Search Results (53)

The objective of this study was to investigate alterations in nutrient utilization, standardized ileal digestibility of amino acids (SIDAA), and intestinal health in response to heat stress (HS) in Pekin ducks. A total of 240 healthy 28-day-old male Pekin ducks were randomly allocated to three groups: a normal control (NC) group, an HS group, and a pair-fed (PF; provided an amount of feed equal to that consumed by the HS group to eliminate the effects of feed intake) group, each with eight replicate cages of ten birds. The results showed that HS significantly reduced the apparent utilization of dietary energy, ether extract, and crude protein compared to both the NC and PF groups (p < 0.05), but yielded comparable SIDAA to the PF group. The HS group exhibited reduced mRNA levels of EAAT3 and PepT1, along with elevated mRNA levels of CAT1, GLUT5, and FATP6 in the jejunum compared to the NC or PF groups, respectively (p < 0.05). Furthermore, HS resulted in a significant deterioration of jejunal morphology and goblet cell count compared to the NC and PF groups (p < 0.05). Serum fluorescein isothiocyanate-dextran levels were significantly higher in HS ducks than in NC ducks (p < 0.05), but did not differ from PF ducks. At order-level classification of ileal mucosal microbiota, HS markedly increased the relative abundance of Bacillales, Deferribacterales, and Actinomycetales versus NC (p < 0.05), while significantly decreasing Bifidobacteriales abundance relative to PF (p < 0.05). Collectively, HS induces a leaky gut and microbiota dysbiosis that compromises gut health, thereby reducing dietary nutrient utilization in Pekin ducks. The observed reduction in feed intake constitutes a primary driver of intestinal health deterioration in heat-stressed Pekin ducks. Full article

The aim of this study was to evaluate selected reproductive traits and estimate selected meat traits of male and female ducks of strains P-11 and P-22 during the rearing period, in order to analyse the differences between the two duck populations in terms of these traits in three consecutive generations, i.e., in the years 2020–2022. The birds were kept at the Duck Breeding Centre in Lińsk, Kuyavian-Pomeranian Voivodeship. This study was conducted using all individually tagged individuals of both sexes of known origin and lineage. The birds were kept under standard conditions, and incubation and hatching were carried out in accordance with applicable technology. Reproductive traits were evaluated in three generations of ducks, and meat traits were evaluated during rearing. Ducks of strain P-11 were shown to have a higher laying rate than P-22 ducks, a higher egg fertilization rate, and higher hatching rates of healthy ducklings from set eggs and fertilized eggs, which confirms the differences between the two populations. Average egg fertilization rates during the three-year study period ranged from 92.38% to 94.71% in strain P-11 and from 91.37% to 92.80% in strain P-22. The rates of healthy ducklings hatched from set eggs ranged from 72.24% to 78.15% in strain P-11 and were 2.89% to 4.73% higher than for strain P-22. Egg weight at peak laying (above 80%) ranged from 91.9 to 92.3 g in strain P-22 and from 89.2 to 89 g in strain P-11, and the heritability coefficients for both strains were within the range for moderately heritable traits. Statistically significant differences were shown between the two populations for all meat traits evaluated during the rearing period, i.e., body weight at 3 and 7 weeks of age, keel length, and breast muscle thickness, in each of the three years of this study (three successive generations of birds). Male ducks had higher body weight, better musculature, and higher fat content than females. In addition, the males and females of strain P-22 had higher values for these traits than the birds of strain P-11. Minor changes were observed in successive generations in the values for these traits, as well as in the heritability coefficients estimated from variance for fathers (h²_S), mothers (h²_D), and fathers and mothers (h²_SD). For most meat traits, the heritability coefficients estimated from the variance for fathers (h²_S), mothers (h²_D), and fathers and mothers (h²_SD) took on values from low to high in both strains. Full article

Background: Pekin ducks are well-known meat-type ducks, whereas Shaoxing ducks are bred for their egg-laying abilities. Growth and development of poultry species is well studied; however, very little is known regarding differences in intestinal gene expression between Pekin and Shaoxing ducks. Methods: To investigate intestinal differences between Pekin and Shaoxing ducks, we conducted transcriptome analysis on ileal and cecal tissues from five 42-day-old ducks per breed, raised under identical housing and feeding conditions to minimize environmental influences. Results: The results showed that a total of 379 differentially expressed genes (DEGs) with p < 0.05 and |log₂FoldChange| > 1 were identified in the ileum when Pekin ducks were compared to Shaoxing ducks, among which 158 were upregulated and 221 were downregulated. Compared to Shaoxing ducks, a total of 367 DEGs with p < 0.05 and |log₂FoldChange| > 1 were identified in the ceca of Pekin ducks, among which 204 were upregulated and 163 were downregulated. Among these DEGs, nine genes were reported to be associated with growth and metabolism, namely, P2RX6, KCNJ6, CASQ2, EHHADH, ACSBG1, ELOVL4, AIF1L, VILL, and FABP1. Functional enrichment analyses using the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases indicated that the DEGs were significantly involved in pathways such as calcium signaling, unsaturated fatty acid biosynthesis, fatty acid degradation, and tryptophan metabolism. Conclusions: In conclusion, our study identified transcriptome differences in the intestines of meat-type and laying-type ducks, offering insights into the genetic basis of their growth and metabolic differences. Future studies should validate key genes and explore environmental influences on gene expression. Full article

The aim of this study was to identify the feather section, among the whole feather, rachis, and vane, with the highest reliability for corticosterone measurement in 10 Pekin ducks aged 42 days. In total, 60 samples (i.e., 20 per section) were collected and each section was analyzed in duplicate. Corticosterone levels were measured using ELISA and statistical analyses were performed using ANOVA in SAS 9.2, and the intra-class correlation coefficient (ICC) was tested using IBM SPSS. The level in the whole feather (12.55 ± 4.41 pg/mg) was significantly lower (p < 0.001) than that in the rachis (18.12 ± 5.70 pg/mg). No significant differences were observed between the rachis and the vane (20.40 ± 3.04 pg/mg). ANOVA results confirmed substantial hormonal variability depending on the feather part analyzed. The ICCs for the whole feather, rachis, and vane were 0.923, 0.876, and 0.004, respectively. The vane section exhibited the highest concentration and lowest variance, whereas the whole feather exhibited the highest ICC. Although the whole feather had the lowest concentration, it exhibited greater consistency. Further research is necessary to improve the feather corticosterone analysis method for more accurate analysis. In conclusion, the whole feather provides the most reliable measure of corticosterone concentration among the three parts. Full article

Reproductive performance is an important trait in poultry production. Traditional methods of improving reproductive traits can only use recorded information from females, making it difficult to effectively assess the reproductive potential of males. Although genomic selection is thought to remedy this shortcoming, most studies now use simulated data or one or two generations of data to assess its effects. Also, the effectiveness of genomic selection for use in the improvement of reproductive traits in ducks has hardly been reported. In this study, data from four consecutive generations of Pekin duck populations were used to assess the effect of genomic selection on reproductive trait improvement. Whole-genome resequencing was performed for genotyping, and pedigree and SNP genetic parameters were evaluated. Using the BLUP (Best Linear Unbiased Prediction), GBLUP (Genomic Best Linear Unbiased Prediction), and ssGBLUP (Single-step Genomic Best Linear Unbiased Prediction) models, we assessed selection progress for body weight at 6 weeks, age at first egg, and egg number from 25 to 44 weeks over multiple generations. Ten-fold cross-validation was used to evaluate the genomic prediction performance. The results indicated that the heritability of growth traits decreased after routine selection, while reproductive and egg quality traits maintained moderate heritability (0.2–0.4). Selection progress showed a one-day advancement in age at first egg and an increase of one egg per generation from the 13th to 15th generations. The GBLUP model performance significantly outperformed BLUP, but ssGBLUP showed minimal improvement due to comprehensive genotyping. In conclusion, this study provides crucial insights for optimizing breeding strategies and improving economic efficiency in Pekin duck breeding. Full article

Background: Sebum deposition is a vital trait influencing meat quality and production efficiency in Pekin ducks. Providing insights into the genetic basis of fat deposition could help improve breeding strategies aimed at producing high-quality meat ducks. This study aimed to identify the genetic mechanisms and lipid metabolism pathways regulating subcutaneous and intramuscular fat deposition in two Pekin duck strains: Nankou No. 1 and Jingdian. Methods: A total of 72 male ducks, Nankou No. 1 (n = 36) and Jingdian (n = 36), were raised under controlled conditions for 42 days. On days 28, 35, and 42, ducks from each group were selected and slaughtered, and their subcutaneous and liver tissues were collected to analyze lipid enzyme activities. On day 42, additional ducks from each strain were slaughtered and evaluated for carcass performance, as well as intramuscular and sebum yield. Genome-wide association analysis (GWAS) was conducted in the Nankou No. 1 strain. Conclusion: Our results showed statistically significant differences in intramuscular and subcutaneous fat yield between the two strains, with Nankou No. 1 exhibiting a higher yield than Jingdian (p < 0.05). The GWAS results identified 96 significant single nucleotide polymorphisms (SNPs), associated with sebum deposition. Functional annotation identified ALDH7A1 as a key candidate gene involved in lipid metabolism and fat storage regulation in Pekin ducks, Nankou No. 1 strain. Enzyme activity assays in liver and subcutaneous tissues revealed breed-specific differences in lipid metabolism, aligning with genetic findings. The activities of the lipid enzymes changed over time, suggesting changes in the developmental stages. The results on fat yield and enzymatic activities further align with molecular findings from the GWAS, which identified variations in lipid metabolism pathways. These results highlight genetic markers and biochemical pathways related to fat deposition in Pekin ducks, offering new insights for selective breeding programs aimed at optimizing fat content in meat production. Further research is needed to clarify the specific role of ALDH7A1 in lipid metabolism and its potential to enhance fat deposition traits in poultry. Full article

RNA editing is increasingly recognized as a post-transcriptional modification that directly affects viral infection by regulating RNA stability and recoding proteins. the duck hepatitis A virus genotype 3 (DHAV-3) infection is seriously detrimental to the Asian duck industry. However, the landscape and roles of RNA editing in the susceptibility and resistance of Pekin ducks to DHAV-3 remain unclear. Here, we profiled dynamic RNA editing events in liver tissue and investigated their potential functions during DHAV-3 infection in Pekin ducks. We identified 11,067 informative RNA editing sites in liver tissue from DHAV-3-susceptible and -resistant ducklings at three time points during virus infection. Differential RNA editing sites (DRESs) between S and R ducks were dynamically changed during infection, which were enriched in genes associated with vesicle-mediated transport and immune-related pathways. Moreover, we predicted and experimentally verified that RNA editing events in 3′-UTR could result in loss or gain of miRNA–mRNA interactions, thereby changing the expression of target genes. We also found a few DRESs in coding sequences (CDSs) that altered the amino acid sequences of several proteins that were vital for viral infection. Taken together, these data suggest that dynamic RNA editing has significant potential to tune physiological processes in response to virus infection in Pekin ducks, thus contributing to host differential susceptibility to DHAV-3. Full article

Short beak and dwarfism syndrome (SBDS), characterised by growth retardation and short beak, is a contagious disease of ducks, caused by goose parvovirus (GPV). This study aimed to compare morphology and biochemistry data obtained from 4-week-old Pekin ducks naturally infected with parvovirus causing SBDS in healthy Pekin ducks of the same age. Materials and Methods: Forty Pekin ducks (twenty infected GPV and twenty clinically healthy controls) were examined. Measurement of the beak and metatarsus and histopathological examination were conducted, and blood morphological and biochemical analyses were performed for each individual. Results: Statistically significant increases in the SBDS group were observed in white blood cells (WBCs), alkaline phosphatase (ALP), and albumin levels, while decreases were noted in non-organic phosphorus, potassium, and amylase levels. ALP in the control group was 465.70 ± 161.49, while in the SBDS group it was 353.68 ± 79.97 (p ˂ 0.006). 1,2-o-dilauryl-rac-glycero-3-glutaric acid-(6′-methylresorufin) ester (DGGR) lipase marker offered a refined gauge for pancreatic function, with established reference values for the healthy control group set at 14.95 ± 4.27 U/L. Conclusions: This study sheds light on the unique impact of GPV on the skeletal system of Pekin ducks, revealing significant insights into the mechanisms of SBDS without osteitis. Additionally, this work offers groundbreaking insights into the morphological and biochemical alterations in the blood during SBDS, establishing normative haematological and biochemical indices for Pekin ducks. It also introduces the DGGR lipase marker as a refined marker for pancreatic function for the healthy control group set at 14.95 ± 4.27 U/L. It highlights the role of ALP in ensuring proper bone growth and the need for ongoing research on its activity in the context of viral infections. Full article

The present study investigated the effect of supplementing a multi-carbohydrase enzyme complex (MCE) in corn–soy-based diets of Pekin ducks. The treatments were as follows: positive control (PC, 2980 and 3120 kcal/kg for starter and grower, respectively); negative control (NC, −132 kcal/kg energy reduction to PC achieved by reduction of fat and wheat middlings as filler); NC + MCE at 75 ppm (E75); 100 ppm (E100); and 125 ppm (E125) randomly distributed in 10 replicate pens with 25 birds each. Performance was evaluated after 14 and 35 d. On day 36 of the trial, five ducks/pen were processed to evaluate carcass traits. During days 1–14, the PC had a lower (p < 0.01) feed intake compared to all other treatments. At 14 and 35 d of age the NC decreased (p < 0.001) the body weight (BW) of the ducks compared to the PC by −8.3% and −5.3%, respectively. The NC BW was lower (p < 0.001) compared to all MCE-supplemented treatments at 14 and 35 d. The BW of E75, E100, and E125 treatments was not different (p > 0.05) from the PC at both evaluation periods. Cumulatively (1–35 d), the NC resulted in a weight-adjusted FCR increase (p = 0.001) of 9.9% compared to the PC, and the FCR of E75, E100, and E125 were able to recover 72.3%, 66.4%, and 63.5%, respectively, compared to the PC. The carcass and breast weights were lower (p < 0.001) in the NC compared to all other treatments, and no differences (p > 0.05) were observed between the MCE-supplemented treatments and the PC. In conclusion, these results suggest that the MCE supplementation can maintain duck growth performance with no negative effects on carcass traits in energy-reduced corn–soybean meal-based diets. From the results of the trial, 75 ppm MCE delivered the best performance recovery and 125 ppm MCE supplementation had the best % breast yield. Full article

Body size is an important growth indicator in ducks and is a primary selection criterion for physical improvement. An excessively rapid growth rate in meat ducks can result in excessive body size, which may hinder subsequent processing and slaughter operations. However, only a few molecular markers related to body size have been studied in meat ducks. In this study, we performed a genome-wide association study (GWAS) to identify candidate genes and QTLs affecting body length (BL), keel bone length (KBL), neck length (NL), and breast width (BrW) in Pekin ducks (Anas platyrhynchos domestica). Our results indicate the significant SNP for NL is located within a pseudogene, whereas the significant SNP for BrW is located in an intergenic region. More importantly, our analysis identified a haplotype that was significantly associated with both BL and KBL. This haplotype, containing 48 single-nucleotide polymorphisms (SNPs), is localized within the XKR4 gene. The identification of this haplotype suggests that XKR4 may be a key candidate gene influencing BL and KBL in Pekin ducks. These findings have important implications for the breeding and genetic improvement of Pekin ducks, and provide valuable insights into the genetic architecture of body size traits in this species. Full article

The intensive raising model for meat duck production has widely adopted cascading cages. However, investigations on low-protein diets for Pekin ducks under this model are scarce. Thus, a 3 × 6 factorial experiment was conducted using six dietary crude protein (CP) levels (17.61%, 16.25%, 15.34%, 14.55%, 13.38%, and 12.64%, analyzed) and three cage layers (lower, middle, and upper). The study aimed to examine the effects of dietary CP reduction with crystalline amino acid supplementation on growth performance, carcass traits, and apparent nutrient digestibility in growing Pekin ducks from 21 to 42 days of age housed at different cage layers. A total of 1620 21-day-old Pekin ducks were randomly divided into 18 groups, each with six replicates of 15 ducks per replicate. Ducks were distributed across different cage layers and were fed one of six experimental diets, respectively, each varying in dietary CP levels but maintaining similar dietary energy and amino acid profiles. The results showed that the reduction in dietary CP levels affected growth performance (p < 0.05), while weight gain, feed intake, and feed/gain of Pekin ducks had no difference among 17.61%, 16.25%, and 15.34% CP groups (p > 0.05). As dietary CP decreased, abdominal fat yield increased (p < 0.05), but breast and leg meat yields were unaffected (p > 0.05). CP intake, nitrogen intake, and nitrogen excretion decreased linearly (p < 0.05) with decreasing dietary CP levels, while apparent nutrient digestibility in Pekin ducks increased proportionally (p < 0.05). Additionally, body weight, weight gain, feed intake, CP intake, nitrogen intake, and nitrogen excretion of Pekin ducks decreased (p < 0.05) due to different cage layers, while carcass characteristics remained unaffected by cage layer (p > 0.05). In summary, it is feasible to reduce the dietary CP level with crystalline amino acid supplementation in growing Pekin ducks from 21 to 42 days of age housed in cascading cages, while the cage layers affected growth performance of ducks. Based on broken-line models, it was determined that the optimal dietary CP requirement for achieving maximum weight gain and feed efficiency in growing Pekin ducks is approximately 15%. Full article

Prion diseases are fatal neurodegenerative disorders characterized by an accumulation of misfolded prion protein (PrP^Sc) in brain tissues. The shadow of prion protein (Sho) encoded by the shadow of prion protein gene (SPRN) is involved in prion disease progress. The interaction between Sho and PrP accelerates the PrP^Sc conversion rate while the SPRN gene polymorphisms have been associated with prion disease susceptibility in several species. Until now, the SPRN gene has not been investigated in ducks. We identified the duck SPRN gene sequence and investigated the genetic polymorphisms of 184 Pekin ducks. We compared the duck SPRN nucleotide sequence and the duck Sho protein amino acid sequence with those of several other species. Finally, we predicted the duck Sho protein structure and the effects of non-synonymous single nucleotide polymorphisms (SNPs) using computational programs. We were the first to report the Pekin duck SPRN gene sequence. The duck Sho protein sequence showed 100% identity compared with the chicken Sho protein sequence. We found 27 novel SNPs in the duck SPRN gene. Four amino acid substitutions were predicted to affect the hydrogen bond distribution in the duck Sho protein structure. Although MutPred2 and SNPs&GO predicted that all non-synonymous polymorphisms were neutral or benign, SIFT predicted that four variants, A22T, G49D, A68T, and M105I, were deleterious. To the best of our knowledge, this is the first report about the genetic and structural characteristics of the duck SPRN gene. Full article

This study evaluated duck growth, health, and welfare in response to water supplementation with organic acid (OA) and oregano oils (OOs) in Pekin duck. The treatments used in this study included a control (CON) treatment with no water additives given, an OA treatment (ProPhorce Exclusive NC^®), and an OO treatment (Nubiotic 4X Concentrate^®). The OA and OO improved the feed conversion ratio (FCR) and body weight (BW) (p < 0.01) compared to the control (CON). Both OA and OO showed differences (p < 0.05) in villus height and crypt depth compared to the CON. But only OA showed an increase (p < 0.01) in villus height and villus height/crypt depth ratio. On D 35, the total plasma corticosterone levels, heterophil-to-lymphocyte ratios, and asymmetry scores for OA and OO were decreased (p < 0.05) compared to CON, indicating lower stress susceptibility. The pH levels of OA ceca and jejunum were lower (p < 0.05) compared to CON. Tibia breaking strength was increased (p = 0.02) for OA compared to CON, while no differences were found with OO (p > 0.05). In conclusion, these experiments indicate that OA and OO can be used to improve duck growth, feed efficiency, stress susceptibility, and bird welfare. Full article

Subcutaneous fat deposition is an important index with which to evaluate meat-producing ducks, and affects their meat quality and feed conversion rate. Studying the differentially expressed genes in subcutaneous fat will help to comprehensively understand the potential mechanisms regulating fat deposition in ducks. In this study, 72 Nankou 1 Pekin Ducks and 72 Jingdian Pekin Ducks (half male and half female) at 42 days of age were selected for slaughter performance and transcriptome analysis. The results showed that the breast-muscle yield of Nankou 1 ducks was significantly higher than that of Jingdian ducks, but that the abdominal fat yield and subcutaneous fat yield were higher than that of Jingdian ducks. Thousands of DEGs, including many important genes involved in fat metabolism regulation, were detected by transcriptome. KEGG enrichment analysis showed that the DEGs were significantly enriched on pathways such as regulation of lipolysis in adipocytes, primary bile acid biosynthesis, and biosynthesis of unsaturated fatty acids. SCD, FGF7, LTBP1, PNPLA3, ADCY2, and ACOT8 were selected as candidate genes for regulating subcutaneous fat deposition. The results indicated that Nankou 1 had superior fat deposition ability compared to Jingdian ducks, and that the candidate genes regulated fat deposition by regulating fat synthesis and decomposition. Full article

China boasts a rich diversity of indigenous duck species, some of which exhibit desirable economic traits. Here, we generated transcriptome sequencing datasets of breast muscle tissue samples from 1D of four groups: Pekin duck pure breeding group (P), Jinling White duck breeding group (J), P ♂ × J ♀ orthogonal group (PJ) and J ♂ × P ♀ reciprocal-cross group (JP) (n = 3), chosen based on the distinctive characteristics of duck muscle development during the embryonic period. We identified 5053 differentially expressed genes (DEGs) among the four groups. Network prediction analysis showed that ribosome and oxidative phosphorylation-related genes were the most enriched, and muscular protein-related genes were found in the 14-day-old embryonic group. We found that previously characterized functional genes, such as FN1, AGRN, ADNAMST3, APOB and FGF9, were potentially involved in muscle development in 14-day-old embryos. Functional enrichment analysis suggested that genes that participated in molecular function and cell component and key signaling pathways (e.g., hippo, ribosome, oxidative phosphorylation) were significantly enriched in the development of skeletal muscle at 14 days of embryonic age. These results indicate a possible role of muscle metabolism and myoglobin synthesis in skeletal muscle development in both duck parents and hybrids. Full article