This work studied the effect of supplementing commercially available amino acids in low-protein diets using different ratios of digestible (dig) glycine+serine:lysine (Gly+Ser:Lys) on performance, serum parameters, feathering, and litter characteristics of broiler chickens during the starter period. A total of one thousand fifty 1-d-old Cobb-Vantress male chicks were distributed in a completely randomized experimental design into 6 treatments with 5 replicates of 35 birds each. The treatments were as follows: T1, control diet based on corn and soybean meal formulated with 22% CP (dig Gly+Ser:Lys ratio of 147); T2, diet with a 2% CP reduction, supplemented with Val (dig Gly+Ser:Lys ratio of 137); T3, similar to T2 with the addition of Gly (dig Gly+Ser:Lys ratio of 147); T4, diet with a 3% CP reduction, supplemented with Val, Ile, and Arg (dig Gly+Ser:Lys ratio of 127); and T5 and T6, similar to T4 with the addition of Gly (dig Gly+Ser:Lys ratios of 137 and 147, respectively). At 7 and 21 d, broilers that had received diets with a 3% CP reduction (19% CP) and a Gly+Ser:Lys ratio that was equivalent to 127 had lower G:F (P < 0.05) and lower total protein and albumin serum concentrations (P < 0.05) than those broilers that received the control feed. However, these parameters were restored to the same level as the control diet with an increase in the dig Gly+Ser:Lys ratio from 127 to 137 and 147. Diets with a 3% CP reduction (19% CP) resulted in litter with reduced (P < 0.05) nitrogen content and lower ammonia emission than the litter of broilers receiving the control diet. The treatments did not influence (P > 0.05) the feather length or feathering scores at 21 or 28 d of age. The supplementation of essential amino acids while maintaining dig Gly+Ser:Lys ratios at and above 137 allowed for a reduction in the dietary CP of 3% without undermining the performance, feathering or serum parameters of early stage broilers.

The objective of this study was to determine the requirements and interactions between the standardized ileal digestible (SID) Leu and Val levels in

Experimental power is a measure of the ability of an experiment to detect differences between treatment means. Researchers design experiments and the

Foram determinados os valores de energia metabolizável aparente (EMA) e energia metabolizável aparente corrigida pelo balanço de nitrogênio (EMAn) e os coeficientes de metabolizabilidade aparente (CMA) e aparente corrigida pelo balanço de nitrogênio (CMAn) de cinco alimentos. Cento e vinte pintos de corte com 21 dias de idade foram distribuídos aleatoriamente em seis tratamentos (uma ração-referência e cinco rações-teste) e quatro repetições de cinco aves. Os alimentos avaliados foram: resíduo de incubatório (RI), farinha de penas (FP), farinha de vísceras de aves (FVA) e duas farinhas de carne e ossos (FCO 1 e FCO 2). Os alimentos substituíram em 20% a ração-referência. Para determinação dos valores de EMA e EMAn, foi utilizado o método tradicional de coleta total de excretas. Os valores de EMA, expressos em kcal/kg de matéria natural (MN), para os alimentos RI, FP, FVA, FCO 1 e FCO 2, foram de 1.495, 2.774, 2.676, 2.537 e 1.652 e os de EMAn, de 1.301, 2.758, 2.384, 2.307 e 1.488, respectivamente. De acordo com os valores de EMA, EMAn e energia bruta (EB), foram calculados os CMA e o CMAn para os alimentos RI, FP, FVA, FCO 1 e FCO 2, que foram, respectivamente, de 60,09; 55,49; 69,31; 67,71 e 51,14, para o CMA, e de 52,26; 55,18; 61,75; 60,85 e 46,07, para o CMAn.

This study was to evaluate the sunflower cake and enzymatic complex fed to broilers from 22 to 42 d of age. In a completely randomized design, a total of 850 birds were allotted in a 2×5 factorial scheme (with and without enzymatic complex) and five inclusion levels (0%, 5%, 10%, 15%, 20%) of sunflower cake. There were 5 replications and 17 birds in each experimental unit. Data from performance, carcass yield and intestinal morphology were evaluated. Feed intake, weight gain, final weight and feed:gain ratio linearly worsened as sunflower cake increased. For weight gain, final weight and feed:gain ratio, the birds whose diets contained levels of 15% and 20% of sunflower cake showed worse values (p<0.05) than the birds fed the control diet. When fed the enzymatic complex, birds improved (p<0.05) crypt depth and villus:crypt ratio in the jejunum. As inclusion levels of sunflower cake increased, villus depth and villus:crypt ratio in duodenum, jejunum and ileum linearly reduced and the crypt depth linearly increased. Carcass yield linearly reduced as sunflower cake increased. Based on performance, sunflower cake can be used up to 10% in broilers feeding from 21 to 42 days of age.

The objective of this study was to evaluate the use of a vegetal source of choline as a replacement of choline chloride in the diet for broilers from one to 21 and 22 to 42 days of age. In the first experiment, we used 1500 Cobb male broilers at one day of age, distributed in a completely randomized design with ten treatments, five repetitions and 30 birds per experimental unit. In the second experiment, we used 1000 Cobb male broiler at 22 days of age, distributed in a completely randomized design with ten treatments, five repetitions and 20 birds per experimental unit. The treatments consisted of five levels of choline chloride 60% (400, 500, 600, 700 and 800 mg kg^-1) and five levels of vegetal source of choline (100, 150, 200, 250 and 300 mg kg^-1). There was no difference between the performance parameters of broilers in the periods of one to 21 and 22 to 42 days of age. The use of up to 100 mg kg^-1 of a vegetal source of choline can replace the use of choline chloride, in the studied levels, in corn-soybean meal diets for broilers from one to 21 and 22 to 42 days of age.