Melhorando a alimentação de poedeiras: avaliação do efeito da substituição parcial da farinha de milho pela sêmea de trigo, com ou sem óleo de soja, sobre a qualidade dos ovos e indicadores de desempenho económico de poedeiras

Abstract

Despite being abundant and having a high protein content, wheat bran (WB) in the diet of monogastric animals is limited due to its high fiber content and low energy level. In the present study, the effect of replacing corn flour with wheat bran, in the absence or presence of soybean oil, on egg quality and economic performance indicators of laying hens was evaluated. In a completely randomized design, 36 ISA Brown laying hens, 30 weeks old, were used. The hens were distributed in individual cages with 3 replicates of 4 birds each, and subjected to three treatments: T1: control diet; T2: control diet with 20% of the corn flour replaced by wheat bran; and T3: control diet with 20% corn flour replaced by 17.5% wheat bran and 2.5% soybean oil. To evaluate egg quality over an 8-week period, the following parameters were measured and/or calculated: egg weight, length and width, shell strength and thickness, percentage of shell, yolk and albumin, Haugh unit and yolk color. For the economic evaluation, the following were analyzed: feed costs, production cost per egg, production cost per dozen eggs, gross revenue, gross value added, profitability index, contribution margins and break-even point. Data were subjected to analysis of variance (ANOVA) using SPSS version 25 software (IBM Corp., NY, USA). Tukey's test was used to compare treatment means, with a significance level set at 5%. Partial replacement of corn flour by wheat bran, in the absence or presence of soybean oil, showed no differences (P > 0.05) for all egg quality parameters evaluated and led to a significant reduction in gross revenue (P < 0.05), together with a notable increase (P < 0.05) in gross added value, profitability index and contribution margin. In relation to the break-even point, no significant effect was observed (P > 0.05). It was concluded that the replacement of 20% of corn flour by 17.5% of ST and 2.5% of soybean oil was as efficient as the basal diet in relation to egg quality and improved economic performance.