Medium-chain monoglycerides (MG) have been reported to affect the productive performance, gut microbiota and health of broiler chickens reared in ideal experimental conditions at home and abroad. However, the effects of MG on performance, intestinal development and gut microbiota of chickens in large-scale farms during different feed stages remain unknown. The present study was conducted on a modern farm with a total of 12,000 yellow feathered broiler chicks that were randomly allotted to 2 groups (1000 chicks/replicate, 6 replicates/group) for a 70-day trial. The control group (CON group) received a basal diet, and the treated group (MG group) was fed a basal diet containing 300 mg/kg mixed MG. The results revealed that dietary MG significantly (P < 0.05) increased the body weight and average feed intake, but notably reduced the feed conversion and mortality of chickens in large-scale production during the starter phase. The villus height of the duodenum in the MG group at 1, 2 and 7 wk of age increased notably, and the villus height to crypt depth ratio at 1, 2, 5 and 10 wk of age was improved. Dietary MG decreased the serum insulin content of chickens at 5, 7 and 10 wk of age, and decreased the serum lipopolysaccharide at 3 and 7 wk of age. The triglyceride level of chickens at 3, 5 and 10 wk of age and the low-density lipoprotein cholesterol level of chickens at 7 and 10 wk of age in the MG group decreased notably, while the high-density lipoprotein cholesterol increased significantly. Moreover, MG supplementation selectively increased the relative abundance of genus Bacteroides (family Bacteroidaceae) and Lachnospiraceae_NK4A136_group, but decreased the content of genus Rikenellaceae_RC9_gut_group, Collinsella and family Barnesiellaceae in the cecum of chickens at 3, 7 and 10 wk of age. Conclusively, these findings showed that dietary MG notably enhanced chicken performance, health and feed nutrient utilization at early ages by regulating gut microbiota, intestinal development and serum biochemical indices.

Chicken muscle yield and amino acid composition improvements with medium-chain monoglyceride (MG) supplementation were reported by previous studies, but the underlying mechanism was uncertain. This study aimed to decipher chicken amino acid improvements induced by medium-chain monoglycerides in the views of metabolomics, gene expression, and the gut microbiome. Newly hatched chicks (12,000 chicks) were weighed and randomly divided into two flocks, each with six replicates (1000 chicks per replicate), and fed a basal diet (the control group, CON) or a basal diet enriched with 300 mg/kg MG (the treated group, MG). Results demonstrated that MGs significantly increased the chicken flavor and essential and total amino acids. The serum amino acids and derivatives (betaine, l-leucine, l-glutamine, 1-methylhistide), as well as amino acid metabolism pathways in chickens, were enhanced by MG supplementation. Gene expression analysis exhibited that dietary MGs could improve muscle protein synthesis and cell growth via the mTOR/S6K1 pathway. Dietary MGs enhanced the cecal amino acid metabolism by selectively increasing the proportion of genera Lachnospiraceae_NK4A136_group and Bacteroides. Conclusively, the present study demonstrated that dietary MGs improved chicken amino acid composition via increasing both gut amino acid utilization and muscle amino acid deposition.

Egg yolks contain abundant lipids, proteins, and minerals that provide not only essential nutrients for embryonic development but also cheap sources of nutrients for consumers worldwide. Previous composition analyses of egg yolks primarily focused on nutrients such as lipids and minerals. However, few studies have reported the effects of domestication and heating on yolk composition and characteristics. The objective of this study was to investigate the impact of domestication and boiling on the metabolite contents of egg yolks via untargeted metabolomics using GC-MS and LC-MS. In this study, eggs were collected from Fenghua teals, captive mallards, and Shaoxing ducks. Twelve duck eggs (half raw and half cooked) were randomly selected from each variety, and the egg yolks were separated for metabolic profiling. The analysis identified 1205 compounds in the egg yolks. Domestication generated more differential metabolites than boiling, which indicated that the changes in the metabolome of duck egg yolk caused by domestication were greater than those caused by boiling. In a comparative analysis of domestic and mallard ducks, 48 overlapping differential metabolites were discovered. Among them, nine metabolites were upregulated in domesticated ducks, including monoolein, emodin, daidzein, genistein, and glycitein, which may be involved in lipid metabolism; some of them may also act as phytoestrogens (flavonoids). Another 39 metabolites, including imethylethanolamine, harmalan, mannitol, nornicotine, linoleic acid, diphenylamine, proline betaine, alloxanthin, and resolvin d1, were downregulated by domestication and were linked to immunity, anti-inflammatory, antibacterial, and antioxidant properties. Furthermore, four overlapping differential metabolites that included amino acids and dipeptides were discovered in paired comparisons of the raw and boiled samples. Our findings provided new insights into the molecular response of duck domestication and supported the use of metabolomics to examine the impact of boiling on the composition of egg yolks.

Oxylipins are tightly linked to ovarian function. However, the roles and mechanisms of oxylipins in ovarian aging of laying ducks remain poorly understood. In this study, 72-week-old laying Jinyun ducks were categorized into high-laying (HL) and low-laying (LL) groups. Plasma and ovarian tissues were analyzed for antioxidant indices, transcriptomic, and targeted lipidomic. Results demonstrated that, compared to the LL group, the HL group ducks exhibited lower levels of MDA in both plasma and ovarian tissues, while exhibiting higher levels of SOD, GSH-Px, and T-AOC. Differentially expressed genes were primarily enriched in fatty acid oxidation and inflammation-related pathways, with FOXM1 identified as a pivotal gene involved in delaying ovarian aging. Furthermore, oxylipin profiles in plasma and ovary exhibit marked distinctions between the HL and LL group ducks. Notably, 5-hydroxy-eicosapentaenoic acid (5-HEPE) was substantially upregulated in both plasma and ovaries of the HL group ducks. Meanwhile, 5-HEPE significantly enhanced FOXM1 expression and mitigated oxidative stress in granulosa cells. Collectively, this study provides the first comprehensive analysis of oxylipin changes in the ovaries and plasma of ducks with differing laying performances at the late-laying stage. These findings offer novel insights into the prevention and alleviation of ovarian oxidative stress in ducks during this period.

Growth and egg production are the two most economically important traits in goose production systems. However, negative genetic correlations between these traits make it difficult to achieve balanced genetic improvement through selection. In this study, we analyzed whole-genome resequencing data from 1033 Zhedong White Geese to identify genetic variants related to birth weight (BW), body weight at 90 days (BW90), and egg number at 66 weeks of age (EN66). Single-trait genome-wide association studies (GWASs) identified 6, 5, and 5 lead SNPs significantly associated with BW, BW90, and EN66, respectively. By integrating network analysis, PLACO, and multivariate linear mixed models (mvLMMs), we further identified KCNAB2 and KCND3 as potential pleiotropic candidate genes influencing both growth and egg production. Notably, the variant at CHR25: 6006715, located within an intronic region of KCND3, was associated with increased BW (ZscoreBW = 4.44) and decreased EN66 (ZscoreEN66 = −3.55), showing strong pleiotropic significance (P_PLACO = 4.88 × 10⁻⁸). Collectively, these findings provide new insights into the genetic architecture underlying the antagonistic relationship between growth and egg production in geese and offer valuable genetic targets for developing breeding strategies that jointly optimize growth performance and reproductive efficiency.

Computer-assisted sperm analysis was conducted to phenotypically and genetically assess the sperm motility traits of Jinding drakes. The phenotypic evaluation revealed moderate variability across motility parameters, consistent with a polygenic inheritance pattern. Correlation analysis further demonstrated strong associations among velocity-related traits and inverse relationships between linearity and lateral head displacement metrics. Genome-wide association studies identified 15 significant single-nucleotide polymorphisms (SNPs) associated with five key sperm motility traits (straight-line velocity, curvilinear velocity, average path velocity, amplitude of lateral head displacement, and mean angular displacement) at a genome-wide threshold of p < 1 × 10⁻⁶. Notably, of these 15 SNPs, nine were concentrated on chromosome 1, indicating the presence of a genomic hotspot for regulation of sperm motility. Pleiotropic effects were evident, as several SNPs were found to influence multiple motility traits. Candidate genes implicated in essential sperm functions included Myo16 (cytoskeletal dynamics), Cep76 (flagellar structure), and Jarid2 (epigenetic regulation during spermatogenesis), as well as genes involved in membrane integrity, mitochondrial function, and immune regulation. These findings provide novel insights into the genetic architecture underlying sperm motility of Jinding drakes and establish a basis for molecular breeding strategies to enhance reproductive efficiency of waterfowl.