How much feed does a laying hen need per day?

A commercial laying hen in peak production typically consumes 100-120 g of complete feed per day, but the NRC (1994) formula ties feed intake directly to metabolisable energy need — which depends on body weight, housing temperature, and egg mass produced. At 20 degrees C, a 2 kg hen laying at 85% with 62 g eggs needs roughly 113 g of a 2,800 kcal/kg layer pellet per day. Cold housing raises ME need; heat above 20 degrees C reduces feed intake but the bird still needs the same nutrients in less feed volume.

How much water do chickens drink per day?

As a rule of thumb, chickens drink about 1.7-2.0 ml of water per gram of feed consumed at thermoneutral temperature. A flock eating 110 g/bird/day therefore needs roughly 190-220 ml per bird. Heat stress increases demand sharply — the calculator adds 10% extra per degree Celsius above 20 degrees C, consistent with industry guidance. Always size drinker capacity to at least twice the calculated daily need.

What is the NRC laying-hen ME equation?

The NRC (1994) Nutrient Requirements of Poultry gives daily ME intake (kcal/bird/day) = BW^0.75 * (173 - 1.95 * T) + 2.07 * egg_mass_g, where BW is body weight in kg, T is ambient temperature in degrees C, and egg_mass_g is egg mass in grams per bird per day. The 0.75 exponent (metabolic body weight) accounts for the non-linear scaling of maintenance energy with body size. The 2.07 factor represents the ME cost of synthesising one gram of egg mass.

How much calcium does a laying hen need?

The NRC (1994) recommends 3.4% calcium in the total diet for peak-production layers, rising slightly to 3.7% for older hens producing larger eggs. Most of this calcium goes directly into eggshell — a single 62 g egg contains about 2.2 g of calcium. Commercial feeds typically supply calcium via limestone or oyster shell at roughly 8-10% of the premix. If your feed shows a red calcium badge, adding a small amount of coarse limestone or crushed oyster shell in a separate free-choice feeder is the standard fix.

What FCR should broilers achieve?

Feed conversion ratio (FCR) benchmarks from Aviagen for the Ross 308 broiler are: starter phase (0-3 weeks) around 1.4 kg feed per kg live-weight gain; grower phase (3-6 weeks) around 1.7; finisher phase (6 weeks to slaughter) around 1.9. Overall batch FCR from day 1 to 42-day slaughter is typically 1.75-1.85. Higher FCR means more feed per kg of meat, which raises cost. Poor litter quality, disease pressure, and suboptimal stocking density are the main drivers of FCR deterioration on real farms.

What is the difference between ME and CP in chicken nutrition?

Metabolisable energy (ME) is the fuel that powers all bodily functions — maintenance, movement, egg synthesis, and muscle growth. It is measured in kcal per kg of feed. Crude protein (CP) is the total nitrogen-containing fraction of the diet, which the bird uses to build muscle, feathers, and eggs. Providing enough ME but too little CP stunts growth and reduces egg production; excess CP wastes money and increases nitrogen excretion. Both must be balanced to the specific production stage, which is why the calculator checks each nutrient independently.

How do I calculate the break-even laying rate?

The break-even laying rate is the minimum percentage of hens that must lay each day for egg revenue to cover feed costs. The calculator divides total daily feed cost by the revenue from one full day of laying (birds divided by 12 times price per dozen) and expresses the result as a percentage. For example, 50 hens eating £2.09/day of feed at a selling price of £1.40/dozen need at least 36% of hens laying to break even on feed alone — well below commercial targets of 85%+, confirming a healthy margin at typical production rates.

Chicken Feed Calculator

Knowing exactly how much to feed your chickens — and whether that feed actually meets their nutritional needs — is the difference between a thriving flock and one that under-produces, suffers from soft shells, or racks up avoidable feed costs. This calculator applies the NRC (1994) Nutrient Requirements of Poultry equations to give you precise daily feed intake, water needs, ME and CP requirements, a six-nutrient adequacy check, and (for laying flocks) a full egg economics breakdown — all instantly in your browser.

How it works

For laying hens, the tool uses the NRC (1994) metabolisable energy intake equation:

ME (kcal/bird/day) = BW^0.75 * (173 - 1.95 * T) + 2.07 * egg_mass

where BW is body weight (kg), T is ambient temperature (degrees C), and egg_mass is grams of egg produced per bird per day (laying rate times egg weight). The 0.75 power converts body weight to metabolic body weight, which correctly scales maintenance energy across different bird sizes. Feed intake is then back-calculated from the feed’s ME density — so if you switch from a 2,800 kcal/kg pellet to a 2,500 kcal/kg feed, the calculator automatically increases the intake needed to deliver the same energy.

Daily crude protein need uses the companion NRC equation:

CP (g/bird/day) = 4.5 * BW^0.75 + 0.20 * egg_mass

For broilers, pullets, starters, and breeders the tool uses NRC-tabulated percentage requirements per production class, then scales feed intake upward if the chosen feed has lower ME density than the class minimum.

Water need is estimated from the industry standard 1.7-2.0 ml per gram of feed consumed, with a 10% per-degree heat-stress correction above 20 degrees C (NRC 1994, Chapter 6).

Worked example — 50 free-range layers

Suppose you run 50 free-range layers at 2.0 kg body weight, a housing temperature of 15 degrees C, an 80% laying rate, and 63 g eggs. You feed a layer pellet at £380/tonne.

Egg mass per bird = 0.80 * 63 = 50.4 g
ME need = 2.0^0.75 * (173 - 1.95 * 15) + 2.07 * 50.4 = 1.68 * 143.75 + 104.3 = 345.8 kcal/bird/day
Feed intake = 345.8 / 2800 * 1000 = 123.5 g/bird/day
CP need = 4.5 * 1.68 + 0.20 * 50.4 = 7.56 + 10.08 = 17.6 g/bird/day
Flock daily feed = 123.5 g * 50 = 6.2 kg
Daily feed cost = 6.2 * £0.38 = £2.36
Daily eggs = 0.80 * 50 = 40 eggs = 3.33 dozen
Daily revenue at £1.40/dozen = £4.67
Daily profit (feed only) = £4.67 - £2.36 = £2.31

At cold-snap temperatures (5 degrees C), ME need rises to 382 kcal/bird/day and feed intake climbs to 136 g — increasing annual feed cost by about £105 for the flock.

Feed ingredient reference

The calculator includes 23 ingredients ranging from raw grains (wheat, maize, barley, sorghum) and protein meals (soybean, rapeseed, fishmeal, meat-and-bone meal) to fat sources, calcium supplements (limestone, oyster shell, dicalcium phosphate), and complete commercial pellets. Each entry carries ME (kcal/kg as-fed), CP %, Ca %, available P %, Lysine %, and Met+Cys % values drawn from NRC (1994) Table B-1 and AHDB 2024 UK feed composition data, with indicative prices as of 2024.

Formula note

All ME values are on an as-fed basis. The calcium requirement jumps sharply at point-of-lay (from around 0.9% for growing pullets to 3.4-3.7% for laying hens) because each egg requires approximately 2.0-2.2 g of calcium. Failing to meet this requirement forces the hen to mobilise bone calcium, leading to cage layer fatigue and reduced shell quality. The calculator flags this with a red badge and suggests adding limestone or oyster shell.