Nutritional evaluation of deactivated soybean and its use in diets with and without protease enzyme on the performance of growing and finishing pigs

Abstract

Objetivou-se avaliar o valor nutricional da soja integral desativada (SID) para suínos através do ensaio de metabolismo e o efeito de dietas com e sem SID contendo ou não a enzima protease sobre o desempenho destes animais nas fases de crescimento e terminação, características de carcaça e a viabilidade econômica. O ensaio de metabolismo foi realizado pelo método de coleta total, utilizando 16 suínos machos imunocastrados, na fase de crescimento, agrupados em um delineamento inteiramente casualizado com dois tratamentos (dieta controle e dieta com substituição de 30% da SID), para determinar coeficientes de metabolizabilidade da Matéria Seca (MS), Matéria Orgânica (MO) e Proteína Bruta (PB), além da Energia Digestível (ED), Energia Metabolizável Aparente (EMA) e Energia Metabolizável Aparente corrigida para o balanço de nitrogênio (EMAn). No experimento de desempenho foram utilizados 60 suínos machos imunocastrados e 60 suínos fêmeas nas fases de crescimento e terminação, em um delineamento em blocos casualizados com 15 repetições (um animal/parcela). Foi utilizado um esquema fatorial 2 x 2, sendo dietas sem e com SID e sem e com enzima protease, totalizando 4 tratamentos. As dietas foram formuladas para atender as exigências nutricionais para cada fase, estabelecendo dietas iguais para machos imunocastrados e fêmeas, considerando a exigência das fêmeas. Foi feita a caracterização nutricional da SID e das dietas, através de análise centesimal. Os resultados foram considerados estatisticamente significativos em um nível de P0,05) nas fases de crescimento II (50 a 70 kg), terminação (70 a 90 kg) e no período total do experimento sobre a receita bruta, receita líquida, custo por quilo de ganho de peso e eficiência econômica dos tratamentos. Porém, na fase de crescimento I (30 a 50 kg de PV) houve interação dos fatores para custo de ração por quilo de ganho de peso, eficiência econômica e receita líquida, onde houve efeito das dietas com SID e sem enzima sobre estas variáveis, ou seja, a dieta com SID apresentou um menor custo por quilo de ganho de peso e maior índice de eficiência econômica e receita líquida. Entretanto, a enzima não afetou negativamente a viabilidade econômica das dietas fornecidas aos animais. Com isso, infere-se que a utilização de SID em dietas para suínos em crescimento e terminação proporciona um desempenho satisfatório e melhor eficiência econômica, enquanto as dietas com enzima protease quando adicionada com valorização nutricional não aumenta o custo das dietas destes animais.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.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPE