Nutritional supplementation of different sources of microminerals for broilers

Diferentes fontes de microminerais em rações de frangos de corte. Orientadora: Melissa Izabel Hannas. Objetivou-se avaliar a suplementação dos microminerais (Cu, Mn, Zn, Fe e Se) em premix fornecidos na forma de proteinatos e selênio levedura e sais inorgânicos em diferentes níveis de suplementação em dietas de frangos de corte sobre desempenho, concentração mineral nos tecidos e status antioxidante nos períodos de 1 a 21 e 1 a 42 dias de idade. 2.475 pintos Cobb-500® machos de 1 dia, foram distribuídos em delineamento inteiramente casualizado com 9 tratamentos e 11 repetições, com 25 aves cada. Os tratamentos foram constituídos por: Dieta basal (DB) + Padrões da indústria brasileira em fonte inorgânica, como controle positivo (CP); DB + Padrão da indústria brasileira, com suplementação micromineral 50% em fonte inorgânica e 50% em fonte orgânica; DB + Minerais em fonte orgânica (MO) em alto nível de suplementação; DB + Minerais em fonte inorgânica (MI) em alto nível de suplementação; DB + MO em nível intermediário de suplementação; DB + MI em nível intermediário de suplementação; DB + MO em baixo nível de suplementação; DB + MI em baixo nível de suplementação e DB sem suplementação micromineral, como controle negativo (CN). Em ambas as fases, houve diferença (p0,05) do CP pelo teste de Dunnett. Para atividade da GPx aos 21 e 42 dias, e análise do status antioxidante total aos 42 dias, o tratamento CN proporcionou os piores resultados pelo teste SNK (p0,05) entre os tratamentos pelo teste SNK, e o tratamento CP-MI/MO diferiu (p0.05) from PC by Dunnett's test. For GPx activity at 21 and 42 days, and analysis of total antioxidant status at 42 days, the NC treatment provided the worst results by the SNK test (p0.05) between treatments by the SNK test, and the CP-MI/MO treatment differed (p<0.05) from the NC by the Dunnet test. As for the analysis of lipid oxidation, the PC treatment presented the lowest result, by the SNK test (p<0.05). At 21 and 42 days, there was a significant effect (p<0.05) of the CP-MI/MO treatment on the concentration of Mn, Cu and Fe in the liver, highlighting the beneficial effect of the joint use of organic and inorganic sources of microminerals. Birds submitted to the NC diet showed a lower concentration of Mn, Cu and Fe in the liver at 21 and 42 days. Micromineral supplementation promotes improvement in performance responses, antioxidant parameters and mineral concentration in tissues, demonstrating the importance of mineral supplementation to maintain bird performance. The micromineral supplementation in different sources and levels showed no difference between the treatments for the responses of the performance parameters, being possible to use the lowest supplementation level, which allows reducing the amount of microminerals in the diet of the birds. While the sources and levels of supplementation of trace minerals influence the antioxidant status in the blood, concentration of microminerals in the tissues and tissue oxidation of broilers, indicating that the relationship of trace minerals with the endogenous antioxidant mechanisms of tissues and tissue deposition of trace minerals must be better studied. Keywords: Enzymatic activity. Tissue concentration. Organic sources. Microminerals

Dual-energy X-ray absorptiometry: an effective approach for predicting broiler chicken body composition

ABSTRACT: Two trials were carried out to develop and validate linear regression equations for body composition prediction using Dual-energy X-ray absorptiometry (DEXA). In Trial 1, 300 Cobb500 male chickens raised from 1 to 42 d of age were scanned in DEXA to estimate total weight, fat mass, soft lean tissue (SLT) mass, bone mineral content (BMC), and fat percentage. DEXA estimates were compared to body ash, crude fat, SLT (sum of protein and water) and scale body weight. The dataset was split, with 70% used for prediction equations development and 30% for testing, and the 5k-fold cross-validation analysis was used to optimize the equations. The R2, mean absolute error (MAE), and root-mean-squared error (RMSE) were used as precision and accuracy indicators. A negative correlation (ρ = ˗0.27) was observed for ash content, while no correlation was observed for protein content (P > 0.05). Predictive linear equations were developed to assess broiler weight (R2 = 0.999, MAE = 25.12, RMSE = 38.99), fat mass (R2 = 0.981, MAE = 13.87, RMSE = 21.28), ash mass (R2 = 0.956, MAE = 3.98, RMSE = 5.61), SLT mass (R2 = 0.997, MAE = 35.73, RMSE = 52.45), water mass (R2 = 0.997, MAE = 29.56, RMSE = 43.94), protein mass (R2 = 0.989, MAE = 12.94, RMSE = 19.05), fat content (R2 = 0.855, MAE = 0.81, RMSE = 1.05), SLT content (R2 = 0.658, MAE = 1.01, RMSE = 1.28), and water content (R2 = 0.678, MAE = 0.99, RMSE = 1.27). All equations passed the test. In Trial 2, 395 Cobb500 male chickens were raised from 1 to 42 d of age and used for validation of prediction equations. The equations developed for weight, fat mass, ash mass, SLT mass, water mass, and protein mass were validated. In conclusion, DEXA was found to be an effective approach for measuring the body composition of broilers when using predictive equations validated in this study for estimate calibration

Selenium source and level on performance, selenium retention and biochemical responses of young broiler chicks

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