ResumoO experimento foi conduzido com o objetivo de avaliar o efeito de diferentes idades de matrizes sobre a biometria de órgãos e a morfometria intestinal de pintos de corte à eclosão. Foram incubados 200 ovos provenientes de matrizes pesadas da linhagem comercial Ross 308, com as idades de 32, 40, 48, 56 e 64 semanas. À eclosão 20 pintinhos de cada idade de matriz foram pesados individualmente e sacrificados para avaliação do peso do peito, bolsa cloacal, saco da gema e intestino delgado e do comprimento do intestino delgado. O segmento do duodeno foi coletado para mensuração da altura de vilo e da profundidade de cripta. Houve efeito linear positivo da idade da matriz (p<0,05) sobre o peso vivo, peso absoluto e relativo do saco da gema, peso absoluto da bolsa cloacal e peso absoluto e relativo do peito. Para o peso absoluto, peso relativo do intestino delgado observou-se efeito quadrático da idade da matriz (p<0,05), sendo o melhor desenvolvimento do intestino em pintos provenientes de matrizes entre 40 e 50 semanas. O peso do pinto apresentou correlação positiva com o peso do saco da gema, bolsa cloacal e peito (p<0,05). Para vilo e cripta obteve-se um efeito significativo da idade das matrizes (p<0,05) sobre a profundidade das criptas, cujo comportamento foi linear decrescente e inverso à idade das matrizes enquanto a relação vilo:cripta, apresentou comportamento linear crescente (p<0,05) de acordo com a idade das matrizes. Conclui-se que a idade da matriz tem influência na biometria dos órgãos e na morfometria da mucosa do intestino delgado de pintos de corte à eclosão. Palavras-chave: Altura de vilo, peso de órgãos, frango de corte, saco da gema AbstractThe objective of the conducted experiment was the evaluation of effect of multiple age breeders on the organs biometry and the intestinal morphometry of chicks at hatching. There were incubated 200 eggs provided from Ross 308 breeders at the ages of 32, 40, 48, 56 and 64 weeks. At hatching, 20 chicks of each breeder age were individually weighted and sacrificed in order to evaluate breast, cloacal bursa, yolk sack and small intestine weight, besides the small intestine length. The duodenum portion was collected in order to measure the villus height and the crypt depth. There were a positive linear effect of the breeder age (p<0,05) on the live weight, absolute and relative yolk sack weight, cloacal bursa

Birds fed with vegetable diets rely on the endogenous synthesis of creatine, which requires amino acids, some of which, for example arginine (Arg), are considered essential for several physiological and metabolic functions. Creatine is limited to high energy expenditure cells, particularly muscle cells. The objective of this study was to evaluate the inclusion of guanidinoacetic acid and arginine (as precursors of creatine) in vegetable diets, on the performance, quality, and yield of broiler chickens. The treatments consisted of diets based on corn and soybean meal (T1); corn, soybean meal + 3% meat meal (T2); corn, soybean meal + 0.08% guanidinoacetic acid (T3); and corn, soybean meal + 0.08% L-arginine (T4). The productive performance of the birds aged 7-, 21-, and 42-days-old was determined. Eighteen 7-day-old birds were sacrificed per treatment to evaluate breast and leg yield, and breast muscle fibers, and eighteen 42-day-old birds were sampled per treatment to determine serum uric acid, urea, creatine, lactate, and glucose concentrations. The same birds were slaughtered to calculate carcass yield in relation to live weight and commercial cut yield. The right pectoralis major muscle of each bird was used to test pH, color (luminosity L*, red index a*, and yellow index b*), and loss of water by pressure analysis, and the left side was used to analyze losses by defrosting and cooking. The data were analyzed using the software SAS. Diets to which meat or vegetable meal plus guanidinoacetic acid or L-Arginine were added resulted in higher live weight and breast meat percentage at 7 days old. Feed conversion was affected for a total period of 1 to 42 days of age (P < 0.0002). The birds with a diet supplemented with vegetable and meat meal had better feed conversion when compared to the birds that were fed with other diets. Treatments did not affect carcass and commercial cut yields, percent loss by cooking, pressure and defrosting of the broiler breast meat, or color (L, a*, and b*) and pH values. Key words: Weight gain. Glycine. ATP re-synthesis. ResumoAves alimentadas com dietas vegetais dependem da síntese endógena de creatina, que requer a participação de aminoácidos, alguns deles considerados essenciais para diversas funções fisiológicas e metabólicas, como a arginina (Arg). A creatina limita-se a células de alto gasto energético, em particular as células musculares. O objetivo foi avaliar a inclusão do ácido guanidinoacético e de arginina como precursor da creatina em dietas vegetais sobre o desempenho, a qualidade e o rendimento de carcaça de frangos de corte. Os tratamentos consistiram em dietas baseadas em milho e farelo de soja (T1); dieta a base de milho, farelo de soja + 3% de farinha de carne (T2); dieta a base de milho e farelo de soja +0,08% de ácido guanidinoacético (T3) e dieta a base de milho e farelo de soja +0,08% de L-arginina (T4). O desempenho produtivo das aves foi determinado aos 7, 21 e 42 dias de idade. Aos sete dias de idade, 18 aves/tratamento foram sacrificadas para avalia...

The objective of this study was to evaluate the effect of increasing levels of feed restriction in broilers aged from 35 to 42 days, on the performance, carcass parameters and intensity of lesions at slaughter. A total of 1,225 one-day old chicks were obtained from a commercial hatchery and were grown over a 34-days period (five weeks). At 34 days of age all birds were weighed and redistributed into a completely randomized design to perform the following treatments: control (0% feed restriction), 10, 20, 30 or 40% feed restriction. The amount of feed given to animals was adjusted daily according to the previous day's intake of the control treatment. At 42 days, birds were weighed and two birds per pen were slaughtered, one to evaluate carcass yield and cuts and the other for body composition analysis. Weight gain and feed intake were decreased linearly (p<0.05) according to increasing levels of restriction, while the feed:gain ratio showed a quadratic effect (p<0.05). The hot eviscerated carcass weight decreased linearly (p<0.05) according to increasing levels of restriction, without effects on the carcass, breast and thigh yield. The dry matter and fat of the carcass decreased and the crude protein increased (p<0.05), according to levels of restriction. We conclude that feed restriction of 2.5% in the last week of life can improve the feed efficiency of poultry, when there is a higher accumulation of fat in the carcass.