Effects of feeding cassava bagasse to slow-growing broilers / Bagaço de mandioca na alimentação de frangos de crescimento lento

The aim was to determine the energy and nutritional value of cassava bagasse (CB) and to evaluate its use for feeding slow-growing broilers. Two experiments were conducted. In the first experiment, a digestibility assay was performed to determine the apparent metabolizable energy (AME) and apparent metabolizable energy corrected for nitrogen balance (AMEn), as well as the apparent metabolizability coefficients of dry matter, crude protein and ether extract. The CB had 88.46% dry matter (DM); 1.26% crude protein (CP); 3.86% ether extract (EE); 1.06% ash and 3565 kcal/kg of gross energy. The determined values of AME and AMEn were 2508.74 kcal/kg and 2465.30 kcal/kg, respectively. The coefficients were 69.15%; 53.59% and 84.55% for DM, CP and EE; respectively. The second experiment was performed to evaluate the performance, biometry of the digestive tract and blood parameters of slow-growing broilers fed different inclusion levels (0%, 10%, 20% and 30%) of CB. In the starter phase, the inclusion of CB negatively affected feed intake (FI), weight gain (WG), whereas feed conversion (FC) had a quadratic response, with the best estimated conversion at 10.39% of CB. Blood parameters in the starter phase were not influenced by CB inclusion. In the growing phase, the inclusion of CB negatively affected the WG, FC and final weight (FW). In the finishing phase, CB did not affect performance regardless of its inclusion, except for the final weight and carcass yield that were negatively affected. Relative to biometry, there was only an effect on the relative weight of the small intestine, which increased linearly. Glucose, triglycerides and cholesterol in the growing and finishing phases were not influenced by the CB levels. On the other hand, there was a quadratic effect for total protein with a maximum level of 4.74 g/dL at 10% inclusion in the growing phase, whereas uric acid increased as CB inclusion increased in the finishing phase. Based on the results of performance, biometry and blood parameters, CB can be added to slow-growing broilers diets in the starter phase up to 10.39%. The inclusion of CB in growing diets is not recommended, whereas it can be used up to the 30% without affecting the performance of slow-growing broilers in the finishing phase

Performance, nutrient digestibility, and intestinal histomorphometry of broilers fed diet supplemented with guava extract standardized in phenolic compounds

The objective of this study was to evaluate the effects of guava extract standardized in phenolic compounds (SGE) on broiler performance, nutrient digestibility, and intestinal histomorphometry. A total of 300 one-day-old male Cobb-500® broiler chicks were distributed in a completely randomized design with five treatments (basal diet supplemented with 120 mg vitamin E/kg and basal diet supplemented with 0, 600, 800, or 1,000 mg SGE/kg) and six replicates of ten birds each. Performance was evaluated at seven and 21 days of age; digestibility of nutrients was determined by total excreta collection from 18 to 21 days of age; and histomorphometry of the small intestine was assessed at 21 days of age. Broilers fed diets supplemented with SGE or vitamin E had higher body weight and weight gain and better feed conversion than those fed unsupplemented diet at seven days of age. At the same age, there was a quadratic effect of SGE levels on body weight and weight gain, with better weights for 715 and 716 mg SGE/kg, respectively; and a decreasing linear effect for feed conversion. At 21 days of age, body weight and weight gain increased linearly with the inclusion of SGE in diet. Digestibility of feed nutrients was not influenced by treatments. Broilers fed diet supplemented with 800 or 1,000 mg SGE/kg had greater villus height and villus:crypt ratio of the duodenum than those fed unsupplemented diet. Villus height in the jejunum of broilers fed diet supplemented with 600 mg SGE/kg was lower than that of broilers that received vitamin E. Guava extract standardized in phenolic compounds can be used in diets for broilers in the starter phase, considering that the extract increases weight gain, reduces feed conversion, and helps in the development of the intestinal mucos