PSXI-25 - Mixed meal replacing soybean meal and its impacts on growth performance, immunity properties, and meat quality of finishing pigs

Abstract: The purpose of this experiment was to evaluate the effects of the mixed meal (MM) on growth performance, carcass traits, meat quality and immunity properties of finishing pigs by partially replacing soybean meal with a mixed meal in the diet. A total of 54 crossbred pigs (Landrace × Large White × Duroc, initial body weight 97.60±0.30 kg) were randomly allotted to one of the following three treatments with six replicates (three pigs/pen). Treatments were 1) a corn-soybean meal diet (SBM, 12.5% CP); 2) a corn-soybean meal-mixed meal diet (SMM, 12.5% CP); 3) a corn-mixed meal diet (MM, 12.5% CP). The mixed meal is composed of rapeseed meal, cottonseed meal and sunflower meal in a ratio of 1:1:1. The feeding experiment was terminated when the pigs reached an average BW of approximately 130 kg. The results showed that the pig growth performance (ADG, ADFI, and G: F) during the experiment period and organ index (cardiac index, liver index, spleen index, lung index, and kidney index) were not affected (P > 0.05) by mixed meal dietary treatments. And replacing corn-soybean with the mixed meal had no significant influence (P > 0.05) on carcass weight, dressing percentage, fat depth, loin depth, loin eye area and lean percentage. While the corn-mixed meal diet group had higher leaf lard in comparison with the corn-soybean meal diet group (P < 0.05). And then, the pH, L*, a*, b*, drip loss, shear force and marbling score were not influenced (P > 0.05) by mixed meal dietary treatments. Moreover, the corn-mixed meal diet treatment significantly decreased (P < 0.05) IL-6 and IL-10 contents in serum compared to the corn-soybean meal diet treatment. These results support the use of mixed meals as an alternative protein ingredient with beneficial effects on immunity capacity. In particular, the mixed meal can be used as a more economical substitute for soybean meal without detrimental effects on growth performance, carcass traits, meat quality and immunity properties of finishing pigs.