Full replacement of soybean meal with soybean press cake in diets for pigs intended for long-cured dry ham production

The study investigated whether the full replacement of chemically solvent-extracted soybean meal (SM) with mechanically extracted soybean press cake (SC) could be carried out in pigs intended for dry-cured ham production. Eighty Italian heavy pigs were fattened and finished up to a body weight of 165 kg, with half being fed a commercial diet containing SM and the other half fed an isoenergetic and isonitrogenous diet in which SC fully replaced SM. Growth parameters, carcass traits, fresh meat and cured ham quality, and fatty acid composition were analyzed. Thighs were processed according to the Parma ham production rules, which require a long curing period. The only noteworthy differences observed concerned an increase in polyunsaturated fatty acid levels in the subcutaneous fat of the SC group compared with the SM group (17.26 vs. 14.58%, p < 0.05, in fresh thighs and 15.83 vs. 12.14%, p < 0.01, in cured hams), and particularly in linoleic acid (14.85 vs. 13.01%, p < 0.01 in fresh thighs and 13.72 vs. 10.64%, p < 0.01 in cured hams), which is consistent with general nutritional recommendations favoring unsaturated over saturated fatty acids. These modifications did not affect the final quality, oxidative stability, or visual appearance of the long-cured hams. In conclusion, soybean cake–based diets can be applied throughout the production cycle of heavy pigs; however, higher inclusion levels should be carefully managed, as they may affect parameters related to suitability for dry curing.