The Effect of Hydrothermally Processed Soybean- and Rapeseed-Based Diets on Performance, Meat and Carcass Quality Characteristics in Growing-Finishing Pigs

The experiment was performed on 60 crossbred weaners with average initial body weight (BW) of 22 kg. The animals were divided into 4 groups, with 15 animals (10 males and 5 females) per group, based on the percentage content of the following components in complete diets: soybean meal, toasted full-fat soybeans, cold-pressed rapeseed cake with increased oil content, extruded rapeseed cake with increased oil content. The growth performance of pigs, carcass characteristics, meat quality and the fatty acid profile of depot fat were determined. The pigs fed complete diets containing toasted soybeans had higher average daily gain (ADG). The animals receiving cold-pressed rapeseed cake were characterised by lower ADG and higher FCR. The carcasses of pigs fed diets containing cold-pressed rapeseed cake and extruded rapeseed cake had lower lean content than the carcasses of pigs administered toasted soybeans. The analysed feedstuffs had no effect on back-fat thickness or meat quality. Cold-pressed and extruded rapeseed cake contributed to changes in the fatty acid profile of backfat, including an increase in the concentrations of monounsaturated fatty acids (MUFAs) and a more desirable n-6/n-3 PUFA ratio. The extrusion processing of rapeseed cake decreased the content of lysine and methionine with cystine by approximately 4%, and reduced total glucosinolate content by approximately 17%. The inclusion of toasted soybeans in pig diets contributed to higher BW gain and carcass dressing percentage. Rapeseed cake with increased oil content led to desirable changes in the fatty acid profile of backfat.