Mendel was not the first to propose genetics however, he was the first to figure out that genes (he called them elements) came in pairs and that one member of each pair came from each parent. As a result of his realization regarding pairs of genes, Mendel determined what are called Mendel's laws of inheritance..
Chickens usually don't simply stop laying eggs when they get to a certain age, but they will lay fewer as they get older.That said, most laying breeds will lay more or less productively in backyard terms for five or seven years.hickens usually don't simply stop laying eggs when they get to a certain age, but they will lay fewer as they get older.
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.