Coeficientes energéticos de alimentos de origem vegetal determinados com frangos de corte em diferentes idades

In order to determine the apparent metabolizable energy (AME), the AME corrected for nitrogen balance (AMEn), the apparent coefficients of metabolization (ACM) of gross energy and the ACM corrected for nitrogen balance (ACMn), an experiment was conducted to evaluate five different plant foods (corn, soybean meal, deactivated full-fat soybean, wheat bran and soybean oil) for broilers at different ages (1-8, 11-18, 21-28, 31-38 and 41-48 days). The method of total excreta collection was used, divided into five metabolism assays. The birds were housed in metabolic cages in a completely randomized design, with five treatments and five replicates per treatment, totaling 25 experimental units. The AME and AMEn values increased with the age of the birds for most foods, except soybean meal. The smaller AMC and AMCn of gross energy were obtained for wheat bran. There was adjustment of the equation to the linear response plateau model for the ACM of corn, soybean meal and deactivated full-fat soybean. The wheat bran and soybean oil were adjusted to the linear regression model. The equations show that the digestibility of energy tends to increase with age, except for soybean meal, which had higher metabolization with younger birds. We conclude that the age of the birds influences the determination of the metabolizable energy of feed.O objetivo deste trabalho foi determinar os valores de energia metabolizável aparente (EMA), os valores de EMA corrigida para o balanço de nitrogênio (EMAn), os coeficientes de metabolizabilidade aparente (CMA) da energia bruta e os CMA corrigidos para o balanço de nitrogênio (CMAn) de cinco diferentes alimentos de origem vegetal (milho, farelo de soja, soja integral desativada, farelo de trigo e óleo de soja) com frangos de corte em diferentes idades (1 a 8, 11 a 18, 21 a 28, 31 a 38 e 41 a 48 dias). Foi utilizado o método de coleta total de excretas. Os frangos foram distribuídos em um delineamento inteiramente casualizado, com cinco tratamentos e cinco repetições cada, totalizando 25 unidades experimentais. Os valores de EMA e EMAn aumentaram com a idade das aves para a maioria dos alimentos, exceto para o farelo de soja. O menor CMA e CMAn da energia bruta foi obtido com o farelo de trigo. Houve ajuste das equações ao modelo LRP para o CMA do milho, farelo de soja e soja integral desativada. O farelo de trigo e o óleo de soja se ajustaram ao modelo de regressão linear. As equações demonstram que a metabolizabilidade da energia tende a aumentar com a idade, com exceção do farelo de soja, que teve maior metabolizabilidade com aves mais jovens. Conclui-se que a idade das aves influencia na determinação dos valores de energia metabolizável dos alimentos

Levels of metabolizable energy and digestible lysine for broiler chicks 8-21 days of age

The experiment was conducted with the objective of evaluating the effect of metabolizable energy (ME) levels and digestible lysine (DL) levels on the performance of 8-21 days old broiler chicks. Eight hundred and sixty four broiler chicks were used, with average weight of 160 ± 5g, randomly distributed in 48 boxes (experimental unit), experimental unit in a factorial 4x4 with four levels of ME (2,700, 2,825, 2,950, and 3,075 kcal kg-1) and four levels of DL (1,080; 1,187; 1,295 and 1,403%) resulting in 16 treatments with three replications. Increases in levels of ME and DL in the diets caused significant interaction (P &lt;0.05) in weight gain and feed conversion. Increasing levels of ME and DL caused significant interaction (P &lt;0.05) for the deposition rate of protein and fat in the carcass. The simultaneous increases of ME and DL in the diet promoted a linear increase (P &lt;0.05) in villus height of the duodenum, jejunum, and villous:crypt ileum. It is recommended the use of 3,075 kcal kg-1 ME and 1,403% of LD for best performance, protein deposition rate, and intestinal morphometric characteristics of 8-21 days old broiler chicks.</p

Performance of broiler chickens at pre starter and starter phases using diets with different metabolizable energy values of ingredients, at different ages

ABSTRACT: The experiment was carried out to evaluate the performance of broilers in 1-7 and 8-21 days of age, using metabolizable energy values of corn, soybean meal and soybean oil previously determined for each phase in another metabolism trial. Two trails were conducted, divided into phases according to ages: pre-starter (1-7 days) and starter (8-21 days). At each trial were used 924 broiler chicken randomly distributed into 42 experimental units in a completely randomized design with six treatments and seven replications. Treatments consisted of five diets using the values of apparent metabolizable energy corrected for nitrogen balance of corn, soybean meal and soybean oil determined in different metabolism trials, and one diet with the metabolizable energy values of these same ingredients, published on the literature. At the end of each stage, the animals and feed leftover were weighted to determine feed intake, weight gain and feed conversion ratio. Diets with higher soybean oil inclusion, showed superior performance at different stages. At pre-starter only feed conversion ratio was significant (P<0.05). In the initial phase, there was a significant difference (P<0.05) for feed conversion ratio, daily and average weight gain