- ✓Organise a reliable weighing: sample, method, regularity
- ✓Compare the average weight with the benchmarks and calculate uniformity
- ✓Decide from the curve: look for the cause of a delay, set the selling date
A reliable weighing
- When: the same day every week, at the same time, preferably in the morning before the feed is given out.
- How many: at least 50 to 100 birds per house (or 2 to 5% of the flock), taken from three different places (never only near the door, where you catch the slowest ones).
- How: on day 7 and day 14, you weigh in groups (10 chicks in a bucket, weight divided by 10). After that, individually, with a hook scale or a platform scale, in a bucket or a net. Catch them by both legs, calmly, without running through the flock.
- Record: each weight, then the average, on the record sheet. A weighing notebook is worth its weight in gold when it is time to negotiate.
Weight benchmarks
Benchmarks for a white broiler that is well managed, in an open-sided house in a hot climate (a little below the breeders’ tables, which are produced in controlled houses):
| Age | Average weight (white broiler) | Reading |
|---|---|---|
| Day 7 | 150 to 180 g | About 4 times the weight on arrival |
| Day 14 | 400 to 460 g | Brooding successful if you are there |
| Day 21 | 850 to 950 g | Growing phase |
| Day 28 | 1,350 to 1,500 g | Switch to finisher |
| Day 35 | 1,850 to 2,100 g | Usual selling weight |
| Day 42 | 2,300 to 2,600 g | Beyond this, the feed conversion ratio worsens |
Coloured chickens grow more slowly: count on about 1 kg at around 6 to 7 weeks, 1.8 to 2.2 kg at around 12 to 14 weeks depending on the strain and the feed. For pullets that will become layers, it is the weight at 18 weeks that determines the laying peak: you follow it with the level 5 benchmarks.
Uniformity: is the flock even?
Two flocks with the same average weight can be very different: one regular, the other made up of big and small birds. You calculate uniformity: the share of birds whose weight is within ± 10% of the average. Example: average 1,000 g → you count the birds between 900 and 1,100 g. More than 80% is good; below 70%, there is a problem of access (feeders, drinkers, density), of disease, or sorting to be done.
An uneven flock sells badly: the buyer pays for the small birds at the price of small birds. From 3 weeks, separating the smallest into a pen with their own feeders allows them to catch up.
Reading the curve and deciding
- Behind from day 7: brooding (heat, water, feed, transport). You correct it for the next flock; on this one, you make sure everything is in place.
- A break between two weighings: something happened this week: change of feed, heat stress, disease starting, water. Look in the week’s record sheet.
- Growth slowing at the end of the flock despite the feed: it is the signal to sell, the feed conversion ratio is worsening.
- Selling date: with the curve, you tell the buyer “2 kg around day 36” one week in advance, instead of finding out on the day itself.
For the entrepreneur
- ›Insist on the written weekly weighing: average weight, uniformity, number weighed. Without it, the selling date and the price are decided blindly.
- ›Compare each flock with the previous one, at the same week: that is how you will know whether the farm is making progress.
- ›An uneven flock = money lost at the sale; ask for the small birds to be sorted out from three weeks.
For the technician
- ›Weighing on the same day, at the same time, 50 to 100 birds from three places, before feeding; everything is recorded.
- ›Calculation of the average and the uniformity (± 10%); small birds separated and fed apart from 3 weeks.
- ›Any break in the curve triggers a search in the week’s record sheet.
The 3 questions to ask your technician this week
- What is this week’s average weight, out of how many birds weighed, and what is the uniformity?
- Are we ahead of or behind the benchmarks, and why?
- On what day do we expect to reach the selling weight, and has the buyer been told?
Key points
- •Weekly weighing: same day, same time, before feeding, 50 to 100 birds from three places.
- •White broiler benchmarks: ≈ 160 g at 7 days, 430 g at 14 days, 900 g at 21 days, 1.4 kg at 28 days, 2 kg at 35 days.
- •Uniformity = share of birds within ± 10% of the average; more than 80% is good.
- •A break in the curve is looked for in the week’s record sheet; slowing growth at the end of the flock = sell.
- •The curve sets the selling date and lets you warn the buyer one week in advance.