Cottonseed Meal

The gossypol in cottonseed is present as a free, biologically active form and a bound form associated with protein. What matters in feed is the free fraction, and processing conditions influence how much of the total remains free: heat during processing binds gossypol to protein, reducing the free fraction — but the same heat, applied harder, damages protein quality. The processor is therefore working between two failure modes, and the meals that reach the market differ accordingly.

Free gossypol

The biologically active fraction, the one feed rules and contracts concern themselves with.

Bound gossypol

Gossypol complexed with protein during processing, and not biologically active in the same way.

Expeller versus extracted

Pressing alone leaves more residual oil and a different heat history than pressing followed by solvent extraction, which affects both energy value and the free gossypol outcome.

Cottonseed meal goes chiefly to beef and dairy cattle, where rumen function affords substantial tolerance and the meal’s protein is well used. Its fibre content is higher than dehulled soybean meal’s, because hull is not always fully removed before crushing, and lower-fibre and higher-fibre grades exist depending on the degree of dehulling.

In pig and poultry diets the meal is used sparingly or not at all, and where it is used, the level is a decision made against the applicable feed rules and the free gossypol content of the specific lot — not against a general figure for the ingredient.

Meal ships in bulk and in bags and is often pelleted. It is hygroscopic and will cake and heat if held moist, and expeller grades carrying more residual oil have shorter keeping quality. Meal that has heated in store has lost protein availability, and for this material the heat history is doubly consequential: it bears on gossypol binding as well as on protein quality.