by: Dr. Mohammed Al-Zouqari - Yemen

This critical phase is very important in the life of laying hens. If not managed properly, it can negatively affect overall health and future egg production. As commercial chickens grow from chicks to hens, their nutritional requirements change. The critical phase in this development is the transition from grower feed to layer feed, which usually occurs between the sixteenth and twentieth week of age, though this period may vary depending on the commercial strain. If this transitional period is not managed correctly, it will adversely affect health and egg production.

This article reviews the nutritional needs of commercial chickens during this critical phase and provides recommendations to ensure a smooth, gradual transition without negatively impacting flock performance.

Concept and Idea of Transition

The transition from starter feed (pre-production feed) to layer feed typically occurs when the chickens are between 16 and 20 weeks of age, just before they start laying eggs or, for some, when egg production exceeds 2% or 5%. Throughout the growth phase, feed formulations are carefully designed to support growth and development. However, when the hen reaches the point of egg laying, her nutritional needs shift to support egg production, requiring a different balance of nutrients. These nutritional needs during the transition period include:

• Protein
  Protein is a crucial component in the diet of laying hens during the transition phase. Laying hens require a gradual increase in protein levels, with pre-layer feed generally containing a higher protein percentage to promote growth, while layer feed contains less protein but more calcium. A gradual transition is essential to prevent stress and malnutrition.

• Calcium
  Calcium is essential for forming strong egg shells. As hens prepare to lay eggs, their bodies need more calcium for shell formation. Typically, layer feed has higher calcium content compared to pre-production feed. A sudden increase in calcium can lead to kidney problems, so the transition should be gradual. Pre-production feed usually contains around 2% calcium, while during full egg production, calcium levels often reach or exceed 4%.

• Energy
  As hens begin laying eggs, they need more energy. Layer feed typically has higher energy levels compared to starter feed, mainly due to the additional calories required for egg production and the restrictive feeding systems used with some hybrid strains. Ensuring appropriate energy levels is crucial to support the increased metabolic demands.

• Phosphorus
  Maintaining the correct balance between calcium and phosphorus is critical for healthy egg shell formation. Commercial laying hens should have access to feed with a balanced and appropriate ratio of calcium to phosphorus to prevent deficiencies. Excess phosphorus can reduce calcium absorption from the digestive tract. Proper management of nutrition during this transitional period is essential to support healthy egg production and overall bird welfare.

Recommended Guidelines for a Smooth Transition

• Gradual Changes
  To ensure a smooth transition from pre-production to layer feed, gradual changes in the diet are essential. Over about a week, mix pre-production feed with layer feed, gradually increasing the latter. This allows the birds' digestive systems to adjust to the new diet without causing stress.

• Monitor Body Condition
  Regularly monitor the body condition of laying hens. Adjust the transition based on weight and the overall health of the flock. If the hens are losing or gaining too much weight, it may indicate an issue with the energy concentration or allowable feed.

• Water Quality
  Ensure access to clean, fresh water at all times. Laying hens will need more water during the transition to layer feed, especially to metabolize the increased mineral content.

• Vitamin and Mineral Supplements
  Consult a poultry nutrition specialist to determine the necessary vitamin and mineral supplements during the transition. Appropriate supplements can ensure the hens receive all essential nutrients. Note that some micronutrients can be stored for long periods, while others need to be provided daily.

• Environmental Factors
  Ensure that the housing environment is optimal. Stress factors such as overcrowding, temperature fluctuations, or disease outbreaks can impact the transition process. Minimizing stress through proper nutrition, including antioxidants, can help.

Practical Example

Below is a practical example used in one commercial farm. There is no guarantee that this program will work elsewhere, so it is provided here as a reference only.

• Pre-Layer Feed (per 100 kg):
  • Corn, sorghum, wheat: 50-60 kg
  • Soybean or canola meal: 20-25 kg
  • Energy, protein, and fiber supplements: 10-15 kg
  • Fine calcium carbonate: 2-4 kg
  • Coarse limestone, shellfish shells: 1-3 kg
  • Dicalcium or monocalcium phosphate: 1-3 kg
  • Soy or canola oil: 2 kg
  • Salt: 0.3 kg (adding a small amount of sodium bicarbonate is also advisable)
  • Amino acids: as needed
  • Vitamin and mineral premix: follow your nutritionist’s recommendations
  • Additives: follow your nutritionist’s recommendations

Nutritionists will follow either hybrid strain guidelines or their specifications based on experience and/or what they deem appropriate.

Guidelines for Transition

Start the transition when the chickens are around 18 weeks old or just before they begin laying eggs. Over one week (or two weeks in some cases), gradually replace pre-layer feed with layer feed, following this general guidance:

1. Days 1 to 2: Feed 75% pre-layer feed and 25% layer feed.
2. Days 3 to 4: Feed 50% pre-layer feed and 50% layer feed.
3. Days 5 to 6: Feed 25% pre-layer feed and 75% layer feed.
4. Day 7: Feed 100% layer feed.

Transitioning from pre-layer to layer feed is a crucial phase in the life of commercial laying hens. Proper nutritional management during this transitional period is essential to support healthy egg production and overall bird welfare. By gradually adjusting the diet, monitoring condition, and ensuring an optimal environment, poultry farmers can help laying hens smoothly transition into egg production, ultimately leading to improved productivity and healthier flocks.

Reference: Ioannis Mavromichalis. 2024. Feed strategy. 18-21