Efeito de diferentes níveis de inclus o de farelo de arroz em dietas suplementadas com fitase para frangos de corte = Effect of different inclusion levels of rice bran in diets supplemented with phytase for broiler chickens

O experimento foi realizado com o objetivo de avaliar o desempenhozootécnico, rendimento de carca a e a deposi o de fósforo e cinzas na tíbia de frangos de corte submetidos a dietas contendo quantidades crescentes de farelo de arroz integral (FAI), suplementados com fitase. Foram utilizados 600 frangos de corte, machos, da linhagemRoss, alojados em boxes de acordo com um delineamento inteiramente casualizado, nos seguintes tratamentos: T1-ra o referência (milho e farelo de soja); T2-ra o referência com 750 FTU g-1; T3-ra o com 3,5% de FAI com 750 FTU g-1; T4-ra o com 7,5% de FAI com 750 FTU g-1; T5-ra o com 10,5% FAI com 750 FTU g-1 e T6-ra o com 14% FAIcom 750 FTU g-1. A inclus o de fitase, com a utiliza o de FAI até o nível de 14% e redu o do fósforo inorganico na formula o da ra o, n o afetou o desempenho zootécnico e características de carca a dos frangos de corte, porém reduziu a deposi o de fósforo e cinzas na tíbia dos ossos. The experiment was carried with the objective of evaluating the productive performance, carcass yield, phosphorus availability and tibia ash in broilers subjected to diets containing increasing amounts of whole rice bran (WRB), supplemented with phytase. Six hundred broilers (Ross), all males, were allocated in boxesaccording to a completely randomized design, being fed the following regimens: T1) standard feed (corn and soybean meal); T2 standard feed with 750 FTU g-1; T3) feed with 3.5% of WRB with 750 FTU g-1; T4) feed with 7.5% of WRB with 750 FTU g-1 T5) feed with 10.5% WRB with 750 FTU g-1 and T6) feed with 14% WRB with 750 FTU g-1. The inclusion of phytase with the use of WRB to the level of 14% and the reduction of the inorganic P in the formulation of the feed did not affect the performance and carcass characteristics of the broiler chickens; however, it did decrease the presence of phosphorus and ash in the tibia.