The objective was to determine the effects of supplementing duck diets with Eucommia ulmoides oliv. leaf powder (EUL). Laying ducks (n = 480) were randomly allocated into 4 experimental treatments and fed diets containing 0, 1, 2, or 4% EUL. Dietary inclusion of EUL had no effect (p > 0.05) on laying performance or egg quality, but linearly increased (p < 0.05) total plasma protein, globulin, and HDL-C concentrations with concurrent reductions (p < 0.05) in plasma concentrations of cholesterol and LDL-C. Eggs laid by ducks receiving EUL had yolks with linearly higher phenolic concentrations (p < 0.05) but lower cholesterol concentrations (p < 0.05). EUL supplementation in duck diets significantly reduced n-6: n-3 PUFA ratio by enriching n-3 fatty acids in yolks (p < 0.05) with no changes in n-6 PUFA (p >0.05).

Puan Panjiang black-bone chickens are renowned for their distinctive traits, deep black coloration, and high-quality protein content, making them a focus of genetic research due to their unique egg-laying abilities. In this study, 110 Puan Panjiang black-bone chickens were used to investigate the effects of natural and artificial selection influencing egg production. Whole-genome resequencing data from red junglefowl (RJF) and high-egg-production (HEP) and low-egg-production (LEP) groups of Puan Panjiang black-bone chickens revealed significant genetic variants associated with egg production traits. Additionally, transcriptome analysis of 47 samples from ovary stroma, small white follicles (SWFs), small yellow follicles (SYFs), and liver tissues from 6 HEP and 6 LEP groups identified differentially expressed genes. Notably, differences in egg production were linked to small yellow follicles rather than ovary stroma or SWFs. Key candidate genes, including TRIM7, CASR, SPTBN5, GAL1, ZP1, IL4I1, and CCL19, were identified as potential contributors to egg-laying performance. This study underscores the genetic diversity within this breed and provides valuable insights for future breeding programs to enhance egg production, supporting the sustainable development of this local resource.

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%.

The aim was to investigate effects of various proportions (0 to 20%) of fermented rapeseed meal (FRSM) on performance, intestinal health, and antioxidant status in Sansui ducks (Sansui Sheldrake ducks). A total of 350 male ducklings, 15 d old, were allocated into five dietary treatments with seven replicate pens of 10 birds per pen. The starter diets had 0, 5, 10, 15, or 20% FRSM that contained 0, 1.08, 2.17, 3.25, or 4.34 µmol glucosinolates (GLS/g of complete feed, respectively, fed from d 15 to d 35. The average daily feed intake (ADFI) and feed conversion ratio (FCR) from d 15 to 35 increased linearly with the dietary FRSM inclusion, with the ducks fed 15 or 20% FRSM diets having higher (p < 0.05) ADFIs and FCRs than the ducks fed 0% FRSM. The dietary FRSM inclusion levels of up to 15% were accompanied by decreased catalase (CAT) and antioxidant capacity (AOC) activities in the livers and jejunum of the ducks at d 35. In addition, the 20% FRSM (4.34 µmol GLS/g diet) decreased the villus height, crypt depth, muscular thickness, and goblet cell counts in the jejunum and ileum. In conclusion, 15 or 20% dietary FRSM (3.25 or 4.34 µmol GLS/g diet) during the grower period in Sansui ducks decreased feed efficiency, disrupted hepatic antioxidant balance, and impaired intestinal morphology and structure. The FRSM inclusion of ≥15% (3.25 µmol glucosinolates/g) impaired feed efficiency and antioxidant activity, while the 20% FRSM (4.34 µmol glucosinolates/g) induced intestinal damage in the growing Sansui ducks.

Duck meat is highly appreciated for its unique flavor and rich nutritional value, and metabolites have become important phenotypic indicators of meat quality. The Sansui duck, a celebrated local breed from Guizhou, is known for its tender, savory meat, yet its metabolomic composition and underlying genetic basis remain unexplored. In our study, non-targeted LC-MS/MS metabolomics of 305 Sansui duck breast muscles detected 4,729 metabolic features (459 annotated) and identified 136 sex-differential metabolites enriched in fatty acid and amino acid metabolism pathways. Metabolite-based genome-wide association studies (mGWAS) further identified 355 significant LD-independent SNPs and 267 potential candidate genes associated with 103 metabolites. The signal peaks for amino acid metabolites were mainly concentrated on chromosomes 1, 5, and 20. A QTL on chromosome 2 (63.90-64.10 Mb), containing candidate genes ZNF407, CNDP1, and CNDP2, was identified for three methylglyoxal derivatives, with the lead SNP (chr2: 63928783) accounting for about 18.3 % of their variance. Additional QTLs on chromosomes 5, 20, 1, and 24 were associated with Carnosine, N-Acetylhistidine, Acetylcholine, N-Acetyl-L-aspartic acid, 11b-PGF2a, and 12(S)-HpETE. These intervals harbor BBOX1 and ACACA, two key rate-limiting enzymes in fatty acid metabolism. Our results revealed the genetic basis of breast muscle metabolites in Sansui ducks and identified associated genetic loci and candidate genes. These findings deepen our understanding of muscle metabolism and provide valuable insights for improving meat quality and nutritional breeding.

This study evaluated the effects of dietary perilla seed meal (PSM) inclusion on growth performance, plasma biochemistry, and breast muscle fatty acid composition in Sansui ducks (Sansui Sheldrake ducks) from 4 to 8 wks of age. A total of 320 male ducks, 29 d old, were randomly assigned to 5 dietary treatments (0, 5%, 10%, 15%, or 20% PSM) with 8 replicates each group and 8 ducks per replicate. Results showed that PSM inclusion up to 20% did not significantly (p > 0.05) affect body weight, daily gain, feed intake, feed-to-gain ratio, or carcass traits. Plasma albumin, total cholesterol, and high-density lipoprotein cholesterol were elevated at 10% PSM inclusion (p < 0.05), while liver function markers remained unaffected (p > 0.05). As expected, dietary PSM supplementation dose-dependently enriched breast muscle n-3 polyunsaturated fatty acids, including α-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid (p < 0.05), and reduced the n-6/n-3 ratio (p < 0.05). These findings indicated that PSM could be incorporated into duck diets at levels up to 20% to enhance the nutritional value of duck meat without adverse effects on growth performance and health, supporting its use as a functional feed ingredient in sustainable duck production.