretory immunoglobulin A and immunoglobulin G at 14 d, and mucin 2 mRNA level at 14 d (P < 0.05). Compared with the control group, dietary Zn had a significant effect on the gene expression of metallothionein at 14 and 35 d (P < 0.05). 16S rRNA sequencing showed that Zn significantly increased alpha diversity (P < 0.05), whereas no differences in beta diversity were observed among groups (P > 0.05). Dietary Zn significantly altered the cecal microbiota composition by increasing the abundances of Firmicutes, Blautia, Lactobacillus, Prevotellaceae NK3B31, and [Ruminococcus] torques group and reducing that of Bacteroides (P < 0.05). Spearman correlation analysis revealed that the changes in microbiota were highly correlated (P < 0.05) with growth performance, intestinal morphology, and immune function-related parameters. Taken together, our data show that, under the condition of adding 70 mg/kg Zn, supplementation with Zn-Gly promoted growth performance by regulating intestinal morphology, immune function, barrier integrity, and gut microbiota of Cherry Valley ducks compared with the use of ZnSO4 in feed.

Zinc (Zn) is an essential trace element that is required for physiological and nutritional functions, but excessive use of Zn can lead to environmental pollution. Few studies have directly compared the impact of different Zn sources on growth performance and intestinal barrier function in Cherry Valley ducks. This study was conducted to investigate the effects of two sources of Zn (inorganic ZnSO4 or organic Zn glycine chelate, Zn-Gly) on growth performance, intestinal morphology, barrier function, and gut microbiome of ducks. Compared to the ZnSO4 group, we found that supplementation with Zn-Gly resulted in the significant increase of body weight at 35 d, 1 to 35 d average daily gain and average daily feed intake, villus height at 14 and 35 d, secretory immunoglobulin A and immunoglobulin G at 14 d, and mucin 2 mRNA level at 14 d. At the genus level, the relative abundance of Blautia was higher in the Zn-Gly group than that in the control and ZnSO4 group. Therefore, Zn-Gly supplementation at 70 mg/kg Zn had positive effects in promoting growth performance by regulating intestinal morphology, barrier function, and gut microbiota of ducks when compared with the same dosage use of ZnSO4 in feed.

Effects of linseed oil supplementation duration on fatty acid profile and fatty acid metabolism-related genes in the muscles of Chinese crested white ducks.

Meat rich in polyunsaturated fatty acids is considered beneficial to health. Supplementing the diet with linseed oil promotes the deposition of polyunsaturated fatty acids (PUFAs) in poultry, a conclusion that has been confirmed multiple times in chicken meat. However, fewer studies have focused on the effects of dietary fatty acids on duck meat. Therefore, this study aims to evaluate the effects of the feeding time of a linseed oil diet on duck meat performance and gene expression, including meat quality performance, plasma biochemical indicators, fatty acid profile, and gene expression. For this study, we selected 168 Chinese crested ducks at 28 days old and divided them into three groups, with 56 birds in each group. The linseed oil content in the different treatment groups was as follows: the control group (0% flaxseed oil), the 14d group (2% linseed oil), and the 28d group (2% linseed oil). Ducks in the two experimental groups were fed a linseed oil diet for 28 and 14 days at 28 and 42 days of age, respectively. The results showed that linseed oil had no negative effect on duck performance (slaughter rate, breast muscle weight, and leg muscle weight) or meat quality performance (pH, meat color, drip loss, and shear force) (P > 0.05). The addition of linseed oil in the diet increased plasma total cholesterol and high-density lipoprotein cholesterol levels (P < 0.05), while decreasing triglyceride content (P < 0.05). Furthermore, the supplementation of linseed oil for four weeks affected the composition of muscle fatty acids. Specifically, levels of α-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid were increased (P < 0.05), while eicosatetraenoic acid content was negatively correlated with flaxseed oil intake (P < 0.05). qRT-PCR analysis further revealed that the expression of FATP1, FABP5, and ELOVL5 genes in the breast muscle, as well as FABP3 and FADS2 genes in the thigh muscle, increased after four weeks of linseed oil supplementation (P < 0.05). However, after two weeks of feeding, CPT1A gene expression inhibited fatty acid deposition, suggesting an increase in fatty acid oxidation (P < 0.05). Overall, the four-week feeding time may be a key factor in promoting the deposition of n-3 PUFAs in duck meat. However, the limitation of this study is that it remains unknown whether longer supplementation time will continue to affect the deposition of n-3 PUFAs. Further experiments are needed to explain how prolonged feeding of linseed oil will affect the meat quality traits and fatty acid profile of duck meat.

Plant essential oils improve growth performance by increasing antioxidative capacity, enhancing intestinal barrier function, and modulating gut microbiota in Muscovy ducks.

Essential oils (EO) are known for their antioxidant, anti-inflammatory, antimicrobial, and growth-promoting properties. However, data rgarding their impact on the intestinal health and gut microbiota of ducks remain limited. Thus, this study aimed to investigate the effects of plant EO on the growth performance, intestinal health, and gut microbiota of Muscovy ducks. A total of 360 healthy male Muscovy ducks aged 1 d were randomly divided into 4 groups with 6 replicates and 15 ducks per replicate. Ducks were fed basal diets supplemented with 0, 100, 200, or 300 mg/kg EO. The results showed that 200 mg/kg EO supplementation significantly (P < 0.05) increased the final body weight and average daily gain, while significantly (P < 0.05) decreased the feed conversion ratio during the 56-d experimental period. Furthermore, dietary 200 mg/kg EO significantly (P < 0.05) enhanced antioxidant capacity and immune function and improved the barrier function of the intestine. Additionally, 16S rDNA sequencing analysis results showed that 200 mg/kg EO favorably modulated the cecal microbial diversities and composition evidenced by the increased (P < 0.05) the abundances of short-chain fatty acid-producing bacteria (e.g., Subdoligranulum and Shuttleworthia) and decreased (P < 0.05) abundances of potential enteric pathogenic bacteria (e.g., Alistipes, Eisenbergiella, and Olsenella). The relative abundance of beneficial bacteria was positively correlated with antioxidant, immune, and barrier function biomarkers. Overall, these findings revealed that dietary supplementation with 200 mg/kg EO had several potentially beneficial effects on the growth performance of Muscovy ducks by improving antioxidant capacity, enhancing the intestinal barrier function and favorably modulating gut microbiota.

Effects of dietary nano-selenium supplementation on Riemerella anatipestifer vaccinated and challenged Pekin ducklings (Anas platyrhynchos).

Riemerella anatipestifer (RA) is a common disease causing economic losses to duck farms worldwide. Novel supplements are crucially needed to control this bacterium, enhance poultry performance, and produce synergistic effects with vaccines in stimulating the immune system. This study investigated the effect of nano-selenium (Nano-Se) on the vaccinated (VAC) and challenged (Ch) Pekin ducklings (Anas platyrhynchos) with RA. Five experimental groups (G1-G5) were included in this study: G1 was the control group, G2 was the RA-challenged group, G3 was the Nano-Se+Ch group, G4 was the VAC+Ch group, and G5 was the Nano-Se+VAC+Ch group. The Nano-Se (0.3 mg/kg diet) was supplemented for 5 weeks post-vaccination (PV). The ducklings were vaccinated subcutaneously with the RA vaccine at 7 days of age and challenged with RA at the 3rd week PV. Blood, pharyngeal swabs and tissue samples were collected at the 3rd week PV and at different times post-challenge (PC). The growth performance (weight gain and feed conversion ratio), clinical signs, gross lesions, mortality, bacterial shedding, haematological, immunological, and biochemical parameters, cytokines production, and histopathological lesion scores showed significant differences (P < 0.05) between the challenged (G2) group and the supplemented (G3 & G5) groups. G5 showed the highest (P < 0.05) growth performance, phagocytic activity, IgM and IgG, splenic interleukin-2 (IL-2), IL-10, and interferon-gamma (IFN-γ) gene expressions, and the lowest mortality, bacterial shedding, hepatic and renal damage, heterophil/lymphocyte ratio and lesion scores compared to the other groups. In conclusion, the supplementation of nano-selenium for five weeks in the diet can improve the growth performance, immune status, and cytokines production in ducklings vaccinated and challenged with RA.

Effects of coated sodium butyrate on growth performance, intestinal morphology, and caecal short-chain fatty acids of growing Pekin ducks.

1. A dose‒response experiment with six supplemental levels of coated sodium butyrate (CSB) (0, 250, 500, 750, 1,000, and 1,250 mg/kg) was conducted to investigate its effects on growth performance, intestinal morphology, and caecal short-chain fatty acids of growing Pekin ducks aged 14 to 35 d. A total of 288 male 14-d-old Pekin ducks were randomly allocated to six dietary treatments. Each treatment had eight replicate pens of six ducks per pen.2. The daily weight gain, daily feed intake, and feed/gain of ducks from 14 to 35 d of age were not influenced by increasing CSB levels. The relative weight and length of the duodenum, jejunum, and caecum increased linearly or quadratically as supplemental CSB increased (P < 0.05).3. For the ileum and caecum, the villus height and height/crypt depth increased linearly or quadratically, and the villus crypt depth decreased linearly as the supplemental CSB increased (P < 0.05). As supplemental CSB increased, the goblet cell numbers of the ileum increased and decreased and changed quadratically (P < 0.05), but caecal goblet cell number increased quadratically (P < 0.05). Increasing the CSB level linearly or quadratically elevated the concentrations of propionic acid and butyric acid in the caecum (P < 0.05).4. It was concluded that CSB can be used as a safe and effective feed additive to promote the intestinal integrity of growing ducks by improving intestinal morphology and increasing the concentration of caecal short-chain fatty acids.

Dietary supplementation of coated sodium butyrate improves growth performance of laying ducks by regulating intestinal health and immunological performance.

Introduction: This study was conducted to assess the effects of dietary supplementation of coated sodium butyrate (CSB) on the growth performance, serum antioxidant, immune performance, and intestinal microbiota of laying ducks. Methods: A total of 120 48-week-old laying ducks were randomly divided into 2 treatment groups: the control group (group C fed a basal diet) and the CSB-treated group (group CSB fed the basal diet + 250 g/t of CSB). Each treatment consisted of 6 replicates, with 10 ducks per replicate, and the trial was conducted for 60 days. Results: Compared with the group C, the group CSB showed a significant increase in the laying rate (p<0.05) of the 53-56 week-old ducks. Additionally, the serum total antioxidant capacity, superoxide dismutase activity and immunoglobulin G level were significantly higher (p<0.05), while the serum malondialdehyde content and tumor necrosis factor (TNF)-a level were significantly lower (p<0.05) in the serum of the group CSB compared to the group C. Moreover, the expression of IL-1b and TNF-a in the spleen of the group CSB was significantly lower (p<0.05) compared to that of the group C. In addition, compared with the group C, the expression of Occludin in the ileum and the villus height in the jejunum were significantly higher in the group CSB (p<0.05). Furthermore, Chao1, Shannon, and Pielou-e indices were higher in the group CSB compared to the group C (p<0.05). The abundance of Bacteroidetes in the group CSB was lower than that in the group C (p<0.05), while the abundances of Firmicutes and Actinobacteria were higher in the group CSB compared to the group C (p<0.05). Conclusions: Our results suggest that the dietary supplementation of CSB can alleviate egg-laying stress in laying ducks by enhancing immunity and maintaining the intestinal health of the ducks.