Application and Effects of Feed-Grade Shell Powder in Poultry Layer Feed
Feed-grade shell powder is made from natural shells through processes such as cleaning, crushing, and sterilization. Its core component is calcium carbonate (content usually ≥95%), and it also contains minerals like phosphorus, magnesium, and zinc. It serves as a high-quality calcium supplement in poultry layer feed, with the following application methods and effects:
I. Main Application Methods
1. Direct Addition to Basic Feed
As a calcium supplement, it is added according to the different growth stages of poultry layers:
- Chick stage: Added at a ratio of 1%-2% to meet the basic calcium demand for bone development.
- Laying hen stage: Added at a ratio of 3%-5% to focus on supporting calcium consumption for eggshell formation.
It is usually mixed evenly with basic feeds such as corn and soybean meal before feeding, requiring no additional complex processing.
2. Compound Matching with Other Nutrients
It can be matched with phosphorus sources (e.g., dicalcium phosphate) at a calcium-to-phosphorus ratio of approximately 2:1 (in line with the physiological needs of poultry layers), or added together with vitamin D (to promote calcium absorption). This avoids low absorption efficiency caused by single calcium supplementation, making it particularly suitable for laying hens in the peak laying period.
II. Core Application Effects
1. Improving Eggshell Quality and Reducing Breakage Rate
The main component of eggshells is calcium carbonate. Calcium provided by feed-grade shell powder directly participates in eggshell synthesis, which can:
- Increase eggshell thickness by 0.02-0.05mm.
- Enhance eggshell strength by 10%-15%.
- Reduce the egg breakage rate from 8%-12% to 3%-5%, minimizing egg loss during the breeding process.
2. Ensuring Laying Performance and Extending the Laying Cycle
Laying poultry need to intake 3-4g of calcium per day during the laying period. The slow-release calcium property of shell powder can continuously meet this demand, preventing a drop in laying rate due to calcium deficiency:
- Under normal conditions, the laying rate of hens fed with shell powder can be stably maintained above 85% (compared to less than 80% in the non-added group).
- The peak laying period can be extended by 1-2 months.
3. Promoting Bone Development and Reducing Disease Risks
- Chick stage: Supplementing with shell powder can prevent "weak leg disease" and "rickets" caused by calcium deficiency.
- Adult poultry stage: It can prevent osteoporosis caused by calcium loss, reduce the phenomenon of paralyzed chickens in the late laying period, and lower the breeding mortality rate (usually reducing the mortality rate of poultry layers from 5%-7% to below 3%).
4. Improving Egg Nutrition and Flavor
Natural minerals (e.g., magnesium, zinc) in shell powder can be transferred to eggs in small amounts:
- Increase calcium content in egg yolks by 5%-8%.
- Reduce the fishy odor of eggs (minimizing metabolic odors caused by nutritional imbalance), enhancing the market acceptance of eggs.
III. Application Advantages (Compared with Other Calcium Sources)
Compared with limestone powder (a commonly used calcium source), feed-grade shell powder has the following advantages:
- Higher calcium content: Limestone powder contains about 90% calcium carbonate, while shell powder contains ≥95%.
- Finer particles and better palatability: Increases the feed intake of poultry layers by 3%-5%.
- No heavy metal residue risk: After compliant processing, the content of harmful substances such as lead and arsenic in natural shells is ≤0.1mg/kg, meeting feed safety standards, making it more suitable for long-term feeding of poultry layers