Effects of Processing on the Nutritional Value of Feeds ( Cottonseed Meal & Soybean Meal )

Cottonseed Meal

Cottonseed meal contains gossypol, a compound with undesirable nutritional qualities. Free gossypol is associated with the pigment gland. Puncturing the pigment gland causes free gossypol to be mixed with other compounds in cottonseed meal and becomes bound. Bound gossypol is less harmful than is free gossypol.
The method used to remove the cottonseed oil affects the gossypol content of the residue which becomes cottonseed meal. Hydraulic pressed and solvent-extracted meals contain higher levels of gossypol than does prepressed solvent meal. Glandless meal has lower levels of gossypol. Treatment of the meal with iron salts eliminates the toxicity of gossypol, but also produces a darker meal which is unacceptable to the feed industry.

Soybean Meal

Heat destroys the trypsin inhibitor. Wet heat is more effective than dry heat.

Linseed Meal

The toxic factor for poultry can be removed by soaking the meal in water for 12-18 hours.