What are the reasons for the slow rise in laying rate of laying hens

Under proper feeding and management conditions, good replacement pullets can reach a laying rate of 50% at 23 weeks of age, rise above 80% after 2-3 weeks, and exceed 90% at 27-28 weeks of age, rising very quickly. In actual production, it is common to see many flocks with delayed age at first egg, and after starting to lay, the laying rate rises slowly, only reaching 80% at 27-28 weeks of age, and afterwards the highest peak is less than 90%. The main reasons are:

1. Poor rearing of replacement pullets, hindered growth and development, especially failure to reach the breed standard body weight after 12 weeks of age, and poor body weight uniformity of the flock.

2. After being moved into the laying hen house, the feed was not replaced in time, or when the laying rate reached 5%, pre-lay feed was still being used instead of timely switching to peak-period feed.

3. Poor feed quality, such as too much content of miscellaneous meals like cottonseed meal and rapeseed meal; adulteration of feed ingredients, especially protein ingredients such as fish meal, soybean meal, and amino acids; unreasonable feed formula, insufficient limiting amino acids or improper amino acid ratios; low vitamin potency or even failure, etc.

4. Poor climate for laying hens starting to lay in summer, hot weather, and insufficient feed intake of the chickens.

5. The chickens had diseases during the brooding period or growing period, especially infectious bronchitis.

6. The flock is in a sub-healthy state or disturbed by atypical Newcastle disease. Wang Baihui