Effect of different protein sources on the meat quality of Złotnicka Spotted pigs with particular emphasis of slaughter body weight

The aim of the study was to determine the impact of protein feeding from Fabaceae plants and the final slaughter weight on the quality of meat of native Złotnicka Spotted pigs. The experiment was carried out on 96 fattening pigs (48 barrows and 48 gilts) of the Złotnicka Spotted breed. Animals were divided into 4 feeding groups: group A – control cereal-soybean mixture, and 3 experimental mixtures containing different types of domestic protein sources (groups B - lupin, C - faba beans and D - peas). All diets were isoproteic and isoenergetic within the fattening phase, i.e. grower and finisher. In addition, pigs were fattened to 3 different slaughter weights: 120, 130 and 140 kg. The type of protein had no effect on fattening and slaughter traits. These traits (feed intake [kg], gaily gain during fattening [g/day], mean backfat thickness [mm]) were influenced by the body weight of the pigs at slaughter (p<0.01). It was found a statistically significant interaction effect between feeding group and body weight on the fat, the fatty acid profile of meat (longissimus lumborum) and on oxidative stability (thiobarbituric acid reactive substances - TBARS) of meat. Increasing the slaughter weight to 140 kg affects increasing the fat content (p<0,05) of meat (longissimus lumborum) primarily in groups of pigs fed on cereal-soy mix (A) and faba beans (C). In addition, fat up to 140 kg and feeding with faba beans (C) and peas (D) has a beneficial effect by reducing the proportion of PUFA n-6/n-3 in meat (p<0,05). Finally, the benefit of feeding pigs with faba beans (C) up to a slaughter weight of 140 kg is the reduction of TBARS of meat (p<0,05). In conclusion, increasing the slaughter weight up to 140 kg and the use in the feed mixture of faba beans improves the nutritional value and oxidation durability of pork.