12/03/2025
Everything You Should Know About Jumbo Coturnix Quail... Bryant’s Roost post a few days ago sparked a lot of questions and conversations lately about Jumbo Coturnix quail, so I wanted to jump on the train about what “jumbo” actually means, how it is achieved, and what to look for if you are trying to improve or maintain size in your own line.
The term “jumbo” gets thrown around a lot, but not every large bird is a true jumbo, and not every heavy line will stay that way without good selection. Here is what really matters.
1. Jumbos are not made in one generation
A true jumbo line is developed over multiple generations of selecting for size, growth rate, and consistency. Throwing two big birds together one time does not build a jumbo program. The size has to breed true *consistently*. The heritability of growth is about 0.50- 0.60... Your selection makes a big difference but is not the end-all, be-all.
If you hatch a group and only a handful of birds finish large while the rest are average, you are looking at a mixed line, not a true jumbo.
2. Weight matters more than “looking big”
A bird can look tall or fluffy and still weigh very little. Good jumbo breeders use actual weight, not appearance. Mature jumbo hens should consistently finish out at 14 ounces or higher. Cockbirds will be slightly smaller (the opposite of chickens). There should be plenty of meat around the keel and breastbone on any jumbo bird, regardless of how they are feathered.
3. Growth rate is part of the equation
Jumbos should reach processing size quickly, but that's not a given. You should be weighing your birds at 10 weeks, not just when they feather out or start to lay. Size is one of the biggest advantages of true jumbo lines but it is not the *only* thing to think about. Efficiency and speed play just as much of a role as well.
Growth curves tell you far more about your line than a single final weight.
4. Type and structure still matter
A large bird that is narrow, weak-legged, or poorly built is not an improvement. The best jumbo lines have solid bone structure, good width through the body, and strong legs without lesions that can support the weight comfortably. Size without structure becomes a problem quickly.
A heavy bird should still move easily and carry itself well.
5. Start with the best stock you can
If you want to build a jumbo line, start with a breeder like Bryant’s Roost, who weigh their birds consistently across generations. Ask for numbers, not guesses. Ask what their hens and roosters typically finish at. Ask how long it takes them to reach processing size. A good breeder will have those answers and will be willing to answer it.
“Jumbo” should be backed by records, not opinions.
6. Keep your own weights and notes
Whether you are improving a line or maintaining one, record keeping is what separates real progress from accidental results. Weigh birds at four weeks, six weeks, and maturity. Track growth patterns. Compare males and females separately. Keep notes on fertility and hatch rate.
The strongest jumbo lines are built by people who track everything. That's why I built Poultry Pro, and why so many farms use it. Even pencil and paper is better than nothing though. It's not just another marketing term, it has weight and meaning behind the word.