How long does it take to produce fertile eggs?
If the rooster in a flock dies, or is removed, the hens will continue to produce fertile eggs for up to 4 weeks, depending on bird species. The period of time that fertile eggs can be produced without additional matings can carry on to several weeks. If a rooster is separated from the hens and replaced by another, it may require 3 weeks before it can be guaranteed that all eggs will produce chicks sired by the new rooster. The number of chicks sired by the new rooster will increase during this period, but some chicks sired by the old rooster could hatch. Birds like waterfowl and game birds have longer periods during which fertile eggs can be produced without matings.
