The present study proposes to examine the effect of dietary levels of metabolizable energy, under a fixed nutrient:calorie ratio, on the production performance; body fat and protein deposition; and carcass characteristics of free-range broilers from 1 to 84 days of age. Nine hundred unsexed chicks were allocated to six treatments in a completely randomized design with six replicates of 25 birds each. Treatments consisted of diets with varying levels of metabolizable energy (2700, 2800, 2900, 3000, 3100 and 3200 Kcal ME/kg of diet) and a fixed proportion of nutrients relative to the energy level according to the nutritional requirements for each rearing phase. Body weight, weight gain, feed intake, feed conversion, production viability, metabolizable energy intake, protein intake, lysine intake, body fat deposition, body protein deposition and carcass characteristics were evaluated. Data were subjected to analysis of variance and, later, to regression analysis. Increasing levels of metabolizable energy, coupled with a fixed nutrient:calorie ratio, reduced feed intake, increased body weight and weight gain, improved feed conversion and did not affect carcass characteristics. In conclusion, adjusting the nutrient supply according to the dietary energy level improves production performance by improving feed conversion, ensuring adequate nutrient intake and preserving fat and protein deposition in the carcass when the metabolizable energy level is raised up to 3200 Kcal/kg in all rearing stages.

The aim of this study was to evaluate the effect of dietary metabolizable energy levels on the performance and carcass yield of free-range broiler chickens from 1 to 84 days of age. A total of 900 male day-old naked neck lineage chicks were distributed in a completely randomized design between six levels of metabolizable energy (2,700; 2,800; 2,900; 3,000; 3,100 and 3,200 kcal.kg-1 diet) with six replications of 25 birds each. The increase in levels of dietary metabolizable energy resulted in a linear reduction of the feed intake, crude protein and digestible lysine intakes, as well as in the protein body deposition and protein efficiency and linear improvements in the feed conversion ratio of chickens in all experimental phases. The carcass yield, wing and abdominal fat weight and percentage of abdominal fat reduced linearly by increasing the level of dietary metabolizable energy. The diet including 2700 kcal.kg-1 of metabolizable energy in the diet of free-range broiler chickens in phases 1 to 28, 28 and 56 and 57 to 84 days of age does not interfere in the broilers performance and results in a better carcass yield in the final period of production.

This study aimed to determine nutrient metabolizability coefficients and apparent metabolizable energy (AME) and nitrogen-corrected AME (AMEn) values of moringa leaf meal and bocaiuva pulp for slow-growing broilers. Three hundred and fifty 1-day-old chicks of the Red Naked Neck line were allocated to five treatments in a completely randomized design with seven replicates of 10 birds. Treatments consisted of a control diet and four test diets. The proportion of ingredients evaluated in the test diets was 20% moringa leaf meal and bocaiuva pulp and 40% corn and soybean meal. The total excreta collection method was applied with 1% ferric oxide included in the diets as a marker of start and end of collection, in the starter, grower and finisher phases. The metabolizability coefficients of dry matter, crude protein and ether extract and the AME and AMEn values of moringa leaf meal, bocaiuva pulp, corn and soybean meal were determined. Data were subjected to analysis of variance and means were compared by Tukey’s test at the 5% probability level. The protein from moringa leaf meal and the fat from bocaiuva pulp are highly metabolizable by birds at different ages. The AME and AMEn values of moringa leaf meal ranged from 2557 to 2868 Kcal/kg and 2205 to 2479 Kcal/kg, respectively. In bocaiuva pulp, AME and AMen ranged between 2680 and 3119 Kcal/kg and 2483 and 2490 Kcal/kg, respectively. Therefore, the alternative ingredients can be used in the formulation of diets for slow-growing broilers to partially replace corn and soybean meal.

This study aimed to evaluate the introduction of cassava flour, moringa leaf meal and bocaiuva pulp in laying hens’ diets on egg quality. Nine hundred eggs from Dekalb® White laying hens between 34 and 54 weeks of age rearing in semi-intensive system were used in the experiment. The laying hens were submitted to the following diets: 1 - diet control: maize and soybean meal base diet; 2 - diet with inclusion of 18% of cassava root meal+4% moringa leaf meal+4% of bocaiuva pulp; 3 - diet with the inclusion of 24% of cassava root meal+6% of moringa leaf meal+6% of bocaiuva pulp; 4 - diet with the inclusion of 30% of cassava root meal+8% of moringa leaf meal+8% bocaiuva pulp. The inclusion of higher levels of alternative ingredients intensified yolk color; it improved the percentage of albumen, yolk index, specific gravity and reduced yolk percentage. The association of 30% de cassava root meal+8% de moringa leaf meal+8% de bocaiuva pulp does not decrease the egg quality; it gives the yolk an orange yellow tone and it can be used in diets of laying hens with 34 and 54 weeks of age in semi-intensive systems.