RESUMO Objetivou-se avaliar o processamento térmico de rações pré-iniciais sobre o desempenho, morfometria dos órgãos do sistema digestório e metabolizabilidade dos nutrientes das rações de pintos de corte. Foram utilizados 180 pintos de corte, distribuídos em delineamento inteiramente casualizado, com dois tratamentos, seis repetições de 15 aves cada. Os tratamentos consistiram em ração peletizada (70°C) e ração extrusada (150°C). O ensaio de metabolizabilidade foi realizado de quatro a sete dias de idade, enquanto o desempenho e morfometria dos órgãos do sistema digestório foram avaliados aos sete e 21 dias de idade. Os dados foram submetidos à análise de variância. Aos sete dias de idade, os pintos que consumiram ração extrusada apresentaram menor consumo de ração, menor desenvolvimento dos órgãos do trato digestório, pior metabolizabilidade do nitrogênio, matéria seca, além de menor energia metabolizável em relação a ração peletizada. Do mesmo modo, aos 21 dias de idade, os pintos que consumiram ração pré-inicial extrusada apresentaram pior desempenho em relação a ração peletizada. Conclui-se que ração extrusada a 150°C para pintos de corte na fase pré-inicial, resulta em menor metabolizabilidade dos nutrientes e menor desenvolvimento dos órgãos do sistema digestório aos sete dias de idade e pior desempenho aos 21 dias.

ABSTRACT The objective of this study was to evaluate the thermal processing of pre-initial diets on performance, morphometry of the organs of the digestive system and nutrient digestibility in broiler chicks. The test sample consisted of 180 broiler chicks distributed in a completely randomized design, with two treatments, six replications of 15 birds each. The treatments consisted of pelleted feed (70°C) and extruded feed (150°C). The metabolism test was realized from 4 to 7 days of age, while the performance and morphometry of the organs of the digestive system were evaluated at 7 and 21 days of age. The data were submitted to analysis of variance. At seven days of age, chicks that consumed extruded feed had lower feed intake, less development of digestive tract organs, lower nitrogen absorption rate, dry matter, in addition to less metabolizable energy compared to pelleted feed. Likewise, at 21 days of age, chicks that consumed extruded pre-starter feed performed worse than pelleted feed. The conclusion is thus reached that feed extruded at 150 ° C for broiler chicks in the pre-initial phase, results in lower nutrient digestibility and an inferior development of the organs of the digestive system at 7 days of age and worse performance at 21 days.

The objective of this experiment was to evaluate the effect of two digestible lysine levels and four digestible arginine levels on laying hens from 24 to 48 weeks of age. Three hundred and twenty Lohmann LSL laying hens were allotted in a completely randomized design in a 2 × 4 factorial arrangement, with two levels of digestible lysine (700 and 900 mg/kg of diet) and four digestible arginine levels (700, 800, 900 and 1000 mg/kg of diet). Results indicated requirement of 884 and 830 mg of digestible arginine/kg of diet, considering an average feed intake of 95 g/hen/day and an average hen weight of 1.5 kg, aiming at lesser feed intake and better nutritional balance of nitrogen, respectively. High digestible lysine levels in the diet require higher digestible arginine supplementation for a better performance of hens.