Ross 308 broiler weight chart (day by day)

Target body weight, feed per bird and FCR for Ross 308, day 0 to day 56. As-hatched, metric, from Aviagen’s 2022 performance objectives.

برائلر وزن چارٹ: روزانہ وزن، فیڈ اور FCR

Key targets As-hatched, 2022 breeder table.

Day 7: 213 g FCR 0.780
Day 21: 1,012 g FCR 1.142
Day 35: 2,296 g FCR 1.399
Day 42: 2,998 g FCR 1.531

Ross 308 growth curve and FCR by age

Target live weight in grams, day 0 to day 56. Squares mark the end of each week.

Ross 308 · Targets at the end of each week
Day	Weight (g)	Gain that week (g)	Feed that week (g)	Cum. FCR
0	44	—	—	—
7	213	169	166	0.780
14	533	320	369	1.005
21	1,012	479	620	1.142
28	1,616	604	896	1.269
35	2,296	680	1,160	1.399
42	2,998	702	1,375	1.531
49	3,681	683	1,529	1.663
56	4,318	637	1,618	1.793

Gain and feed that week are worked out from the breeder table: the change since the end of the week before.

Ross 308 weight and feed consumption per day

Ross 308 · Target weight, feed and FCR, days 0 to 28
Day	Weight (g)	Daily gain (g)	Feed that day (g)	Cum. feed (g)	Cum. FCR
Placement
0	44	—	—	—	—
Week 1 · days 1 to 7
1	62	18	12	12	0.196
2	81	19	16	28	0.352
3	102	21	20	48	0.476
4	125	23	24	72	0.577
5	151	26	28	100	0.658
6	181	30	31	131	0.724
7	213	32	35	166	0.780
Week 2 · days 8 to 14
8	249	36	40	206	0.826
9	288	39	43	249	0.865
10	330	42	48	297	0.900
11	376	46	52	349	0.930
12	425	49	57	406	0.957
13	477	52	62	468	0.982
14	533	56	67	535	1.005
Week 3 · days 15 to 21
15	592	59	73	608	1.026
16	655	63	77	685	1.047
17	720	65	83	768	1.066
18	789	69	88	856	1.086
19	860	71	94	950	1.105
20	935	75	100	1,050	1.123
21	1,012	77	105	1,155	1.142
Week 4 · days 22 to 28
22	1,092	80	111	1,266	1.160
23	1,174	82	117	1,383	1.178
24	1,258	84	122	1,505	1.196
25	1,345	87	128	1,633	1.214
26	1,434	89	134	1,767	1.233
27	1,524	90	140	1,907	1.251
28	1,616	92	144	2,051	1.269

Ross 308 · Target weight, feed and FCR, days 29 to 56
Day	Weight (g)	Daily gain (g)	Feed that day (g)	Cum. feed (g)	Cum. FCR
Week 5 · days 29 to 35
29	1,710	94	151	2,202	1.288
30	1,805	95	155	2,357	1.306
31	1,901	96	161	2,518	1.325
32	1,999	98	166	2,684	1.343
33	2,097	98	171	2,855	1.362
34	2,196	99	176	3,031	1.381
35	2,296	100	180	3,211	1.399
Week 6 · days 36 to 42
36	2,396	100	185	3,396	1.418
37	2,496	100	188	3,584	1.437
38	2,597	101	193	3,777	1.456
39	2,697	100	197	3,974	1.474
40	2,798	101	201	4,175	1.493
41	2,898	100	204	4,379	1.512
42	2,998	100	207	4,586	1.531
Week 7 · days 43 to 49
43	3,097	99	211	4,797	1.550
44	3,197	100	213	5,010	1.569
45	3,295	98	216	5,226	1.587
46	3,393	98	219	5,445	1.606
47	3,490	97	221	5,666	1.625
48	3,586	96	224	5,890	1.644
49	3,681	95	225	6,115	1.663
Week 8 · days 50 to 56
50	3,776	95	227	6,342	1.681
51	3,869	93	229	6,571	1.700
52	3,961	92	230	6,801	1.719
53	4,052	91	231	7,032	1.738
54	4,142	90	233	7,265	1.756
55	4,230	88	233	7,498	1.775
56	4,318	88	235	7,733	1.793

About this table

Weight, cumulative feed and cumulative FCR are copied from the breeder’s 2022 table, as-hatched and metric.
Daily gain and feed that day are the change from the day before. We worked them out; they are not in the breeder’s table.
Cumulative feed is the total grams one bird has eaten up to that day. Cumulative FCR is the breeder’s own figure. It is close to that feed divided by the bird’s weight on the same day, but not always equal to it.

Source Aviagen, Ross 308 / 308 FF Broiler Performance Objectives 2022 (as-hatched, metric). aviagen.com

These are breeder targets, not a promise. Real flocks change with weather, feed, health and care.

The page prints without the menus and buttons: the title, the source and both tables. Choose “Save as PDF” in the print window to keep a copy.

How to weigh a sample of birds

The chart only helps if your own figure is fair to the whole shed.

Weigh at the same time of day each time, so the birds’ crops are in the same state.
Catch birds from the front, the middle and the back of the shed, not only the easy ones near the door or the feeders.
Weigh the same number of birds each time, from the same places, so this week’s average can be set beside last week’s.
Write down each weight. Add them up and divide by the number of birds. That is the sample average.
Note the lightest and the heaviest bird too. A wide spread means the flock is growing unevenly.

In Poultry Ledger

Press W on Today’s Log and enter the sample’s average weight, with the lightest and heaviest bird, in grams.

Set the flock’s breed to Ross 308 and the app shows its weight beside the target for that day. Every sample is kept, so you can see the trend.

How to compare your flock with the chart

Work out the flock’s age in days. The day the chicks were placed is day 0.
Find that day in the table and set your sample average beside the target weight.
Look at the gain over the last week, not only today’s weight. Set it beside the “gain that week” column.
If you know the feed used, work out your FCR with the calculator and compare it with the FCR for the same day.
If the flock is behind, check that the feed bags were really eaten, then look at water, heat, stocking and health.

example farm FLOCK-2026-013 · Ross 308

Example: one sample, one target

Age: day 23
Sample average: 1,240 g
Ross 308 target: 1,174 g
Difference: +66 g · +5.6%

Ahead of the target for its age.

Work out your FCR

Ross 308 vs Cobb 500

Ross 308 Cobb 500 Target live weight in grams, day 0 to day 56, both breeds.

Ross 308 is the heavier table up to day 9. From day 11 the Cobb 500 table is heavier every day.
From day 21 to day 35 the Cobb 500 target is about 10% heavier: 2,521 g against 2,296 g at day 35.
The Cobb 500 target FCR is higher on every day that both tables give one: 1.441 against 1.399 at day 35.
These are two breeders’ own targets on their own feeding programmes, not a trial on one farm. Compare your flock with the table for the breed you placed.

Ross 308 and Cobb 500 targets at the end of each week
Day	Ross 308 (g)	Cobb 500 (g)	Cobb − Ross (g)	Cobb − Ross (%)	Ross 308 FCR	Cobb 500 FCR
0	44	42	−2	−4.5%	—	—
7	213	202	−11	−5.2%	0.780	0.891
14	533	570	+37	+6.9%	1.005	1.029
21	1,012	1,116	+104	+10.3%	1.142	1.182
28	1,616	1,783	+167	+10.3%	1.269	1.322
35	2,296	2,521	+225	+9.8%	1.399	1.441
42	2,998	3,278	+280	+9.3%	1.531	1.555
49	3,681	4,001	+320	+8.7%	1.663	1.686
56	4,318	4,641	+323	+7.5%	1.793	1.842

Ross 308 weight chart questions

What should a Ross 308 weigh at 35 days?

The 2022 as-hatched target is 2,296 g (2.296 kg) at day 35, with a cumulative FCR of 1.399. At day 42 the target is 2,998 g.

How much feed does a Ross 308 eat per day?

It rises with age. The table works out to 35 g per bird on day 7, 105 g on day 21 and 180 g on day 35. By day 35 one bird has eaten 3,211 g in total.

How is the FCR column worked out?

It is the breeder’s cumulative FCR, copied from the table. It is close to cumulative feed per bird divided by body weight on the same day: at day 35, 3,211 ÷ 2,296 = 1.399, and the table gives 1.399. Our FCR calculator takes the chick weight out first, so for the same flock it reads a little higher.

Is this for males, females or a mixed flock?

These are the as-hatched figures: a mixed flock of males and females, as they come from the hatchery.

Why is my flock lighter than the chart?

The chart is the breeder’s target under good conditions. Heat, feed quality, water, stocking and disease all pull real flocks below it. A 2025 study of large farms in Punjab found flocks sold at 37 to 44 days at about 2.34 kg.

Can I print this chart or save it as a PDF?

Yes. Use the “Print this table” button or your browser’s print. The page prints the title, the source and both tables without the menus. Choose “Save as PDF” to keep a copy.

Ross 308 targets at a glance

Day 21: 1,012 g; Target FCR 1.142
Day 35: 2,296 g; Target FCR 1.399
Day 42: 2,998 g; Target FCR 1.531

The breeder’s as-hatched targets: males and females together, as they come from the hatchery.

See every day in the table

Not sure how your flock compares?

Send us your flock’s age and weight on WhatsApp and we will help.

0303-5655167

Put your own flock beside this chart.

Set the flock’s breed to Ross 308 or Cobb 500, record a sample weight, and Poultry Ledger shows the flock against the target for its age. It works offline.

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