The precise targeted integration of large exogenous genes into chicken sex chromosomes is of particular interest for sex-linked trait manipulation, sex-control breeding, and the development of avian bioreactor models. However, efficient targeted integration at sex chromosome loci remains technically challenging, and optimized editing strategies for these loci are still lacking. To improve targeted genome editing at two previously identified chicken sex chromosome safe-harbor loci, EE0.6 and NC_006127.4, this study systematically evaluated and optimized key parameter affecting editing efficiency. First, we evaluated the effects of different sgRNA combinations on targeted knockout efficiency, establishing the advantage of a dual-sgRNA/Cas9 architecture, which achieved knockout efficiencies of 86.67% and 75.00% at the EE0.6 and NC_006127.4 loci, respectively. We next introduced the Cas9 nickase (Cas9n) system, which has previously been reported to exhibit improved editing specificity, and evaluated its performance at both target loci. Quantitative analysis showed that the dual-sgRNA/Cas9 targeting system successfully mediated the precise targeted integration of a 1.1-kb SV40-mCherry reporter cassette, reaching 100% (28/28) at the EE0.6 locus and 80.00% (20/25) at the NC_006127.4 locus. Based on this result, this study further investigated the effects of donor homology arm (HA) lengths (200 bp, 600 bp, and, 1000 bp) and vector topologies (circular and linearized) on targeted knock-in efficiency. The results revealed that in the circular donor system, the optimal HA lengths for the EE0.6 and NC_006127.4 loci were 200 bp (50.4% ± 4.4%) and 600 bp (30.1% ± 1.2%), respectively. However, upon the introduction of linearized donors with free ends, the knock-in efficiency of the exogenous target fragment was significantly enhanced, and its HA length preference underwent a significant reversal. The optimal HA length for EE0.6 was extended to 600 bp (78.9% ± 1.0%), whereas that for NC_006127.4 was shortened to 200 bp (49.9% ± 0.4%). In summary, this study established an efficient targeted integration strategy for chicken sex chromosome loci. The optimized system provides a foundation for future applications in sex-linked breeding and avian bioreactor development.

Sex determination is a crucial process in animal development, regulated by complex genetic networks. In avian species, Doublesex and mab-3 related transcription factor 1 (DMRT1) plays a vital role in gonadal development and sex determination. To unravel the function of DMRT1 in chicken sex determination, establishing an inducible DMRT1 knockout model is essential. In this study, we constructed an inducible DMRT1 knockout system and verified its efficiency and effects on related genes and physiological indicators. To achieve precise genomic ablation, we screened multiple sgRNAs targeting the DMRT1 locus and integrated the optimal sequence into a doxycycline-responsive (Tet-on) CRISPR/Cas9 architecture. For in vitro experiments, vectors were delivered via cell transfection and induced with 20 µg mL-1 doxycycline (DOX), achieving an 80% knockout efficiency. Following the administration of polyethylenimine (PEI)-encapsulated plasmids into chicken embryos, we successfully implemented the inducible system in vivo. Quantitative analysis confirmed a mosaic knockout of DMRT1 with an observed efficiency reaching 45%. Following targeted disruption, we evaluated sex-related gene and protein expression alterations via qRT-PCR and Western blot (WB). Furthermore, ELISA was performed to measure testosterone levels in male embryonic gonads across multiple developmental stages (E4.5 to E18.5). qRT-PCR analysis showed that after induction, female-related genes (CYP19A1, FOXL2, ESR1) were significantly upregulated, and male-related genes (DMRT1, SOX9, AMH) were significantly downregulated. WB results revealed increased protein expression levels of CYP19A1 and FOXL2, and decreased protein expression of SOX9 post-induction. ELISA confirmed that testosterone levels in the gonads of induced male embryos were significantly reduced compared to normal and non-induced males. The study successfully established an inducible DMRT1 knockout system in chickens. This system effectively regulates the expression of sex-related genes and reduces testosterone levels in male embryos, providing theoretical and technical support for breeding novel sex-controlled breeding materials.

Goose eggs are an important avian food source with higher lipid and protein content than chicken or duck eggs, but their relatively high unsaturated fat level makes them more prone to oxidation and quality deterioration during storage. Although metabolomics has been widely applied in meat science, information on changes in non-volatile metabolites during the refrigerated storage of goose eggs remains limited. Using a non-targeted metabolomics approach, this study systematically characterized the dynamic metabolic profiles of goose eggs during refrigeration. Machine learning algorithms were further integrated to screen potential marker metabolites and to identify key metabolic pathways associated with goose egg spoilage. Temporal trend analysis was performed using Mfuzz clustering to characterize metabolite dynamics across different storage stages. After variance analysis, a total of 52 consistently upregulated and 47 consistently downregulated differential metabolites were identified. Pathway enrichment analysis indicated that purine metabolism, pyrimidine metabolism, and tyrosine metabolism may play central regulatory roles during the spoilage process of goose eggs. Furthermore, four potential spoilage biomarkers—3-hydroxybutanoic acid, 6-aminonicotinamide, Gly-His, and maleic acid—were identified through random forest and LASSO regression analysis. These findings elucidate the key metabolic pathways associated with protein/lipid oxidation during goose egg refrigeration and establish a metabolite signature-based prediction framework for goose egg freshness to achieve accurate identification of early-stage spoilage.

The source and mechanism of goose egg flavor formation remain unclear. A comprehensive investigation was conducted to elucidate the dynamic metabolic alterations and the mechanisms underlying flavor formation in the albumen of Taihu goose eggs during storage at 4 °C (Days 1, 15, 30, and 60). A total of 761 metabolites from 16 categories were identified by LC-MS/MS-based metabolomic analysis, with amino acids and derivatives being the predominant class. A total of 384 differential metabolites were screened and determined for their dynamic changes under low-temperature storage, with 74.5% of metabolites increasing and 25.5% decreasing over time, highlighting storage as a critical factor shaping the albumen metabolome. Enrichment analysis identified key metabolic pathways, including D-amino acid metabolism, amino acid biosynthesis, phenylalanine metabolism, and aminoacyl-tRNA biosynthesis. This work provides a crucial theoretical foundation for improving storage practices and enhancing the quality and flavor of goose eggs.

Optimizing the dietary fatty acid profile has been recognized as an effective strategy for improving meat quality traits in poultry. The present study aimed to investigate how different dietary n-6/n-3 polyunsaturated fatty acids (PUFAs) ratios influence hepatic fatty acid composition and gut microbiota in ducks, and to identify key microorganisms involved in gut-liver axis regulation. In this study, Runzhou white-crowned ducks were used as a model to explore the effects of dietary n-3 PUFAs content on liver fatty acid composition and intestinal microbiota, and to screen out key microorganisms that mediate gut-liver axis signaling. A total of 112 28-day old Runzhou white- crowned ducks fed with 2 types of diets (with n-6/n-3 PUFA ratios of 1.97 and 17.37) were randomly divided into 2 treatments with 4 replications (14 ducks per replication) for 28 days. A low n-6/n-3 PUFA ratio significantly increased hepatic n-3 PUFA levels (P < 0.05) while reducing n-6 PUFA synthesis. High-throughput 16S rRNA sequencing showed that n-3 PUFA supplementation altered the microbial composition in both the cecum and colon. It also supported intestinal development by maintaining villus structure and overall gut integrity. At the genus level, Bacteroides were enriched in the cecum (P < 0.05), whereas in the colon, n-3 PUFA increased Campylobacter abundance and reduced Pseudomonas. Using a random forest model, 20 and 50 key microbial taxa were identified in the cecal and colonic communities, respectively. Integration with Spearman correlation analysis revealed strong associations between hepatic n-3 PUFA levels and microbial changes. Notably, Caecibacterium_sporoformans showed a positive correlation with multiple n-3 PUFAs, and its abundance in both the cecum and colon increased significantly (P < 0.05). In summary, a low dietary n-6/n-3 PUFA ratio promoted hepatic n-3 PUFA accumulation, reshaped gut microbial communities, and supported intestinal health, highlighting the gut-liver axis as a key pathway for nutritional regulation in ducks.

This study combined lipidomics technology with machine learning models to identify differences in intermuscular fat (IMF) between goose breeds and to screen for key lipid molecules. Here, we compared the meat quality characteristics and IMF lipid profiles of two goose breeds. The results showed that the meat quality traits of Yangzhou goose (YG) and Zhedong white goose (ZG) exhibited significant breed-specific differences, particularly in muscle color and physical properties. Using UPLC-ESI-MS/MS, we established a comprehensive lipid profile of YG and ZG breast muscles, identifying 35 lipid subclasses encompassing 564 lipid molecules. Based on the lipid dataset, we performed OPLS-DA analysis and identified 328 differential lipids. Further bioinformatics analysis showed that lipid deposition in YG and ZG was primarily influenced by glycerophospholipid and glyceride metabolic pathways, respectively. Subsequently, we used supervised PCA models and unsupervised machine learning models to screen characteristic lipids, and took the intersection of multiple models. Finally, we identified 8 key characteristic lipids to evaluate the differences in IMF between the two goose meats. These results show that the combination of lipidomics and machine learning not only reveals the dynamic changes of lipid molecules in complex biological samples, but also offers valuable insights for goose meat quality evaluation and biomarker screening.

This study utilized the O2PLS model to successfully integrate multidimensional data from meat quality traits and quantitative lipidomics, identifying key lipids involved in lipid deposition in goose meat. Meat quality analysis showed higher intramuscular fat content in goose meat during the sexual maturity phase. Lipidomics techniques were subsequently applied to elucidate differences in breast muscle lipid profiles between the growth phase and sexual maturity phase. Using UPLC-ESI-MS/MS, 298 lipids were identified as significantly altered. Unsupervised principal component analysis was employed to identify characteristic lipids distinguishing the two stages. As expected, phospholipids emerged as the key metabolites differentiating developmental stages, with three phospholipids identified in growth phase and five in sexual maturity phase. Finally, the O2PLS model revealed that characteristic lipids PE-P(P-16:0_18:1), PC(O-16:1_20:4), LPC (22:6), and SMs(d18:1/19:0) were significantly positively correlated with fat deposition in goose meat. Collectively, these findings offer new insights into the mechanisms of intramuscular fat deposition in goose meat and provide potential molecular targets for improving meat quality through dietary or breeding strategies.

Goose is one of the most economically valuable poultry species and has a distinct appearance due to its possession of a knob. A knob is a hallmark of sexual maturity in goose (Anser cygnoides) and plays crucial roles in artificial selection, health status, social signaling, and body temperature regulation. However, the genetic mechanisms influencing the growth and development of goose knobs remain completely unclear. In this study, histomorphological and transcriptomic analyses of goose knobs in D70, D120, and D300 Yangzhou geese revealed differential changes in tissue morphology during the growth and development of goose knobs and the key core genes that regulate goose knob traits. Observation of tissue sections revealed that as age increased, the thickness of the knob epidermis, cuticle, and spinous cells gradually decreased. Additionally, fat cells in the dermis and subcutaneous connective tissue transitioned from loose to dense. Transcriptome sequencing results, analyzed through differential expression, Weighted Gene Co-expression Network Analysis (WGCNA), and pattern expression analysis methods, showed D70-vs.-D120 (up-regulated: 192; down-regulated: 423), D70-vs.-D300 (up-regulated: 1394; down-regulated: 1893), and D120-vs.-D300 (up-regulated: 1017; down-regulated: 1324). A total of 6243 differentially expressed genes (DEGs) were identified, indicating varied expression levels across the three groups in the knob tissues of D70, D120, and D300 Yangzhou geese. These DEGs are significantly enriched in biological processes (BP) such as skin morphogenesis, the regulation of keratinocyte proliferation, and epidermal cell differentiation. Furthermore, they demonstrate enrichment in pathways related to goose knob development, including ECM–receptor interaction, NF-kappa B, and PPAR signaling. Through pattern expression analysis, three gene expression clusters related to goose knob traits were identified. The joint analysis of candidate genes associated with goose knob development and WGCNA led to the identification of key core genes influencing goose knob development. These core genes comprise WNT4, WNT10A, TCF7L2, GATA3, ADRA2A, CASP3, SFN, KDF1, ERRFI1, SPRY1, and EVPL. In summary, this study provides a reference for understanding the molecular mechanisms of goose knob growth and development and provides effective ideas and methods for the genetic improvement of goose knob traits.

The quality (color, tenderness, juiciness, protein content, and fat content) of poultry meat is closely linked to age, with older birds typically exhibiting increased intramuscular fat (IMF) deposition. However, specific lipid metabolic pathways involved in IMF deposition remain unknown. To elucidate the mechanisms underlying lipid changes, we conducted a study using meat geese at 2 distinct growth stages (70 and 300 d). Our findings regarding the approximate composition of the meat revealed that as the geese aged 300 d, their meat acquired a chewier texture and displayed higher levels of IMF. Liquid chromatography-mass spectrometry (LC-MS) was employed for lipid profiling of the IMF. Using a lipid database, we identified 849 lipids in the pectoralis muscle of geese. Principal component analysis and orthogonal partial least squares discriminant analysis were used to distinguish between the 2 age groups and identify differential lipid metabolites. As expected, we observed significant changes in 107 lipids, including triglycerides, diglycerides, phosphatidylethanolamine, alkyl-glycerophosphoethanolamine, alkenyl-glycerophosphoethanolamine, phosphatidylcholine, phosphatidylinositol, lysophosphatidylserine, ceramide-AP, ceramide-AS, free fatty acids, cholesterol lipids, and N-acyl-lysophosphatidylethanolamine. Among these, the glyceride molecules exhibited the most pronounced changes and played a pivotal role in IMF deposition. Additionally, increased concentration of phospholipid molecules was observed in breast muscle at 70 d. Unsaturated fatty acids attached to lipid side chain sites enrich the nutritional value of goose meat. Notably, C16:0 and C18:0 were particularly abundant in the 70-day-old goose meat. Pathway analysis demonstrated that glycerophospholipid and glyceride metabolism were the pathways most significantly associated with lipid changes during goose growth, underscoring their crucial role in lipid metabolism in goose meat. In conclusion, this work provides an up-to-date study on the lipid composition and metabolic pathways of goose meat and may provide a theoretical basis for elucidating the nutritional value of goose meat at different growth stages.

随着人民生活水平的不断提高以及城市化进程的加快,鸡肉消费在全社会肉品消费的比重不断攀升,已是继猪肉之后的第二大消费肉品,俨然畜牧业已成为国民经济的重要支柱产业.本文主要对白羽肉鸡的饲养管理技术进行了阐述,在当前实施乡村振兴战略的大环境下我们对白羽肉鸡养殖的关键技术(从消毒、温度、湿度、通风)进行了梳理,并指出了其发展的方向.

China has a rich genetic resource in its 34 domestic duck breeds. In order to detect the genetic diversity and explore the origin of these indigenous duck populations, the mitochondrial DNA (mtDNA) control region was sequenced and analyzed for 208 individual ducks, including 22 domestic breeds, wild Mallards ducks, Eastern spot-billed ducks, White Muscovy ducks, and Black Muscovy ducks. The haplotype diversity (Hd) was 0.653 and the average nucleotide diversity (Pi) was 0.005, indicating moderate genetic diversity. Sixty haplotypes were detected, and the maximum-likelihood (ML) phylogenetic tree and median-joining (MJ) network were generated from the sequence analyses. In this study, haplotypes from the Mallard duck (Anas platyrhynchos) were detected in most of the Chinese domestic duck breeds. In addition, the Eastern spot-billed duck (A. zonorhyncha) H8 haplotype was detected in two duck breeds. Only two haplotypes were found in Muscovy ducks, suggesting low genetic diversity within this population. The sequence and haplotype analyses revealed that both A. platyrhynchos and A. zonorhyncha contributed to the evolution of domestic ducks in China.

The development of the knob in Chinese geese (Anser cygnodies) is an outcome of extensive and prolonged selection and breeding. The knob serves not only as a visual indicator of sexual maturity in geese but also holds significance as a crucial packaging trait that attracts attention of consumers attentions, who tend to distinctly prefer geese with larger knobs. Consequently, investigating the formation of the knob holds practical value, as it will help achieving external traits aligned with consumers’ preferences. To understand the relationship between knob size, production efficiency, and meat quality in Yangzhou geese, we examined histological and anatomical characteristics in 500- and 120-day-old geese with large and small knobs. Notably, knob size had a pronounced impact on key anatomical and structural parameters, such as chest depth, leg muscle water-binding capacity, and insoluble collagen composition in Yangzhou geese (p < 0.05). In addition, we measured testosterone and estrogen levels in male and female geese, respectively, as well as growth hormone, and found that birds of both sexes with a large knob had higher sex and growth hormone levels in the body. This study established a fundamental theoretical basis for advancing the enhancement of goose knob traits.

脂质组学是以脂质为对象,通过分析不同生理状态下体内脂质分子的变化情况,识别代谢调控途径中关键的脂质标志物,从而阐明单个脂质分子对脂质代谢与机体功能的影响.目前,随着脂质组学技术的发展,其已被广泛应用于畜禽生产当中,在脂肪沉积、乳脂代谢、营养调控以及性能测定等方面具有重要作用.本文主要综述了脂质组学技术以及其在畜禽脂质代谢研究中的应用,并简要分析了畜禽脂质代谢差异的可能原因,以期为阐明畜禽的脂质代谢提供参考.

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.

蒙脱石是一种层状硅酸盐黏土,对细菌、重金属、霉菌毒素和细菌毒素等具有良好的吸附作用,且可修复和保护肠道黏膜.蒙脱石对病原体应激下的动物肠道屏障具有显著保护作用,饲粮添加蒙脱石能改善动物肠黏膜形态、促进肠上皮细胞紧密连接蛋白和黏蛋白表达、优化肠道菌群结构、调节肠黏膜免疫功能,是一种颇具潜力的动物肠道健康调节剂.本文综述了蒙脱石对动物肠道健康影响的研究进展,总结了蒙脱石调控动物肠道屏障功能的可能机制,以期为动物肠道健康营养调控提供参考.