RETRACTED: Growth performance, carcass characteristics, and selected meat quality traits of two strains of Pekin duck reared in intensive vs semi-intensive housing systems

Carcass traits, proximate composition, amino acid and fatty acid profiles, and mineral contents of meat from Cherry Valley, Chinese crested, and crossbred ducks

Duck meat is known for its taste and high nutritive value. To preserve local genetic diversity while maintaining commercial viability, we obtained a crossbreed (CB) between high-performing Cherry Valley (CV) and traditional Chinese crested (CC) ducks. We compared carcass traits and meat quality characteristics of CB and parental breeds. Meat from the above ducks at their respective marketable ages was evaluated for proximate composition, amino acid and fatty acid profiles, and selected mineral content. The live weights, carcass weights, and breast muscle percentage of CB were higher than CC but lower than CV; the leg muscle of CB was lower than CV and CC. CB had higher intramuscular fat content than CV; its collagen content was lower than CC but higher than CV in breast and thigh muscles. Additionally, the saturated fatty acid content of CB muscle was lower than CV and higher than CC. CB contained more monounsaturated fatty acids than CV and CC. Zn content was higher in CB breast than CV and CC. CB, obtained by crossing CV and CC, has partial advantages over both the breeds suggesting that these characteristics aligned with standards to breed ducks with high-quality meat.

Effects and Mechanisms of Cage versus Floor Rearing System on Goose Growth Performance and Immune Status

Currently, FRS and CRS are the two predominant dryland rearing systems in the goose industry. However, the effects of these two systems on goose growth performance and health, as well as the underlying mechanisms, have not been fully clarified. Thus, this study aimed to compare growth performance and immune status, as well as investigate the genome-wide transcriptomic profiles of spleen in geese, between CRS and FRS at 270 d of age. Phenotypically, the body weight and body size traits were higher in geese under FRS, while the weight and organ index of spleen were higher in geese under CRS (p < 0.05). Noticeably, the bursa of Fabricius of geese under FRS was degenerated, while that under CRS was retained. At the serum level, the immune globulin-G (IgG) and interleukin-6 (IL-6) levels were higher in geese under CRS (p < 0.05). At the transcriptomic level, we identified 251 differentially expressed genes (DEGs) in the spleen between CRS and FRS, which were mainly enriched in scavenger receptor activity, inflammatory response, immune response, neuroactive ligand-receptor interaction, phenylalanine metabolism, ECM receptor interaction, calcium signaling pathway, phenylalanine, tyrosine, and tryptophan biosynthesis, regulation of actin cytoskeleton, and MAPK signaling pathways. Furthermore, through protein-protein interaction (PPI) network analysis, ten candidate genes were identified, namely, VEGFA, FGF2, NGF, GPC1, NKX2-5, FGFR1, FGF1, MEIS1, CD36, and PAH. Further analysis demonstrated that geese in CRS could improve their immune ability through the "phenylalanine metabolism" pathway. Our results revealed that the FRS improved growth performance, whereas the CRS improved goose immune function by increasing levels of IL-6 and IgG in serum. Moreover, the phenylalanine metabolism pathway could exert positive effects on immune function of geese under CRS. These results can provide reliable references for understanding how floor and cage rearing systems affect goose growth performance and immune capacity.

Analysis of growth performance and carcass and meat quality of different crossbreeds of Cherry Valley duck

Duck breeding and production are facing great opportunities in China, as the market for small-sized high-quality duck is rapidly expanding. Therefore, breeding the most suitable genetic stock has become an important goal.This study assessed body and carcass weight, slaughter rate and meat quality of offspring of three cross combinations; Cherry Valley duck (CV♂) × Small-sized Pekin duck (PK♀), CV♂×Taiwan white duck (TW♀), CV♂×Putian white duck (PT♀) and the corresponding pure lines at 56 d of age. These 420 ducks were raised in seven separate groups (10 pens/group, 3♂+3♀/pen).Body and carcass weights were significantly lower in the three cross combinations than CV ducks (P=0.042 and P=0.012). Abdominal fat and sebum weight were lowest in CV♂×PK♀, whereas the breast and the leg muscle weights were significantly higher in CV♂×PK♀ compared to CV♂×TW♀ and CV♂×PT♀ (P=0.018 and P=0.023). No difference was observed in the visceral tissues among the three cross combinations or compared to CV ducks.The performance indicators suggested that CV♂×PK♀, CV♂×TW♀ and CV♂×PT♀ cross combinations are best suited for segmented duck meat, featured duck meat and whole-duck processing, respectively.

Identification of the Differentially Expressed Genes in the leg muscles of Zhedong White Geese (Anser cygnoides) reared under different photoperiods

Light is a factor affecting muscle development and meat quality in poultry production. However, few studies have reported on the role of light in muscle development and meat quality in geese. In this experiment, 10 healthy 220-day-old Zhedong white geese were reared for 60 d under a long photoperiod (15L:9D, LL) and short photoperiod (9L:15D, SL). The gastrocnemius muscles were collected after slaughter to evaluate muscle fiber characteristics and meat color, and RNA-seq analysis. The results showed that compared to the LL group, the SL group had large muscle fiber diameter and cross-sectional area, few muscle fibers per unit area, high meat color a* value, and low L* value at 24 h postmortem. On comparing the 2 groups, 70 differentially expressed genes (DEGs) were identified. Compared to the SL group, the LL group had 25 upregulated and 45 downregulated genes. Gene Ontology (GO) enrichment analysis showed that these DEGs were mainly involved in cell, cell part, binding, cellular processes, and single-organism processes. Several significantly enriched athways were identified in the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, such as the calcium and PI3k-Akt signaling pathways. The expression of five randomly selected DEGs was verified using quantitative real-time PCR, and the results were consistent with the RNA-seq data. This study provides a theoretical basis for studying the molecular mechanisms by which light affects muscle development and meat color in geese.

The Composition of the Carcass, Physicochemical Properties, Texture and Microstructure of the Meat of D11 Dworka and P9 Pekin Ducks

The aim of the study was to determine the effects of genotype and sex on carcass composition and selected meat quality parameters of Dworka and Pekin ducks after two reproductive seasons. The research material consisted of 24 carcasses of Dworka ducks (breeding strain D11) and 24 carcasses of Pekin ducks from the herd of genetic resources (French Pekin, strain P-9). After cooling the carcasses (18 h, 2 °C), the pH values and electrical conductivity of the pectoral and leg muscles were determined, and then the carcass was dissected using a simplified method. After dissection, the pectoral and leg muscles were sampled for quality characteristics assessment. The Dworka ducks from breeding strain D11 compared to Pekin duck from conservative strain P9 were characterized by significantly (p < 0.05) higher carcass weight, protein and salt content, thermal drip, yellowness, thickness of perymisium and endomysium and lower water content of the pectoral muscle. Dworka ducks were also characterized by higher protein, salt and collagen content and higher electrical conductivity (EC24) of leg muscles than Pekin ducks. Regardless of genotype, male ducks had a higher gutted carcass weight with neck, salt content, muscle fiber cross-sectional area, fiber perimeter and diameters of pectoral muscle, and also higher protein and collagen, and lower fat content, pH24 and electrical conductivity of leg muscles. The genotype by sex interaction was significant (p < 0.05) for water, protein, fat content, perimisium thickness, cohesiveness, springiness of the pectoral major muscle, and for water content and protein of the leg muscles. The results obtained in this study demonstrate the effects of genotype and sex on the nutritional value and some technological parameters of duck meat. The studied ducks after two reproductive seasons satisfactorily meet the requirements of duck meat for consumers and duck meat processing plants.

Genome-Wide Association Study of Potential Meat Quality Trait Loci in Ducks

With continuously increasing living standards and health requirements of consumers, meat quality is becoming an important consideration while buying meat products. To date, no genome-wide association study (GWAS) for copy number variants (CNVs) and single nucleotide polymorphisms (SNPs) has been conducted to reveal the genetic effects on meat quality in ducks. This study analyzed the phenotypic correlation and heritability of fat, water, collagen, and protein content of duck breast muscle. To identify the candidate variants for meat quality, we performed a GWAS using 273 ducks from an F2 population. The results of the SNP GWAS showed that the BARHL2, COPS7B, and CCDC50 genes were associated with fat content; BLM, WDR76, and EOMES with water content; CAMTA1, FGD5, GRM7, and RAPGEF5 with collagen production; and RIMS2, HNRNPU, and SPTBN1 with protein content. Additionally, 3, 7, 1, and 3 CNVs were associated with fat, water, collagen, and protein content, respectively, in duck breast muscle. The genes identified in this study can serve as markers for meat quality. Furthermore, our findings may help devise effective breeding plans and selection strategies to improve meat quality.

Effects of cage versus floor rearing system on goose intestinal histomorphology and cecal microbial composition

Due to the demand for modern goose production and the pressure of environmental protection, the rearing systems of geese are changing from traditional waterside rearing to intensive rearing systems such as floor rearing (FR) and cage rearing (CR) systems. However, little is known about the effects of different rearing systems on goose intestinal functions and cecal microbial composition. Therefore, this study aimed to compare intestinal histomorphology and cecal microbial composition differences in geese reared under CR and FR at 270 d of age. Histomorphological analysis showed that the ileal villus height (VH) to crypt depth (CD) ratio was significantly greater in CR than in FR (P < 0.001). Taxonomic analysis showed that the dominant bacteria of cecal microorganisms in both rearing systems were roughly similar, with Bacteroidota, Firmicutes, Fusobacteriota, and Proteobacteria being the dominant phyla while Bacteroides, Fusobacterium, and uncultured_bacterium_o_Bacteroidales being the dominant genera. Differentially abundant taxa between CR and FR were also identified using Linear Discriminant Analysis Effect Size (LEfSe) analysis (P < 0.05, LDA score > 3.5). Megamonas and Anaerobiospirillum were significantly enriched in the CR group at the genus level, while uncultured_bacterium_f_Rikenellaceae and Sutterella were significantly enriched in the FR group. Notably, we found that the relative abundance of uncultured_bacterium_f_Rikenellaceae was significantly negatively correlated with the ileal VH and VH/CD (P < 0.05). The relative abundance of Megamonas and Anaerobiospirillum were significantly negatively correlated with abdominal fat weight and relative abdominal fat weight (P < 0.01), whereas that of Sutterella was significantly positively correlated with abdominal fat weight and relative abdominal fat weight (P < 0.01). Furthermore, PICRUSt2 analysis indicated that the lipid metabolism pathways of cecal microorganisms were lower enriched in CR than in FR. In conclusion, compared with FR, the CR significantly changed goose ileal histomorphological characteristics and cecal microbial composition, thereby affecting goose physiological functions and production performance.

Research Note: Effects of cage and floor rearing systems on growth performance, carcass traits, and meat quality in small-sized meat ducks

This study was performed to evaluate the effects of different rearing methods on the growth performance, carcass yield, and meat quality of small-sized meat ducks. A total of 420 healthy 21-day-old birds was randomly allocated to 2 treatment groups (6 replicates per treatment, sex ratio 1/1) and subjected to 2 rearing methods (furnished cage and plastic wire-floor) until d 63. Growth performance was measured in all birds. Three males and 3 females from each replicate were randomly selected and evaluated to determine the carcass yield and meat quality. In terms of growth performance, the rearing method affected the final body weight, average daily feed intake, and average daily gain, which were higher in the cage group (P < 0.05) than in the floor group, with a similar feed/gain in both groups. For slaughter performance, ducks in the cage group showed a higher abdominal fat yield and lower gizzard yield than those in the floor group (P < 0.05). For meat quality, the L* value of the breast muscle was higher in the cage group than in the floor group (P < 0.05). The pH recorded at 1 h was lower and pH recorded at 24 h was higher in the cage group (P < 0.05). The shear force and water loss rate were both lower in the cage group (P < 0.05). Additionally, the moisture content was lower and intramuscular fat content was higher in ducks fed in cages (P < 0.05). Our results indicate that the cage rearing system improved the growth performance and meat quality of ducks, which is appropriate for small-sized meat ducks.