Crude glycerin reduces electricity consumption and improves pellet quality of broiler feed.

Two experiments were carried out to determine the metabolizable energy of crude glycerin (CG) and to evaluate the effect of adding different levels of CG on broiler performance and yield of carcass and cuts. The first consisted of a metabolism assay using total excreta sampling method aiming to determine the apparent metabolizable energy corrected for nitrogen balance (AMEN). This assay was performed in two phases: 10–18 days (initial phase) and 25–33 days of age (growth phase). The broilers were alloted in a randomized design with two treatments (reference diet and reference diet + 80 g/kg of CG inclusion) and nine replications, with ten birds per cage. The AMEN was 2651 kcal/kg and 3013 kcal/kg, for the initial and growth phases, respectively. In the second experiment, 1600 Cobb 500 male broilers from 1 to 42 days were alloted in a randomized block experimental design, with 8 treatments and 8 replications of 25 birds per experimental unit, according to factorial arrangement (2 feed forms × 4 levels of CG: 0, 40, 80 and 120 g/kg). At 43 days of age, three birds from each cage were slaughtered to evaluate yield of carcass and cuts in each treatment. There was a quadratic effect (P < 0.01) on feed intake and weight gain of glycerin fed birds, but no difference in feed conversion (P>0.05). Carcass and cut weights presented quadratic behavior (P < 0.01), but regarding yield, only quadratic effect (P < 0.01) was observed for carcass, linear increase (P < 0.01) for wings and linear reduction (P < 0.01) for fat. Using CG improved weight gain. Up to 46.30 g/kg CG improved carcass yield and up to 120 g/kg reduced fat deposition.