When exactly should feed change, and why does it matter for later production? Getting this right sits at the core of commercial layer nutrition: layer feed programs move through deliberate shifts, each timed to a stage of skeletal growth, maturity, or egg output. Getting the timing right protects lifetime performance; getting it wrong shows up months later as poor shell quality or a weak peak.
Starter and Grower Feed Build the Frame
To about six weeks, pullets need 19 to 20 percent crude protein for rapid frame growth, fed as a crumble (Lohmann Breeders, 2020; Oregon State University Extension, 2025). Grower feed then takes over with less protein, around 15 to 18 percent depending on strain, building skeleton and organ capacity rather than early fat (Lohmann Breeders, 2020; Oregon State University Extension, 2025).
A sound pullet feed program should never run on a calendar alone. Lohmann is explicit that diet changes are determined by body weight, not age, and that pullets should be weighed at regular intervals (Lohmann Breeders, 2020). Producers tracking this weekly with the BAT1 manual poultry scale catch flocks drifting off the standard curve early enough to fix the ration before uniformity suffers.
Developer and Pre-Lay Diets Prepare the Pullet
Around 16 to 17 weeks, most layer hen feeding programs introduce a developer feed with reduced density and added fibre, conditioning the gut so pullets eat enough once production starts (Lohmann Breeders, 2020). A pre-lay diet then runs for about ten days as pullets approach point of lay, at roughly double the calcium, bridging what would otherwise be a large jump and improving uniformity among late maturers (Lohmann Breeders, 2020). Flocks graded ahead of transfer with automated weight-based sorting respond more predictably to phase-feeding since the house sits closer to one physiological stage at once.
Chicken Layer Feed Replaces Developer at First Egg
The switch to full chicken layer feed should land close to the first egg, generally at three to five percent daily production. Delaying it forces early maturers to draw calcium from bone reserves, a documented driver of higher mortality (Lohmann Breeders, 2020). Layer feed carries more calcium and less protein than developer, reflecting the shift from growth to egg formation. Flocks monitored with the BAT2 Connect automatic scale show this bodyweight shift in near real time, signalling exactly when to change rations.
Calcium Timing and Peak Production
Shell quality depends on calcium particle size as much as total intake. Coarse limestone dissolves slowly and stays available overnight when shells calcify, and trials in hens aged 24 to 68 weeks found it increased shell weight versus fine limestone (Skrivan et al., 2010); Lohmann raises its coarse to fine ratio from 70:30 in early lay to 85:15 after week 70 (Lohmann Breeders, 2020). Formulation into peak must track rising egg mass and continued weight gain together, with phase 1 protein near 18.5 percent tapering through later phases (Lohmann Breeders, 2020), while Hy-Line treats the rear-to-peak transition as its own phase (Hy-Line International, 2020). A well-timed program keeps the layer feed conversion ratio in the 2.0 to 2.2 kilogram range per kilogram of egg mass, the benchmark Lohmann sets for flocks following this phase structure (Lohmann Breeders, 2020). Continuous automated weight monitoring, where birds step onto the scale voluntarily through the day, flags a flock falling behind its curve while there is still time to adjust feed.
What Flock Averages Miss
A flock average can look fine while hiding trouble. In a study of 7,708 hens weighed at 16, 22, and 74 weeks with individual-bird scales, heavy and medium hens showed significantly higher egg follicle production than light hens, alongside more keel damage among the heaviest (Sibanda et al., 2020). Only individual, catch-and-weigh readings surface that split, since averages hide it by design.
Feeding both streams, daily averages and hand-caught checks, into the BAT Cloud data platform benchmarks a flock against the breed’s standard curve continuously, not at scattered checkpoints.
References
Hy-Line International, 2020: W-36 Commercial Layers Management Guide. https://www.hyline.com/filesimages/Hy-Line-Products/Hy-Line-Product-PDFs/W-36/36%20COM%20ENG.pdf
Lohmann Breeders, 2020: Management Guide, Cage Housing, LOHMANN Brown-Classic Layers. https://lohmann-breeders.com/media/strains/cage/management/LOHMANN-Brown-Classic-Cage.pdf
Oregon State University Extension, 2025: How to Feed Your Laying Hens, PNW 477. https://extension.oregonstate.edu/catalog/pnw-477-how-feed-your-laying-hens
Sibanda, T.Z., Kolakshyapati, M., Walkden-Brown, S.W., de Souza Vilela, J., Courtice, J.M., Ruhnke, I., 2020: Body weight sub-populations are associated with significant different welfare, health and egg production status in Australian commercial free-range laying hens in an aviary system. European Poultry Science, 84. https://www.sciencedirect.com/science/article/pii/S000390982500298X
Skrivan, M., Marounek, M., Bubancova, I., Podsednicek, M., 2010: Influence of limestone particle size on performance and egg quality in laying hens aged 24 to 36 weeks and 56 to 68 weeks. Animal Feed Science and Technology, 158. https://www.sciencedirect.com/science/article/abs/pii/S0377840110001069