Ross 308 vs Cobb 500: which to place
Cobb is roughly half of Pakistani broiler production and Ross about 15%. The published FCR comparisons disagree — here is what actually decides it.
These are the two strains every new farmer is told to choose between, usually with strong opinions attached and very little evidence. The honest position is narrower than either camp claims.
What the market has already decided
Published value-chain research puts Pakistani broiler production at roughly:
| Strain | Share | | --- | --- | | Cobb 500 | ~50% | | Hubbard | ~25% | | Ross 308 | ~15% | | Arbor Acres | ~10% |
Two things follow. First, Cobb dominates here — if you assumed Ross led because it leads in many other markets, that assumption is wrong for Pakistan. Second, the real contest by volume is Cobb against Hubbard, not Cobb against Ross.
Where they genuinely differ
Cobb 500 carries more weight and more breast. Published comparisons give it the highest body weight, carcass yield and breast meat weight of the common strains, and the highest daily gain — around 39.8 g/day in one Pakistani trial.
Ross 308 is selected hard for feed efficiency, and has the larger body of published performance data to benchmark against.
The part most advice gets wrong
The usual claim is that Ross converts feed better. Published trials disagree. One Pakistani comparison put Ross at FCRFeed conversion ratio — kilograms of feed to put on a kilogram of live weight. The single most useful number in broiler production, because feed is 60–75% of what the bird cost.Glossary → 1.64 against Cobb at 1.70 at 35 days. Other work comparing the two found Cobb returning the better conversion throughout the trial period.
Do not choose a strain on a single FCR claim, including one on this site. Trial results move with diet, climate, housing and sex, and the difference between strains is smaller than the difference between a well-run shed and a badly-run one.
What should actually decide it
Who your buyer is. If you are paid per kilo live and your buyer wants weight, Cobb’s advantage is real and immediate. If you are supplying a processor paying for breast yield, the same argument holds harder.
What your cost sheet punishes. FeedونڈاwandaThe standard term. ‘Wanda rate’ is how feed prices are quoted.Glossary → is 60–75% of what a bird costs. If your margin is thin and feed is your binding constraint, a genuine FCR advantage compounds across six cycles a year — assuming you get one.
What your hatchery actually stocks. Chick supply is a real constraint. Planning a cycle around a strain your hatchery does not reliably carry is worse than any performance difference between the two.
Your housing. Under heat stress and in open houses, robustness starts to matter more than headline growth — which is why Hubbard holds a quarter of this market and deserves more consideration than it usually gets.
The practical answer
If you are new, have no processor contract and no strong reason to do otherwise: place what your neighbours place and what your feed mill has formulated around. In Pakistan that is usually Cobb. You will get better advice, better chick availability and better local benchmarks.
Revisit the question once you have six cycles of your own records — at which point you can answer it with your own numbers instead of anyone else’s trial.