The Application of Choline Chloride in Layer Production: A Comprehensive Analysis
The Impact of Dietary Supplementation with Choline Chloride and DMPT on Feed Ingestion and Protein Utilization in Fish
September 8, 2025
Abstract
Choline chloride, a vitamin-like essential nutrient, plays a crucial role in modern intensive layer production. Far from being a simple feed additive, it is a key substance involved in fat metabolism, nerve conduction, and cell membrane integrity. This article explores the application value of choline chloride in layer production, detailing its mechanisms of action, including prevention of fatty liver syndrome, methionine sparing, promotion of lipid transport, and enhancement of nervous system function. By synthesizing domestic and international research findings, this paper systematically analyzes the specific effects of choline chloride on egg production rate, egg weight, egg quality, feed conversion rate, and liver health, and provides recommended dosages based on different production stages. The comparison table clearly shows the significant differences in key performance indicators between groups supplemented with choline chloride and control groups, providing theoretical basis and practical guidance for scientific formulation and precision nutrition in layer farming.
1. Introduction
The core goal of the layer industry is to maintain the length of peak production, increase total egg production, ensure egg quality, while minimizing feeding costs. The key to achieving this goal lies in precise nutritional regulation. Among numerous nutritional additives, choline chloride has become an indispensable component in layer diets due to its unique and irreplaceable physiological functions.
Although classified as a B vitamin, poultry’s requirement for choline is much higher than for other vitamins. More importantly, the endogenous synthesis of choline in the liver of laying hens often cannot meet the huge metabolic demands of their high-production state, especially in modern diets with low fish meal and high plant-based ingredients. Therefore, exogenous supplementation of choline chloride is particularly important. Choline deficiency will directly lead to fat metabolism disorders, decreased production performance and increased mortality. Thus, in-depth research on the application of choline chloride in layer production is of great significance for improving economic efficiency and animal welfare.
2. Physiological Functions and Mechanisms of Choline Chloride
The role of choline chloride in laying hens is multifaceted, and its main mechanisms can be summarized as follows:
2.1 Prevention of Fatty Liver Syndrome (FLS)
This is the core function of choline chloride. The liver of laying hens is the main site for the synthesis of yolk lipoprotein (very low-density lipoprotein, VLDL), which is responsible for transporting fat from the liver to the blood and ultimately depositing it into developing follicles to form yolk. Phosphatidylcholine (lecithin) is an essential component for VLDL synthesis, and choline is the precursor for phosphatidylcholine synthesis. When dietary choline is insufficient, VLDL synthesis is blocked, causing large amounts of fat to accumulate in the liver, forming fatty liver. Severe fatty liver is fragile and prone to rupture and bleeding, causing “fatty liver hemorrhagic syndrome (FLHS)”, which is the main cause of sudden death in laying hens.
2.2 Methionine Sparing Effect
Methionine is an essential amino acid and expensive. In the body, methionine can provide methyl groups for various reactions through transmethylation. After choline is oxidized to generate betaine, it can also serve as an efficient methyl donor. Sufficient available choline can replace methionine to provide methyl groups, thereby allowing more methionine to be used for body protein (including egg protein) synthesis, improving the utilization efficiency of methionine and reducing the addition cost of methionine in the diet.
2.3 Promotion of Lipid Transport and Utilization
As mentioned above, choline affects the efficiency of fat transport from the liver to the follicles by participating in the synthesis of VLDL. This is not only related to liver health but also directly determines the size of the yolk and egg weight. Efficient lipid transport ensures that energy is effectively utilized in the form of fat rather than abnormally deposited in the liver.
2.4 Maintenance of Nervous System Health
Choline is a precursor of the neurotransmitter acetylcholine. Acetylcholine is responsible for transmitting signals at neuromuscular junctions and in the brain, affecting muscle movement, memory and learning ability. Sufficient choline ensures normal nerve function and behavioral performance of laying hens.
2.5 Constituent of Cell Membrane Structure
As the main component of phosphatidylcholine, choline is a basic substance for maintaining the integrity and fluidity of all cell membrane structures, which is essential for maintaining normal cell function.
3. Specific Effects of Choline Chloride on Layer Performance
Numerous studies have confirmed that adding an appropriate amount of choline chloride to layer diets can bring significant production benefits.
3.1 Effects on Laying Rate and Egg Mass
Choline chloride provides the basis for sustained high and stable production by ensuring liver health and promoting the directional transport of nutrients. Flocks deficient in choline experience a more rapid decline in egg production rate and have difficulty maintaining peak production. Supplementing with sufficient choline can significantly improve the egg production rate in the middle and late stages of production (after 40 weeks of age).
3.2 Effects on Egg Weight
Yolk is the main factor determining egg weight. By promoting the synthesis of VLDL, choline directly improves the efficiency of the liver in transporting fat and fat-soluble vitamins to the ovaries, thereby increasing yolk weight and volume. Studies have shown that adding an appropriate amount of choline chloride during peak laying period can significantly increase average egg weight.
3.3 Effects on Feed Conversion Ratio (FCR)
By improving lipid metabolism and exerting a protein-sparing effect, choline chloride improves the utilization efficiency of energy and protein in feed. This means that the amount of feed consumed per unit weight of eggs produced is reduced, thereby lowering production costs.
3.4 Effects on Egg Quality
Yolk color: Fat-soluble pigments (such as lutein) need to rely on VLDL to be effectively deposited into the yolk. When choline is sufficient, yolk pigment deposition is more sufficient, and the yolk color is deeper and brighter, which is more popular with consumers.
Reduction of broken eggs: The lipid transport function of choline also affects the formation of the eggshell membrane and the deposition of calcium, indirectly helping to improve eggshell quality and reduce breakage rate.
3.5 Effects on Liver Health and Mortality
As mentioned earlier, supplementing with choline chloride is the most effective and economical nutritional means to prevent FLHS. Maintaining liver health can significantly reduce sudden death of laying hens caused by liver rupture, reduce mortality, and extend the laying cycle.
4. Application Recommendations and Dosage
Choline requirements are affected by many factors, including the breed of laying hen, laying stage, dietary energy level, amount of methionine and betaine added, and environmental temperature.
General recommended dosage: China’s “Chicken Feeding Standard” (NY/T 33-2004) recommends that the choline requirement for laying hens is 1050 mg/kg diet (equivalent to about 1250-1300 mg/kg of choline chloride, since choline chloride contains about 75-80% choline).
Adjustments in practical application:
- Early laying period to peak laying period (18-35 weeks of age): During this period, the egg production rate increases rapidly, egg weight continues to increase, and the liver load is greatest, which is the high incidence period of fatty liver. The recommended dosage can be increased to 1100-1300 mg/kg diet (calculated as choline), that is, supplement with pure choline chloride 500-800 mg/kg.
- Mid-laying period (36-50 weeks of age): Maintain liver health and support high production. Can be added according to the standard amount.
- Late laying period (after 50 weeks of age): The incidence of fatty liver is higher at this stage, and eggshell quality begins to decline. The addition amount can be increased again to 1200-1400 mg/kg (calculated as choline) to strengthen liver function and delay the decline in egg production rate.
Interaction with methionine and betaine: When the dietary methionine level is sufficient or betaine is added additionally, the amount of choline added can be appropriately reduced, but it cannot be completely omitted, because the structural function of choline (constituting cell membranes and VLDL) cannot be replaced.
5. Comprehensive Effect Parameter Comparison Table
The following table synthesizes the results of multiple experimental studies, comparing the performance differences between groups supplemented with sufficient choline chloride and choline-deficient control groups in typical layer diets.
| Performance Indicator | Control Group (Choline Deficient) | Treatment Group (Adequate Choline) | Change Magnitude | Main Reason |
|---|---|---|---|---|
| Laying Rate (%) | 80 – 84% | 86 – 90% | +4-6% | Liver health maintains high production, normal nervous system function |
| Average Egg Weight (g) | 58 – 60 | 60 – 62.5 | +2-2.5g | Promotes VLDL synthesis, increases yolk weight |
| Daily Feed Intake (g/bird/day) | 110 – 115 | 108 – 112 | Basically flat or slightly lower | – |
| Feed Conversion Ratio (FCR, kg feed/kg egg) | 2.15 – 2.25 | 2.05 – 2.10 | -4.7% ~ -6.7% | Improves fat and protein utilization efficiency |
| Broken Egg Rate (%) | 1.5 – 2.5% | 1.0 – 1.8% | -0.5% ~ -0.7% | Indirectly improves nutrient deposition and eggshell quality |
| Yolk Color (Roche scale) | 9 – 10 | 10 – 11 | +1 level | Promotes deposition of fat-soluble pigments into yolk |
| Hepatic Lipid Content (%) | 40 – 55% (High risk) | 30 – 35% (Normal) | -25% ~ -36% | Promotes fat transport, prevents fatty liver |
| Mortality from Liver Disease (%) | 3 – 8% | 1 – 2% | -60% ~ -75% | Effectively prevents fatty liver hemorrhagic syndrome |
6. Conclusion and Prospects
In summary, choline chloride is a key nutritional regulator for ensuring efficient and healthy production of modern laying hens. It is not simply “icing on the cake” but rather ” timely assistance” for maintaining normal body metabolism, especially liver lipid metabolism. By supplementing with sufficient choline chloride, we can effectively:
- Prevent nutritional metabolic diseases (FLS/FLHS) and significantly reduce mortality;
- Significantly improve egg production rate, egg weight and feed reward, and enhance economic benefits;
- Enhance yolk quality to meet market demands.
In the future, with the updating of layer breeds and changes in feeding models, research on the demand for choline chloride should be more refined, such as exploring the choline requirements of layers with different genetic backgrounds, and studying the best combination of choline with other metabolic regulators such as betaine and carnitine, so as to achieve precise nutrition and promote the development of the layer industry in a more efficient, healthier and more sustainable direction.
References: Available upon request. Based on synthesis of multiple poultry nutrition studies and feeding standard guidelines.
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CHOLINE CHLORIDE is a basic constituent of lecithin that is found in many plants and animal organs. It is important as a precursor of acetylcholine, as a methyl donor in various metabolic processes, and in lipid metabolism. PubChem CID: 6209 Chemical Names: CHOLINE CHLORIDE; 67-4... Molecular Formula: C5H14NO.Cl or C5H14Cl... Molecular Weight: 139.623 g/mol
