Background: Choline is an important nutrient, playing key roles in numerous metabolic pathways relevant to animal health.Objectives: The objective of this study was to evaluate the effect of dietary choline on the lipid parameters, cardiovascular health (CVH), and levels of egg trimethylamine (TMA) and cholesterol in breeder ducks during the late laying period.Methods: A total of 60 Jingjiang ducks were randomly separated into six replicates of 10 ducks each. After peak production until 65 weeks of age, the birds were fed a control basal diet. The same ducks served as the control group until 65 weeks of age, when the same ducks served as the choline‐supplemented group, after 15 days of dietary choline supplementation at 2955 mg/kg choline above and over the basal diet initially provided. The 15 days of choline supplementation included an initial 5‐day acclimatisation period.Results: Dietary choline supplementation increased serum TMA (p < 0.01), high‐density lipoprotein cholesterol, very low‐density lipoprotein, and triglyceride levels in older breeder ducks. However, it did not change the levels of trimethylamine N‐oxide but decreased the atherosclerosis index compared with those of the control group (p < 0.01). Moreover, it increased (p < 0.01) the egg yolk TMA levels but did not change the concentrations of cholesterol in egg yolk.Conclusions: Dietary choline supplementation had a beneficial effect on lipid parameters and CVH in older breeder ducks, although it increased the serum and egg yolk TMA levels.

Microbial contamination of hatching eggs often leads to reduced hatchability and poor chick quality. As trimethylamine (TMA), a metabolite derived from dietary choline, has antimicrobial properties, increasing yolk TMA contents may increase bacterial resistance to eggs; however, the effects of TMA concentrations on chick quality remain unknown. Hence, this study was conducted to determine the effects of yolk TMA concentrations on the hatchability and chick quality of dwarf hens with different FMO3 genotypes. Hens (n = 140) were divided into control and experimental groups; the latter received choline chloride (2800 mg/kg) to elevate their yolk TMA concentrations. The TMA content, Pasgar score, hatchability, and post-hatching performance were evaluated. The results showed that choline supplementation significantly increased TMA concentrations in hens with AT and TT genotypes. Higher yolk TMA concentrations (≥4 µg/g) correlated with improved Pasgar scores and reduced abnormalities in vitality, navel, and yolk sac absorption. Hatchability peaked at 6.49 µg/g TMA, suggesting a threshold effect. Although the growth rate remained unaffected, chick mortality decreased in the high-TMA group. Therefore, moderate TMA concentrations can enhance egg antimicrobial defenses and improve reproductive performance. This strategy provides a biologically grounded alternative to traditional chemical disinfection in hatcheries.

Egg quality during storage is a critical factor influencing consumer acceptance and food safety. However, the effects of storage methods on eggshell translucency and surface microbiota remain insufficiently understood. In this study, three common packaging methods, paper pulp trays (PPT), expanded polyethylene foam trays (EPE), and transparent plastic boxes (TPB), were evaluated to assess their impact on egg translucency, internal quality, and microbial communities. Egg quality traits were measured, and microstructural and elemental characteristics were examined using scanning electron microscopy and compositional analysis. In addition, 16S rRNA sequencing was performed to characterize the eggshell surface microbiota. The packaging method significantly influenced translucency development, with EPE mitigating mottling better than PPT and TPB. Storage duration was the predominant driver of internal quality deterioration, particularly affecting the albumen height and Haugh units. Translucency was not associated with shell thickness or mineral content but was likely associated with moisture dynamics. Distinct microbial communities are shaped by different packaging materials. These findings provide new insights into the mechanisms underlying translucency and microbial ecology during egg storage. This highlights the practical implications of optimizing packaging strategies to maintain egg quality, extend the shelf life, and ensure microbial safety.

Egg hatchability is a key indicator of reproductive efficiency in poultry. Egg quality, which serves as the material basis for embryonic development, plays a pivotal role during incubation. Egg quality includes both external and internal components that influence embryonic growth and hatchability through the modulation of gas exchange, water balance, microbial barriers, and nutrient supply. External qualities, including eggshell thickness, strength, and pore structure, determine protective properties and permeability, whereas eggshell color and translucency reflect the structural integrity and mineralization status. Internal quality, including the yolk-to-albumen ratio, albumen freshness (Haugh unit, HU), and albumen physicochemical properties, affects the nutrient supply and stability of the internal environment of the egg. The effects of egg quality components are further modulated by management factors such as storage duration, storage temperature, and incubation conditions. This review summarizes the mechanisms linking egg quality to hatchability and outlines strategies for improving egg quality and hatchability.