Using intense selective breeding, poultry companies have created modern meat-type chicken strains that are vastly different from heritage breeds of poultry, such as their Plymouth Rock and Cornish breed ancestors. Modern broilers grow three times faster than old-fashioned breeds of chickens, and they need to eat only half of the feed to reach the same weight.Explosive growth and super feed efficiency come at a price, however. Broilers grow too fast for their own good. Bones, joints, and internal organs barely (or can’t) keep up with the rapid growth. The result could be a variety of problems, including the following.
Ascites: A broiler’s heart may fail trying to pump blood to a rapidly growing body. The failing heart enlarges, and straw-colored fluid fills up the abdomen and lungs; this fluid build-up is called ascites. Birds with ascites may pant, even in cool weather, and their combs may have a bluish tinge.
To lower the incidence of ascites, make sure your housing for broilers is well-ventilated. Dust and high ammonia levels increase cases of ascites in broiler flocks.
Leg problems: Broilers can grow at a faster rate than their immature skeletal systems can support, leading to painful twisting or bowing of the legs or spine. Birds that are unwilling to get around because of leg pain or are unable to move well due to leg and back deformities may die of starvation, thirst, or trampling by flock mates.
Sudden death syndrome: Healthy-looking broilers can flip over and die suddenly, expiring on their backs with a brief flurry of wing-flapping. You may think you’ve witnessed a fatal chicken heart attack. This event, known as sudden death syndrome, or flip-over disease, is most commonly seen in broiler chickens between 2 and 4 weeks of age. Scientists don’t understand the exact cause.
With a functional backyard lifespan of just a few months, broilers make terrible pet chickens. Broiler growers should be prepared to perform humane euthanasia for broken-down broilers.
Slowing that breakneck pace of growth, just a little, especially during the first three weeks of the growing period, can reduce the chances of ascites, leg problems, or sudden death syndrome in a batch of broilers. Feed restriction is the main method that you can use to slow growth. Here are two simple options for a broiler feed-restriction program:
Option 1: Feed meals twice a day, rather than offering feed free-choice. Give the birds enough food so that they consume it all within three hours. No snacking between meals.
Option 2: When the broilers are a week old, remove all feed from the pen every evening and put it back in the morning, 12 hours later. Do this every day until the birds are ready to be processed.