Short answer: on a good Pakistani farm a broiler should weigh about 170–185 g at day 7, 850–950 g at day 21 and 2,000–2,200 g at day 35. The Ross 308 breeder target is higher: 213 g, 1,012 g and 2,296 g. Weigh every week, and treat day 7 as the most important weigh-in of the crop.
Modern broiler strains are bred to a curve. Hit the curve and the cycle pays; drift under it and no last-week miracle brings the weight back. The trap is that a flock two days behind looks perfectly healthy — only the scale tells the truth. At Vital Feeds (Private) Limited, our mill team asks farmers for one thing first when a flock is slow: the weekly weights.
What is the normal broiler weight by age?
Use your breed's own supplement as the final word (Ross and Cobb both publish them — see the Aviagen technical centre). The table shows the Ross 308 as-hatched (mixed male and female) targets from the breeder's 2022 performance objectives, next to our working guide for good Pakistani farm conditions.
| Day | Ross 308 target (g) | Working range, good PK farm (g) |
|---|---|---|
| 0 | 44 | 40–42 |
| 7 | 213 | 170–185 |
| 14 | 533 | 430–465 |
| 21 | 1,012 | 850–950 |
| 28 | 1,616 | 1,400–1,550 |
| 35 | 2,296 | 2,000–2,200 |
| 42 | 2,998 | 2,650–2,900 |
Aviagen itself says these objectives are reached only under good management, and that hot climates and local feed ingredients can hold average results below them. Summer heat, poor sheds and poor water all pull the numbers down — which is exactly why you weigh instead of guessing. The best benchmark is your own record: write down every flock's weekly weights and compare each new flock with your best one.
Why does the day-7 weight matter so much?
Here is the number most farmers never hear: day-7 weight is the earliest and clearest sign of how the whole crop will go. The Ross 2022 objectives list 7-day live weight as a key point to monitor, and an Aviagen management tip says a good start should give a 7-day weight of about four times the chick weight at placement. A 42 g chick should therefore be close to 170 g or more at one week. A chick that is behind at day 7 is fighting for the rest of the cycle.
That is why brooding — temperature, water access in the first hours, fine crumb feed — is where the money is made. The Ross pocket guide sets a target that at least three in four chicks have a full crop two hours after placement, and almost all of them by 24 hours. Our broiler brooding temperature guide covers the first four weeks step by step.
How do I weigh broilers so the number means something?
The Ross Broiler Pocket Guide (2025) gives simple rules that any farm can follow:
- Weigh at the same time of day each week, before a main feed.
- Up to day 21, weigh birds in groups in a bucket on a hanging scale. Weigh at least 100 birds, or 1 in every 100 birds in the shed if that is more.
- Take birds from at least three places in the shed — never just near the door.
- Weigh every bird you catch in the pen, not only the big ones, so the sample is fair.
- Record the average and the spread. A flock that averages on target but has a quarter of its birds small is a problem hiding inside a good number.
After day 21, weigh birds one by one if you can. That shows how even the flock is, which matters as much as the average when the trader comes to buy.
My flock is behind the curve. What should I check first?
Do not reformulate first. Behind-target flocks are usually drinking or breathing badly, not eating the wrong ration. Work through the seven FCR checks — water flow at the far drinkers, fines in the pans, feeder space, temperature, ammonia — and in summer add the heat-stress feeding routine. Nine times out of ten the curve comes back without touching the formula.
- Water: compare the water meter with our broiler water chart. Less water always means less feed eaten.
- Feed eaten: compare intake with the broiler feed per bird chart. Eating the chart amount but gaining less points to health, heat or feed quality.
- Feeder space: the Ross guide allows 45–80 birds per pan feeder, with fewer birds per pan once they pass 3.5 kg.
- Health: if birds look dull, droppings change or deaths rise, call your vet the same day.
Which feed programme matches the weight curve?
A three-stage programme — starter crumbs to about day 10, grower pellets to about day 24, then finisher — exists precisely because the bird's needs change faster than most feeding habits do. The Ross guide notes that starter can be fed for up to 14 days if target weights are not reached. Blend stage changes over two to three days. Our broiler starter, grower and finisher are milled batch-coded in Arifwala with lab-tested maize and soybean meal, so the ration you feed in week five is the same as the one that worked in week one.
Flock stuck under the curve and you cannot find why? Send the mill your weights on WhatsApp — real numbers get real answers. You can also find a Vital Feeds dealer near you.
Written by Waqas Rafiq, CEO, Vital Feeds (Private) Limited.
See our broiler feed in Pakistan and the wider poultry feed range, or message the mill on WhatsApp (UAN 0311 1555136) with your flock's weekly weights.