American Association of Colleges of Nursing (AACN) - The Clinical Nurse Leader; American Association of Colleges of Nursing's White Paper on the Education and the Role of the Clinical Nurse Leader; American Association of Managed Care Nurses; American Board of Managed Care Nursing; AONE Institute for Leadership Research & Education
1 Female fleas cannot lay eggs until after their first blood meal and begin to lay eggs within 36-48 hours after that meal. 2  The female flea can lay 2,000 eggs in her lifetime.  The female flea consumes 15 times her own body weight in blood daily.
Factor #1 - Breed. Chicken breeds that are generally considered to be layers tend to lay sooner than those considered meat or dual purpose breeds. The hybrid laying breeds start laying as early as 16 weeks. Heritage laying breeds tend to lay about 4 weeks later (20 weeks) and all other breeds will begin laying between 20-32 weeks of age. I have no hard evidence to prove this, but I suspect that the breeds that lay the most eggs each year are also ones that are likely to lay the soonest.