Torta de girassol associada a enzimas na alimentação de frangas de reposição de diferentes linhagens

Abstract

The objective of this study was to evaluate the inclusion of sunflower cake (SC) and its metabolization with or without the addition of enzymes in the rations of light and medium weight replacement pullets during growth periods and their effects on performance, economic viability, sexual maturity and quality of eggs at the beginning of the laying phase. In the experiment I, with light pullets, performance evaluation and two metabolism tests were performed. For the performance, 540 pullets were used (7 to 17 weeks of age) in a completely randomized design in a 2 x 2 + 1 factorial scheme (two inclusion levels of SC, 10% and 20%), two forms of the enzyme complex, absence), plus a control treatment, with 6 replicates of 18 birds. Between the 9th and 10th week of the birds, the first metabolism test was performed and the second between the 14th and 15th week, using the same treatments with 6 replicates of 5 birds. As for the performance in the growth period, no significant interaction (P> 0.05) was observed between SC and enzyme levels. Rations and enzymes alone significantly influenced (P <0.05) feed intake and conversion to feed. It was observed a reduction of the coefficients of metabolization of dry matter (CMDM), nitrogen (CMN), crude energy (CMCE), apparent metabolizable energy (AME) and corrected apparent metabolizable energy for the nitrogen balance (AMEn) as SC levels were increased, even with the presence of enzymes and significant interaction (P <0.05) between the levels of SC and enzymes for CMDM. At the end of the growth period, 360 birds were transferred to the laying shed and remained there until the 35th week of age, maintaining the same experimental design. The rations did not affect the productive performance, sexual maturity and egg quality, only the values of specific density decreased in relation to the control and significant interaction (P <0.05) for the same variable. In the experiment II the same evaluations were performed with 480 medium weight pullets in the growth period, with the same factorial scheme of the light birds (2 x 2 +1), but the inclusions of SC were 12% and 24% with 6 replicates of 16 birds for performance. The two metabolism essays were performed in the same period of experiment I. The replicates were of 4 birds and at the end of the 35th week of age, 330 birds were transferred to the laying shed. In the growth phase, no significant interaction (P> 0.05) was observed between the levels of SC and enzymes, in which rations and enzymes influenced dietary intake and feed conversion alone (P <0.05). However, the rations did not affect the productive performance, sexual maturity and quality of the eggs, occurring only reduction of the values of specific density in relation to the control treatment. In the metabolisms, a reduction of Coefficients of Metabolization (CM) was observed as the level of SC was increased, even with the presence of enzymes. Up to 20% inclusion of SC can be used in light-weight rations and up to 24% for light-weight rations without performance impairment. The added enzymatic amount was sufficient to maintain performance. However, it did not guarantee greater metabolization of the nutrients contained in the rations. Regarding the economic viability analysis with the light birds, the rations that contained 20% SC with enzymes presented lower costs / Kg of body weight gain and better indices of efficiency and cost. With the medium weight pullets, the best results for these variables were obtained with the inclusion of 24% SC without enzymes.