Layer’s 18-25 weeks is called climbing period. At this stage, egg weight, egg production rate, and body weight are all rising rapidly, and the requirements for nutrition are very high, but the increase in feed intake is not much, which requires to design nutrition for this stage separately.

A. Several characteristics of 18-25-week-old layer: (Take Hyline Grey as an example)

1. The egg production rate has increased from 18 weeks to more than 92% at 25 weeks of age, increasing the egg production rate by about 90%, and the number of eggs produced is also close to about 40.

2. Egg weight has increased by 14 grams from 45 grams to 59 grams.

3. The weight is increased by 0.31 kg from 1.50 kg to 1.81 kg.

4. Lighting increased Lighting time increased by 6 hours from 10 hours to 16 hours.

5. The average feed intake increased by 24 grams from 81 grams at 18 weeks of age to 105 grams at 25 weeks of age.

6. Young hens have to face various stresses of starting production;

At this stage, it is not realistic to rely on the chicken body to adjust itself to meet the nutritional needs. It is necessary to improve the nutrition of the feed. The low nutrient concentration of the feed and the inability to increase the feed intake quickly will cause the nutrition to fail to keep up with the body’s needs, resulting in The chicken group has insufficient energy reserves and stunted growth, which affects the performance of production.

B. The harm of insufficient nutritional intake

1. The harm of insufficient energy and amino acid intake

The feed intake of layer increases slowly from 18 to 25 weeks, resulting in insufficient energy and amino acids to meet the needs. It is easy to have a low or no peak of egg production, premature aging after the peak, small egg weight, and egg production duration. Shorter, lower body weight and less resistant to disease.

2. The harm of insufficient calcium and phosphorus intake

Insufficient intake of calcium and phosphorus is prone to keel bending, cartilage, and even paralysis, fatigue syndrome of layer, and poor eggshell quality in the later stage.