The Jumbo Cornish Cross Chickens are a cross between Cornish and White Rock Chickens. The development of the Jumbo Cornish came when the broiler industry started booming in the 1950s. The Jumbo Cornish was a very desirable meat breed because of it being more attractive as a dressed bird and because of its exceptional growth time. Males can reach 4.5 pounds in 6 weeks and almost 10 pounds in just 11 weeks!
The feed conversion rate of a Jumbo Cornish Cross is more than exceptional. It takes on average just two pounds of feed for every one pound of live broiler meat. Hens are sometimes used as layers but they aren’t the most efficient in that department. Females can be broody sometimes and are protective mothers. Depending on how you feed them, the Jumbo Cornish Cross can really live up to its “jumbo” name. Hens can weigh more than 12 pounds with males topping out around 15 pounds.
These birds have very large feet and legs. Most birds will have solid white plumage though some will carry some black specks. Beware of these birds because overfeeding them can lead them to become fat, lazy, and lethargic. Due to the Jumbo Cornish’s extremely fast growth, its legs will not be able to effectively support its body after they reach a certain weight. Keeping the bird healthy enough to fully mature and the breed is very difficult and not necessarily recommended.