Broilers fed with diets formulated with different levels of avP, Ca and Na and increasing doses of phytase have shown no change on performance, quantitative carcass characteristics, ash and phosphorus deposition in tibia and weight of organs.

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 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.

To examine the association between phytase and xylanase in diets with nutritional adjustments on the metabolizability of feed by broiler diets, 250 chickens were used and distributed among five treatments and five replicates of 10 broilers each. The treatments were: positive control diet - without phytase or xylanase; negative control diet - with an energy reduction of 0.419 MJ/kg, without phytase or xylanase; and three diets containing xylanase and phytase and energy reductions of 0.209, 0.409 and 0.628 MJ/kg. For all energy-reduced diets, the nutritional matrix of phytase with phosphorus (0.15%), calcium (0.165%) and sodium (0.035%) was considered. The energy reduction of 0.628 MJ/kg with inclusion of the enzymes resulted in a higher metabolizability of the crude protein, also the apparent and apparent corrected metabolizable energy coefficients for nitrogen balance were higher in diets with a reduction energy of 0.209 MJ/kg, however had values similar to those obtained in the positive control diets and diets with energy reduction of 0.628 MJ/kg containing enzymes. The inclusion of phytase (500 FTU/kg) and xylanase (16,000 BXU/kg) in broiler diets, makes it possible to reduce metabolizable energy by up to 0.628 MJ/kg, available phosphorus, calcium, and sodium, and improve the metabolizability of the nutrients.