Avaliação nutricional da soja integral desativada em dietas sem e com enzima protease sobre o desempenho de suínos em crescimento e terminação

Abstract

pigs through metabolism experiment and the effect of diets with and without SID, containing or not the protease enzyme, on the performance of these animals in the growth and finishing phases, carcass characteristics, and economic viability. The metabolism test was carried out by the total collecting method, using 16 immunocastrated male pigs, in the growing phase, grouped in an entirely randomized design with two treatments (control diet and diet with 30% SID replacement), to determine metabolizability coefficients of Dry Matter (DM), Organic Matter (OC) and Crude Protein (CP), besides Digestible Energy (ED), Apparent Metabolizable Energy (AME) and Apparent Metabolizable Energy corrected for nitrogen balance (AMEn). In the performance experiment, 60 immunocastrated male pigs and 60 female pigs in the growing and finishing phases were used in a randomized block design with 15 repetitions (one animal/plot). A 2 x 2 factorial scheme was used, being diets without and with SID and without and with protease enzyme, totalizing 4 treatments. The diets were formulated to meet the nutritional requirements for each phase, establishing equal diets for immunocastrated males and females, considering the requirements of the females. The nutritional characterization of the SID and the diets was made through centesimal analysis. The performance were evaluated the daily weight gain (GPDM), daily feed consumption (CRDM), feed conversion (FC), carcass characteristics and economic viability. The economic viability was performed by determining the feed cost (R$), cost/kg of weight gain (GP), economic efficiency, gross and net revenue. The metabolizability coefficients of DM, DM and CP of SID were 83.77%, 84.43% and 89.18%, respectively. The respective values of ED, AME and AMEn were 4904±117; 4805±273 and 4656±255 kcal/kg. In performance and carcass characteristics no significant interaction was observed in all phases, and when studying the factors separately in growth phase II, final and total phases. However, in growth phase I (30 to 50 kg BW) the enzyme provided an increase in the CRDM of fed pigs, not significantly affecting the FC. When analyzing the economic feasibility, it was observed that there was no interaction of factors (P>0.05) in growth phase II (50 to 70 kg), termination (70 to 90 kg) and total period of the experiment on gross revenue, net revenue, cost per kilogram of weight gain and economic efficiency of treatments. In growth phase I (30 to 50 kg BW) there was interaction of factors for feed cost per kg of weight gain, economic efficiency and net revenue, where there was an effect of the diets with SID and without enzyme on these variables, that is, the diet with SID presented a lower cost per kilo of weight gain and higher economic efficiency index and net revenue. However, the enzyme did not negatively affect the economic viability of the diets fed to the animals.With this, it is inferred that the use of SID in diets for growing and finishing pigs provides satisfactory performance and better economic efficiency, while diets with protease enzyme when added with nutritional valorization does not increase the cost of diets for these animals.