(Received: January 13, 2015; accepted: June 12, 2015) doi: 10.17533/udea.rccp.v28n4a01 Summary Background: flavophospholipol is an antibiotic growth promoter (AGP). The current ban of AGP in some countries is controversial because their benefits on the environment and economy by saving feed and reducing nitrogen excretion have been overlooked. White button mushrooms have important nutritional properties and the industry discards large quantities of waste that could be fed to animals. Objective: to evaluate the effect of dietary inclusion of five levels of edible mushroom powder (EMP) and flavophospholipol on the performance and blood serum metabolites of broilers. Methods: a total of 300 one-day-old male broiler chicks were randomly distributed into 10 treatments with three replicates of 10 chicks per pen. The experiment consisted of a factorial arrangement (2x5 treatments) with five inclusion levels of EMP supplementation (0, 0.5, 1.0, 1.5, and 2.0 g/kg of diet) and the addition of 0 or 5 mg/kg of flavophospholipol. Results: supplementation with EMP and flavophospholipol, as individual factors, had a negative effect on feed intake, but positively affected broiler weight gains and feed conversion ratio. Antibiotic supplementation increased uric acid concentration and, as an interaction with mushroom powder, reduced serum triglycerides, and very low density lipoprotein cholesterol (VLDL). The EMP also affected serum concentration of total cholesterol. Conclusion: the two substances studied, but not their combination, had a positive effect on growth performance of chickens that could be translated into economic benefits.

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RESUMENTras demostrar efectos beneficiosos sobre el desarrollo del crecimiento de pollos, se realizó un estudio para evaluar el efecto de la adición de flavofosfolipol y harina de champiñón común desde el nacimiento y durante todo el período de crecimiento sobre las características de la canal, peso de vísceras y medidas del tracto digestivo en pollos de engorda. Se utilizaron 300 pollitos machos de un día de edad distribuidos al azar en 10 tratamientos con tres repeticiones por tratamiento y 10 pollitos por corral. El experimento consistió en un arreglo factorial de 2 x 5: cinco concentraciones de harina de champiñón (0, 0.5, 1.0, 1.5 y 2.0 g/kg de dieta) y la adición de dos concentraciones de flavofosfolipol (0.0 o 5.0 mg/kg), desde el nacimiento hasta el sacrificio a los 42 días de edad. Los resultados demostraron que la adición de harina de champiñón y flavofosfolipol tienen un efecto positivo sobre el peso de partes de la canal de importancia comercial como el pecho y muslos. En cambio, no hubo ningún efecto sobre el peso de las alas. En relación al peso de las vísceras, la harina de champiñón (pero no el flavofosfolipol o la interacción de ambos), afectó el peso del timo, bazo, bolsa de Fabricio e hígado. Finalmente, a pesar de escasos resultados significativos en varias medidas del tracto digestivo, no se encontró ningún efecto estadístico de la harina de champiñón o la adición del antibiótico en estas variables. PALABRAS CLAVE: Pollos, Canal, Flavofosfolipol, Agaricus bisporus, Tracto digestivo. ABSTRACTAfter showed its beneficial effects on chicken growth performance, a study was conducted to evaluate the effect of adding from birth and during the whole growth period, flavophospholipol and edible mushrooms powder on carcass characteristics, viscera weights and digestive tract measurements of male broiler chicken. A total of 300 one-dayold male broiler chicks were randomly distributed into 1 to 10 treatments with three replicates per treatment and 10 chicks per pen. The experiment consisted in a 2 x 5 factorial arrangement of treatments including five concentrations of mushrooms powder (0, 0.5, 1.0, 1.5 and 2.0 g/kg of diet) and the addition of 0.0 or 5.0 mg/kg of flavophospholipol from birth date to slaughter time at 42-d. Results show that the additions of dietary mushroom powder and flavophospholipol have a positive effect on weights of carcass parts with commercial importance as the breast and drumsticks. In contrast, there is no effect on wings weight. Regarding viscera weights, mushroom powder but not flavophospholipol or the interaction of both, affected the thymus, spleen, bursa of Fabricius and liver weights. Finally, despite weak statistically significant results on several measurements of the digestive tract, results show no effect of mushroom powder or the antibiotic addition on these variables.

Contents Age negatively affects reproductive success of broiler breeder flocks. One of the main hormones involved in the change of fertility with the age is testosterone (TT). The introduction of young males at later production stages of broiler flocks is known as spiking and is expected to reduce the fertility decline with age. The aim of this study was to determine the effect of injection of different levels of TT and the effect of spiking on reproductive fitness of broiler breeder flocks. Two experiments were conducted on Ross 308 breeder flocks for 10 weeks (41–50 weeks of age). The experiment 1 included a control and three treatments corresponding to three doses of TT (0.1, 0.2 and 0.3 cc), while the experiment 2 included a control and one treatment corresponding to spiking. The lower dose of TT (0.1 cc) and the spiking clearly slowed down the decline in hatchability. Therefore, either the external administration of TT to the males when the natural concentration of TT starts to decline or spiking the breeder flock with young roosters could contribute to improve reproductive success in later stages of the production cycle in broiler breeder flocks.