Cheese is not bad for chickens in small amounts. Most plain cheeses are safe as an occasional treat, and the calcium and protein they contain can actually support egg production. Problems only arise when chickens eat too much cheese (risking excess fat and sodium) or when they’re given moldy or heavily processed varieties.
What Cheese Offers Chickens
Cheese is a concentrated source of calcium, protein, phosphorus, and B vitamins. A single ounce of hard cheese contains roughly 8 grams of protein and 180 milligrams of calcium. Soft cheeses like cottage cheese pack even more protein per serving, around 14 grams per half cup, with less fat.
Calcium matters for laying hens. It’s the primary building block of eggshells, and hens that don’t get enough produce thin, fragile shells or may stop laying altogether. Research on laying hens fed diets supplemented with skim milk powder found that dairy improved shell thickness and overall egg quality without changing how many eggs the hens produced. Cheese won’t boost your egg count, but the calcium and dairy proteins can contribute to stronger shells when offered alongside a balanced layer feed.
Sodium Is the Biggest Risk
The real concern with cheese is salt. Many cheeses, particularly processed varieties like American cheese, cheese spreads, and flavored cheeses, contain high levels of sodium. Chickens are sensitive to salt. According to the Merck Veterinary Manual, salt toxicosis in poultry causes increased thirst, weakness, diarrhea, difficulty breathing, fluid discharge from the beak, and in severe cases, leg paralysis.
Chickens can tolerate small amounts of salt in their normal diet, but the threshold is low, around 0.25% salt concentration in drinking water. A single slice of processed American cheese can contain over 300 milligrams of sodium, which is a significant dose for an animal that weighs only five to eight pounds and eats about half a cup of feed per day. Stick to lower-sodium options like plain cottage cheese, mozzarella, or Swiss cheese. Avoid anything labeled “processed” or that comes in individual plastic-wrapped slices.
Too Much Fat Causes Real Problems
Cheese is calorie-dense, and chickens that regularly eat high-energy treats with limited exercise are at risk for fatty liver hemorrhagic syndrome. This condition causes fat to accumulate in the liver until blood vessels rupture, often killing the bird suddenly with no warning signs. It’s most common in laying hens fed high-energy diets who don’t move around much, which describes a lot of backyard flocks with small runs.
An ounce of hard cheese contains about 120 calories and 6 grams of saturated fat. For a chicken eating roughly half a cup of feed daily, that’s a substantial caloric addition. The occasional small piece won’t cause problems, but daily cheese treats, especially combined with other high-fat snacks like sunflower seeds or mealworms, can push total energy intake into dangerous territory.
Blue Cheese and Moldy Cheese Are Dangerous
Never feed chickens blue cheese, and throw away any cheese that has developed mold before offering it to your flock. The fungi used to make blue cheese, primarily Penicillium roqueforti, produce toxins called tremorgens, specifically roquefortine and penitrem A. These compounds are neurotoxic and can cause tremors, seizures, loss of coordination, and collapse in animals that consume them. Cream cheese and other high-protein dairy products can also develop these same dangerous molds under refrigeration.
Regular cheese that’s gone moldy in your fridge poses the same risk. The mold you see on the surface often extends deeper into soft cheeses than it appears, so cutting off the visible mold isn’t a reliable safety measure. If it’s moldy, skip it entirely.
How Much Cheese Is Safe
Treats of any kind, cheese included, should make up no more than 10% of a chicken’s daily diet. Since a chicken eats about half a cup of feed per day, that means treats total roughly a tablespoon. For cheese specifically, a few small cubes or a tablespoon of shredded cheese once or twice a week is plenty.
Cottage cheese is one of the best options because it’s high in protein, lower in fat than most hard cheeses, and relatively low in sodium. You can mix a spoonful into other treats like leftover vegetables or cooked grains. Plain shredded mozzarella and Swiss are also good choices. Avoid feta (very salty), blue cheese (toxic molds), and anything heavily processed or flavored.
Best Practices for Feeding Cheese
- Choose plain, low-sodium varieties: cottage cheese, mozzarella, and Swiss are the safest picks.
- Keep portions small: a few thumbnail-sized pieces per chicken, no more than twice a week.
- Skip moldy or blue-veined cheeses entirely: the fungal toxins pose a genuine neurological risk.
- Don’t replace feed with treats: layer feed is nutritionally balanced for egg production. Cheese is a supplement, not a substitute.
- Clean up leftovers: cheese left in a run on a warm day will spoil and grow mold quickly, creating the exact toxin risk you’re trying to avoid.
Most chickens love cheese, and there’s no reason to keep it from them entirely. The key is treating it like what it is: a rich, calorie-dense snack that belongs in small quantities alongside a proper diet.