The performance of Arbor Acres broiler breeders (1,296 females; 144 roosters) was evaluated when submitted to the following treatments (T): T1 = feeding at 6:30 a.m. (control); T2 = 50% feeding at 6:30 a.m. and 50% at 3:30 p.m. (dual feeding); T3 = feeding at 11:00 a.m.; and T4 = feeding at 3:30 p.m. Treatments were randomly distributed in 48 pens. There were 27 females and 3 males in each pen and 12 repetitions per treatment. Nutrition and management were as recommended for the commercial strain. It was evaluated age at first egg (AFE), total egg production (TEP), number of days with production above 80% (DAP80), laying peak (P), female mortality (MOR), and gross profit margin (GM) per hen. Data were submitted to analysis of variance and means were compared by Students t-Test. TEP of T1 (186.3±2.3) and T2 (186.5±1.5) were higher (p<0.05) than that of other treatments. TEP of T3 (177.2±2) was the smallest (p<0.05), probably due to the less significant values of DAP80 (18.9±6.0 days) and P (81.36±0.95%). AFE was earlier (p<0.05) in T2 birds. Mortality was similar (p>0.10) among treatments. GM per hen was better (p<0.05) in T1 and T2 hens. Control and dual treatments were more efficient than other treatments. It was concluded that it is possible to change conventional feeding managements by the dual feeding system.

A formulação com base no conceito de proteína ideal (PI) é mais eficiente quando são usados ingredientes alternativos ao milho (M) e ao farelo de soja (FS). Assim, o objetivo desse trabalho foi comparar formulações de dietas utilizando o conceito de PI, usando farinha de vísceras (FV) em substituição ao FS, em dietas de frangos de corte. Os tratamentos foram os seguintes: T1 = dieta com 22 % e 20% de proteína bruta (PB) nas fases inicial (FI) e de crescimento (FC) e 3200 kcal/kg de EM durante todo experimento; T2 = energia semelhante a dieta T1 e PI à base de M e FS (1,15% de lisina digestível na FI e 0,90% de lisina digestível na FC; T3=dieta semelhante a T2, com 20 % e 25 % de substituição do FS por FV nas FI e FC, respectivamente; T4=dieta semelhante a T3, com 40 e 50 % de substituição do FS por FV, nas FI e FC, respectivamente; T5=dieta semelhante a T4, porém com balanço por aminoácidos (AA) totais (1,10 e 1,00 % de lisina total nas FI e FC, respectivamente). Os resultados permitiram concluir que a formulação com base na PI é melhor do que aquela que considera a PB ou AA totais. A inclusão de 20 % FV na FI e 25 % na FC de frangos de corte, em substituição ao FS, melhorou o desempenho até os 21 dias e não alterou o desempenho até os 42 dias em dietas formuladas dentro do conceito de proteína ideal.

One thousand two hundred and ninety six Arbor Acres females and 144 males were used to study the influence of feeding time on sexual maturity and carcass composition. Treatments were: T1 = feeding at 6:30 am, T2 = 50% feeding at 6:30 am and 50% at 3:30 pm (dual), T3 = feeding at 11:00 am, T4 = feeding at 3:30 pm. Nutrition and management were as recommended to the commercial line. Variables studied were: sexual maturity at 5% production (SM), mean egg production percentage (PEP) body weight (BW), carcass composition, tibia weight (TIBW) and tibia calcium (Ca) and phosphorus (P) contents. Analysis of variance was used, and the means were compared using Student's t test. T2 females reached SM at 25.92 weeks, which was earlier (p<0.01) than the other treatments. PEP was greater (p<0.01) for T1 and T2 than for the other treatments. BW was greater in T1 and smaller in T4 (p<0.05) than in the other treatments. TIBW was greater in T3 than in T1 and T2 (p<0.05), with no effect (p>0.10) on carcass dry matter (DM), ether extract (EE), crude protein (CP) and ash (ASH). DM, EE, TIBW, Ca and P increased (p<0.05) whereas CP and ASH decreased with age. Time of feeding influenced body weight, but not carcass composition. Hens fed twice a day had earlier sexual maturity and similar egg production compared to those fed once at 6:30 am