The perfect pullet: weight curve, uniformity, lighting programme during rearing
Everything a layer house will give over a year is decided before the first egg. A pullet that reaches 18 weeks at the right weight, in a uniform flock, with a lighting programme that was respected, will come into lay quickly, hold her peak and keep strong shells until culling. A late pullet or an uneven flock will give a soft curve that nothing will recover. This lesson takes pullet rearing to the technician's level: we measure, we calculate, we decide week by week.
14 min read · 5-question quiz at the end
By Abdul Hussein ChoumanFounder of NEXTEKCI · Agnibilékrou hatchery since 2006This lesson is part of Laying hens, expert level specialisation. It opens to every registered student, from free registration. Levels 1 to 5 and the tracks remain readable by everyone.
Everything a layer house will give over a year is decided before the first egg. A pullet that reaches 18 weeks at the right weight, in a uniform flock, with a lighting programme that was respected, will come into lay quickly, hold her peak and keep strong shells until culling. A late pullet or an uneven flock will give a soft curve that nothing will recover. This lesson takes pullet rearing to the technician's level: we measure, we calculate, we decide week by week.
- ✓Build and read the weight curve of a flock of pullets, and quantify a delay
- ✓Calculate the uniformity of a flock (percentage within the range and coefficient of variation) and act on an uneven flock
- ✓Run the rearing lighting programme in an open-sided house, and decide the date of the first stimulation
- ✓Prepare the pullet for lay: skeleton, feed, water, calm
- What we call a perfect pullet
- The weight curve: the roadmap of the first 18 weeks
- Uniformity: a flock that comes into lay as one block
- The rearing lighting programme in an open-sided house
- Preparing the pullet for lay: skeleton, feed, water, calm
- Going further
- •Perfect pullet = target weight at 18 weeks (1,480 to 1,580 g), uniformity ≥ 80% (ideally 85%, CV ≤ 8%), lighting programme never increasing before stimulation.
- •Delay = (target − measured) ÷ target × 100; under 3% normal, 3 to 5% we act, over 5% serious; a delay before 8 weeks marks the frame for life.
- •Uniformity: % of pullets within ± 10% of the average, and CV = standard deviation ÷ average; sort the light ones into a separate pen below 80%.
- •In an open-sided house: natural day from 13 to 18 weeks with no lamp at all; first hour when weight ≥ 1,480 g AND uniformity ≥ 80%.
- •Pre-lay (calcium 2 to 2.5%) at the red comb, 16-17 weeks; vaccination = the area veterinarian's programme, finished 2 weeks before transfer.