What am I missing about Genetics?

I'll see if I can help... Note: I am not an expert on meat birds, nor have I raised my own. This is what I understood from my readings.

First and foremost, what you need to realize with poultry, is that each breed has a Standard to which it has to be bred (i.e. The Standard of Perfection). Each breed has different qualities that it must adhere to that would characterize the perfect specimen of that breed, everything from eye/leg color to a maximum weight. Some breeds are required to lay certain colors of eggs, such as the Ameraucana, but there is no requirement for the number of eggs laid per year. However, commercial operations want high production birds as opposed to exhibition ones. Eggs aren't only used for eating. There's baking, cooking, etc. Think of how many eggs we use for cooking certain meals, especially in popular restaurants or fast food places.

To answer your question in bold: Yes, it is an unachievable goal. A pullet starts laying between 21-25 weeks old. Rarely do they start laying around 16 weeks, and those are the high production, small bodied mediterranean breeds like the Leghorn. Cornish (not Cornish crosses) spend their time and energy building the muscle we so desire, as opposed to the smaller Leghorn that doesn't need to grow muscle, thus it matures earlier.

Regarding the cross breeding. F1 crosses are the best there can be, whether it's layers or meat birds. Those F1 crosses have the best characteristics of their parentage: Layers have a high egg production rate and the Cornish X are bigger, meatier birds. Taking those F1 crosses and breeding them with other F1 birds of the same crossing (not necessarily related birds, but same breed parentage) doesn't maintain that vigor. Not to mention Cornish X can be difficult to breed due to limiting feed intake and heart problems. It's simply easier to make F1 crosses rather than continuing to use those birds to get the desired characteristics.

Hope this was able to help some.

 

Quote:It all has to do with money. It is not economical to feed an 8 pound chicken to lay a few eggs. That is why if you want to produce eggs and it be less expensive you raise some white leghorns. If you want some meat, you raise some cornish cross to about two months or so and you kill them and put them in the freezer.

If I want to drive a nail I use a hammer and if I want to saw a board I use a saw. Cornish cross and egg layers are like tools- you use them for the right purpose.

People cull birds because they do not meet the standard or have some kind of a flaw. People that cull birds are culling for show purposes and not utility.

No one cares if a female white leghorn only has one leg as long as it will produce 300 eggs per year it is fine.

The Standard of Perfection is difficult to meet- that is why it is called a standard of perfection. People who raise birds for show have to raise a bunch of birds and keep the ones that are closest to the standard.

Talking meat vs egg production is like talking meat verses milk production. It is the same thing with cattle- milk breeds produce milk more efficiently and beef breeds produce meat efficiently.

If you want lots of milk you use a holstein and if you want top dollar for your beef in the ring you raise black cattle or reds or what ever is selling the best.

My brother liked angus (male) X holstein (female) crosses. I do not know why. Maybe because the calves were larger. I am not into cattle but I think I make sense.

Tim

 

To echo what others have said, its about the hybrid vigor. The parent stock for the cornish crosses lay tons of eggs but the rate they grow is so much unless under the right conditions that the crosses rarely make it to laying age. With the average sexlink layer birds, even ones made at home tend to lay better than the parent breeds, even if its only a few eggs more. Looking back at old poultry books it is always so strange to see them mention 'good layers' that only lay 80 eggs a year. The selective breeding has done wonders in the last hundred years for the poultry market. I know some folks like to cross their cornish cocks on leghorn type hens for home meat birds. The leghorn type hens lay tons and tons of eggs and the cornish cock adds size. You get tons of chicks because the hens lay so many eggs, they might not grow as fast and as large as commercial birds but they do the job. When we bred goats we bred a boer buck to our lamancha and nubian does. We still got the milk from the does and the kids would still get to a fair size like the sire, plus the doe kids could be bred back to a dairy buck and produce a good amount of milk.
With cattle there is hybrid vigor with a common cross that comes to mind-the black baldy. It is a cross of an angusxhereford which are two good pure breeds but the cross tends to gain better and grow faster than the parent breeds in my experience.

I dont know if any of that helped but thought I'd post

 

Sure, that middle ground, exists, But doing both isn't possible, of course, because the very traits that make an ISA or Leghorn a great layer work against it being anything much more than skin and bones. The factors that make a CX convert feed into massive growth so quickly means it will never be a layer and frankly, won't even survive, in many case, and must be butchered. The chicken of olden days has crossed a great divide and n'er the twain shall meet. There has been a great fork in the road.

The true dual purpose breeds do exist and can be improved, but they'll never have the massive dollar support of the industry. Never. Yet, homesteaders and backyarders continue to enjoy and perhaps even improve the dual purpose birds. The Delaware, (though rare as hens teeth) and the White Rock, just to name a couple, come to mind. They can do it all, but won't do either one as well as a specialized "tool" (the metaphor used above, and a GOOD one). To be the Olympic champion of layers, you are never gonna win the gold at being a meat bird, and vice versa.