Coturnix quail are very easy to selectively breed to what you want, because their life cycles are so quick. They hatch in just a little over 17 days and many of mine lay by 6 weeks and 2 days after hatching. When I kept track of it, the earliest I have had any lay was 5 weeks and 5 days. Pullet eggs are smaller than normal, but usually hatch fairly well.
There are some people who very carefully select their breeders for specific purposes, but most people just breed whatever they have. Few people understand the need to or have the heart to cull. Most animals bred in captivity, should never be used as breeders. Only the best should be bred.
I like colors. With the modifiers and patterning genes there are probably more than 60 colors in Coturnix now. I think I have all of the colors Coturnix come in or at least the ability to produce them.
If you don't select for size, Coturnix get smaller and lay smaller eggs over the generations. They become more like white leghorns, having smaller body size, except that you lose egg size too. There's a definite tradeoff between quail size and laying capability. Bigger quail lay poorly. There is also a tradeoff between egg size and number of eggs laid during the lifetime of the hen. Hens that lay huge eggs die young and rarely lay daily. The most common cause of death for hens in their prime is prolapsing when laying.
I keep 3.5 hens per rooster in colonies consisting of 20 roosters and 90 hens. I cull birds very frequently. I have buyers that purchase all of my culls. I do the first culll at around 10 weeks. All unhealthy, damaged or deformed, adult quail are culled. All quail that are not breeding are culled. Roosters are culled first for size and then color. Hens are culled for size, but less harshly. Around 16 weeks I cull again. If I ever see a quail eating an egg, it's instantly culled. Badly injured quail are instantly culled. Full adult quail that are flighty or wild acting are culled.
Keith
