Dr. Mark raises free-range rabbits, poultry, horses, and sheep at his small farm. He is a veterinarian and also cares for dogs and cats.
Have you taken a good look at your flock lately? A lot of us do not slaughter our backyard birds, but even if you do not, you can palpate the keel and should feel meat but not a thick layer of fat. If you have noticed that your chickens are spending most of their time in the coop, laying fewer eggs, developing foot problems, and becoming eggbound, they may have gotten too fat.
Obesity in backyard chickens is on the rise for several reasons:
- Excessive feeding
- Fatty table scraps given in excess
- Artificial housing (excessive lighting)
- Genetics (Many chicken breeds are now selected to become heavier even faster, and some birds suffer from polyphagia, a hyperactive appetite that makes them want to eat anything set before them.)(1)
If you notice from your exam that your chickens are actually underweight, here are some tips on how to help them gain weight.
Some modern broiler breeds grow so heavy that they become lame. Do not let your backyard chickens become like this.
Problems Found in Obese Chickens
But is obesity in chickens really such a big issue or should we just accept that it is the way backyard pets are meant to be? Backyard chickens that become obese suffer from:
- heart attacks
- fatty liver disease (fatty liver hemorrhagic syndrome)
- fewer eggs produced
- egg binding
- large eggs that are hard to pass
- lowered fertility (2)
- prolapsed vent (maybe from the large eggs)
- swollen feet (bumblefoot or foot pad ulcers)
Average Weights for Most Common Backyard Chicken Breeds
All chickens can become obese, but those most likely to suffer are large birds with heavy appetites. The Sussex is one of those chickens with an unusual appetite, Cornish or Cornish crossbred and other meat-type breeds have been selected to eat all day even beyond their needs, and very calm birds like the Cochin can also become overweight more easily. ALL large breeds are more prone to obesity and need to be monitored closely.
Here are the normal weights of the most common backyard breeds:
- Rhode Island Red (6-9 pounds)
- Buff Orpington (7-10 pounds)
- Australorp (6-11 pounds)
- Barred Rock (7-10 pounds)
- Americauna (5-7 pounds)
- Leghorn (5-8 pounds)
- Wyandotte (6-10 pounds)
- Brahma (7-12 pounds)
- Speckled Sussex (6-10 pounds)
- Maran (6-10 pounds)
- Cochin (8-11 pounds)
- Araucana (4-5 pounds)
- Polish (4-7 pounds)
- Silkies (2-4 pounds)
The weights listed are just general guidelines. A Brahma is always larger than a SIlkie, but even if your Silkie weighs only 4 pounds and fits the scale above, she might be 100% overweight, like a 300-pound human. If your chickens are not on this list, do an internet search to find their correct weight but be sure to feel their keel and evaluate them carefully even if they have the "correct" weight.
Tips to Control Obesity in Backyard Chickens
Although less than 10% of backyard chickens have obesity-related problems as a cause of death, (3) overweight chickens are sick animals and are suffering from other obesity-related diseases and not living up to their potential.
Here is a list of tips that will help you when you realize you need to keep your chickens from becoming too fat:
Provide More Exercise
Lack of exercise is one of the biggest issues with backyard birds. In some regions, this is not even an issue as birds need to roam around to find insects and anything else to eat, but in backyard flocks, the food is set out each day right in the coop and the only reason a hen needs to move around is to find something different to eat.
Consider moving food away from the coop, giving any treats in another area, and even getting a rooster to keep the chickens on the move. (There are laws against roosters in some cities so be sure to check before going through with this.)
Exercise is great but alone it is not the answer, as humans have learned. Be sure to try these other tips.
Give a Balanced Low-Calorie Diet
Flax seed has also been clinically proven to reduce fatty liver, and even if you cannot find it in a mixed feed you can supplement feed your hens with this healthy fiber source. (4) Other fiber sources that you might find are wheat bran, sunflower seed meal, or pea hulls. High fiber low-calorie foods are often not available in feed store chicken mixes because keeping the excess weight off is not the aim of producers.
Even if you do not make up a feed based on lower calories and higher fiber, there are some commercial feeds that are better than others. Avoid whole corn, scratch-type feeds that are mostly high-fat grains, and diets that are sold for broiler types. I prefer to give my birds lower calorie foods when they are free-range and a limited amount of a commercial layer feed if they are in confinement.
Do Not Feed Free Choice
Chickens have to store their feed in the crop before it moves down into the stomach so they will tend to eat many small meals throughout the day. That does not mean they need to eat all of the time, especially since most of the feeds we are giving them provide for their needs in a small volume.
Measure out the amount you are going to give during the day, about one-half cup per bird, and give it several times per day as a meal.
Cut Out Table Scraps and Most Other Treats
Backyard laying hens are great pets since they not only provide us with the joy of interacting with them, but they also provide us with something for the table. Purina recommends that we not give our backyard flocks more than 10% treats in their diet and buy the other 90% from them.
A lot of backyard chicken raisers though take too much advantage of their hens' proclivity to eat anything and just give their chickens whatever they have left from the table. There are certain things chickens cannot or should not eat. If your family eats vegetables and salads, by all means, give the chickens your leftover lettuce, kale, broccoli, etc.
If you are eating a lot of fried foods and takeout from KFC and other fast food places, refrain from giving your chickens those cold stale fries or the fried crumblings.
Provide an Alternative Treat for Visitors
If you have a backyard flock you probably already realize how they attract visitors. Kids walking by love to look at birds and give treats; they usually give candy from their lunches or other things your birds do not need. If you have this issue, provide a little covered bucket next to the coop so that visitors can give regular feed to your chickens (similar to feeders available for ducks at many zoos).
When this is a Monday through Friday issue be sure to calculate that amount as a part of your hens' daily ration.
Remove Artificial Lights
Not everyone will be facing this issue but if you have a coop in your backyard and it is set up so that street or porch lights are leaking into your house your birds will get up during the night and eat.
That is not natural. Birds eat a lot during the day because they sleep all night without eating. (Which is why broiler producers keep the lights on all the time.)
Go out and check on your coop at night and make sure it is totally dark inside. Birds do not need the lights coming in.
Can I Try Anything Else?
Your chickens can also be confined and put on a stricter diet, about half a cup per day per bird for a medium-sized chicken like the Rhode Island Red. Although it goes against the recommendation I made above to provide more exercise, confined birds are only able to eat what you give them. (In my case I keep corn down all the time for my free-range Muscovy ducks and the chickens hover around the feed bins and eat even what they do not need.)
If you use a commercial ration that is not high in calories and fat, then the chickens will eventually lose weight. Production may go down some, but then again fat chickens produce fewer eggs. Don't worry about it.
Your chickens are almost certainly going to live longer so in the long run the number of eggs will even out.
(1) Chen CY, Huang YF, Ko YJ, Liu YJ, Chen YH, Walzem RL, Chen SE. Obesity-associated cardiac pathogenesis in broiler breeder hens: Development of metabolic cardiomyopathy. Poult Sci. 2017 Jul 1;96(7):2438-2446. https://pubmed.ncbi.nlm.nih.gov/28339731/
(2) Walzem RL, Chen SE. Obesity-induced dysfunctions in female reproduction: lessons from birds and mammals. Adv Nutr. 2014 Mar 1;5(2):199-206. https://pubmed.ncbi.nlm.nih.gov/24618762/
(3) Cadmus, K. J., Mete, A., Harris, M., Anderson, D., Davison, S., Sato, Y., Helm, J., Boger, L., Odani, J., Ficken, M. D., & Pabilonia, K. L. (2019). Causes of mortality in backyard poultry in eight states in the United States. Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc, 31(3), 318–326. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6838705/
(4) Davis JE, Cain J, Small C, Hales DB. Therapeutic effect of flax-based diets on fatty liver in aged laying hens. Poult Sci. 2016 Nov 1;95(11):2624-2632. https://pubmed.ncbi.nlm.nih.gov/27143762/
Wakenell P. (2016). Management and medicine of backyard poultry. Current Therapy in Avian Medicine and Surgery, 550–565. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7152007/
This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.