This broiler growth chart reproduces the 2022 Cobb 500 and Ross 308/308 FF as-hatched weight and cumulative feed conversion objectives at weekly intervals. Use the reference that matches your placed birds, and review your integrator's targets before making a flock or budget decision.
Jump to: Cobb 500 chart · Ross 308 chart · Using the chart
Cobb 500 Growth Chart: 2022 Metric As-Hatched Objectives
Source: Cobb-Vantress, Cobb500 Broiler Performance & Nutrition Supplement (2022), PDF page 4, printed page 2.
| Age | Weight (g) | Weight (lb) | Weekly gain (g) | Cumulative FCR |
|---|---|---|---|---|
| 0 days | 42 g | 0.09 lb | — | — |
| 7 days | 202 g | 0.45 lb | 160 g | 0.891 |
| 14 days | 570 g | 1.26 lb | 368 g | 1.029 |
| 21 days | 1,116 g | 2.46 lb | 546 g | 1.182 |
| 28 days | 1,783 g | 3.93 lb | 667 g | 1.322 |
| 35 days | 2,521 g | 5.56 lb | 738 g | 1.441 |
| 42 days | 3,278 g | 7.23 lb | 757 g | 1.555 |
| 49 days | 4,001 g | 8.82 lb | 723 g | 1.686 |
Ross 308/308 FF Growth Chart: 2022 As-Hatched Objectives
Source: Aviagen, Ross 308/308 FF Broiler Performance Objectives (2022), PDF page 4, printed page 3.
| Age | Weight (g) | Weight (lb) | Weekly gain (g) | Cumulative FCR |
|---|---|---|---|---|
| 0 days | 44 g | 0.10 lb | — | — |
| 7 days | 213 g | 0.47 lb | 169 g | 0.780 |
| 14 days | 533 g | 1.18 lb | 320 g | 1.005 |
| 21 days | 1,012 g | 2.23 lb | 479 g | 1.142 |
| 28 days | 1,616 g | 3.56 lb | 604 g | 1.269 |
| 35 days | 2,296 g | 5.06 lb | 680 g | 1.399 |
| 42 days | 2,998 g | 6.61 lb | 702 g | 1.531 |
| 49 days | 3,681 g | 8.12 lb | 683 g | 1.663 |
Units, Weekly Gain, and FCR Definitions
Gram weights and FCR are transcribed from the metric source tables. Pounds are calculated using 453.59237 grams per pound and rounded to two decimal places; they are not copied from the breeders' separate imperial tables. Weekly gain is the difference between the two displayed weights seven days apart, not the breeder's daily-gain column. Day-0 FCR and weekly gain are blank in the sources and shown here as a dash.
Cumulative FCR is feed consumed divided by live body weight in these references, not feed divided by weight gain after subtracting chick weight. Cobb's footnote says feed conversion does not account for mortality. Ross specifies on-farm body weight including feed in the intestinal tract, feed consumption per living bird, and FCR that includes initial body weight at placement and does not account for mortality. Rounded source values can create small differences when you recalculate a ratio.
Commercial settlement FCR may use different mortality, feed-inventory, or live-weight adjustments. Compare like-for-like definitions before treating a difference as a feed-cost problem. See the FCR calculation guide for the information to collect.
How to Use a Broiler Growth Chart
- Match the reference: Check the strain, feathering variant, sex mix, placement date, and the breeder edition used by your integrator. Do not substitute the Ross 308 AP table for Ross 308/308 FF.
- Check the measurement: Follow your integrator's or breeder's weighing protocol, use a checked scale, record the sample count, and keep timing and house coverage consistent. Record the weighing conditions so repeated samples are comparable.
- Record the difference: Compare average sample weight with the relevant age objective. Calculate percentage difference as (measured weight minus reference weight) / reference weight × 100. A difference alone does not identify its cause.
- Review the flock with your adviser: Take the weight history, feed records, and health observations to your field technician or veterinarian. Agree on any management or catch-date changes with the responsible adviser and integrator.
- Review the financial effect: Use your contract's payment basis and actual feed and operating costs to assess the effect on margin. Extra days can add costs; a breeder table alone cannot tell you whether extending the flock will improve your payout.
There is no universal farm-average discount or automatic intervention threshold in this article. Farm conditions, health, sampling, sex mix, feed, and contract terms can change the comparison. These tables should support a discussion, not replace flock-specific advice.
Recording Growth and Costs in PoultryLog™
PoultryLog™ lets growers record sample weights, feed deliveries, mortality, income, and expenses alongside flock records. Keep a dated weight history and review recorded costs and flock performance when deciding what to discuss with your field technician. The reference tables above are an article resource; this article does not promise automatic breed-curve matching or a breed-target alert.
Written and corrected by Samuel Howell, PoultryLog™ product maintainer. The numerical tables were checked against the linked breeder PDFs on October 11, 2026. Independent qualified poultry review is pending; this is a source-based reference, not veterinary or farm-specific management advice.
Correction and revision log- 2026-10-11: Corrected every displayed Cobb 500 and Ross 308/308 FF weekly weight and FCR to the 2022 metric as-hatched tables, corrected placement age to day 0, and recalculated pounds and weekly gains. For example, Cobb day 28 is 1,783 g rather than 1,620 g, and day 42 is 3,278 g rather than 2,910 g. Added direct page citations and FCR definitions. Removed unsupported field-average ranges, strain rankings, management thresholds, and automatic breed-alert claims. Added an honest author and review status.
- 2026-10-06: Added chart jump links and trial links.
- 2026-09-03: Added separate breeder tables.
- 2024-01: Initial version.