Desempenho produtivo de Frangos de corte alimentados com ração contendo aditivos e substituição parcial do milho amarelo pela sêmea de Trigo

Abstract

Este estudo teve como objetivo avaliar o efeito da substituição parcial do milho amarelo por sêmea de trigo, suplementação com enzimas exógenas e aminoácidos essenciais, sobre o desempenho zootécnico e a viabilidade económica de frangos de corte da Linhagem Ross 308. O ensaio foi conduzido em uma unidade de produção de frangos de corte situada na vila sede de Marracuene, o experimento envolveu 300 pintos de um dia, distribuídos em seis tratamentos experimentais (T1–T6) com diferentes formulações dietéticas na fase inicial (1–21 dias), seguindo-se uma dieta comercial de ração Forte Merec, até aos 35 dias. 3.035 This study aimed to evaluate the effect of partially replacing yellow corn with wheat bran, supplementation with exogenous enzymes and essential amino acids, on the zootechnical performance and economic viability of Ross 308 broiler chickens. The experiment was conducted in a broiler production unit located in the town of Marracuene. The experiment involved 300 one-day-old chicks, distributed into six treatments (T1–T6) with different dietary formulations in the initial phase (1–21 days), followed by a commercial Forte Merec feed diet until 35 days. The diets (with 22% crude protein) included: T1 – control diet; T2 – concentrate + yellow corn; T3 – concentrate + yellow corn + exogenous enzymes; T4 and T5 – concentrate + yellow corn + enzymes with the inclusion of 5% and 10% wheat bran, respectively; T6 – diet with (18% CP) supplemented with essential amino acids + exogenous enzymes. Management included ad libitum feeding, temperature control and adequate environmental conditions, maintenance of biosecurity. The parameters evaluated included average initial weight (AIW), average weight gain (AWG), average feed intake (AFI), feed conversion ratio (FCR) and economic analysis (feed cost/kg of live weight). Statistical analysis was performed using a randomized block design with Tukey's test (P <0.05). The results indicated that, up to 21 days, the parameter on weight gain showed no significant difference, and the parameter on feed conversion ratio also showed no significant difference from the control, evidencing the positive effect of exogenous enzymes, equal to that of the control group. Treatments T4 and T5 also showed similar performance to the control, without significant difference, but presented a relevant reduction in production cost. Treatment T2 stood out between 22 and 35 days, achieving the best zootechnical performance and greater economic efficiency (29.06% reduction in cost/kg live weight). Treatment T6 registered lower productive performance, despite the lower feed cost, indicating limitations of protein restriction supplemented with amino acids and enzymes. Economic analysis demonstrated that all alternative diets reduced the cost of production in relation to control, with T2 being the most advantageous option. The inclusion of wheat bran with enzymes (T4 and T5) represented a promising alternative, with acceptable performance and economic gains, taking advantage of an abundant and economical byproduct in Mozambique. Protein restriction (reduction to 18% CP (T6)) proved to be the diet with the least nitrogen excretion into the environment, but compromised productive efficiency. It is concluded that nutritional strategies based on the use of local ingredients and enzymatic supplements can improve the sustainability and profitability of poultry farming in Mozambique. It is recommended to adopt diets such as those of T2 and T5, which reconcile zootechnical performance and economic viability, avoiding protein restrictions without optimized formulation. (TRADUÇAO NOSSA)