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

Abstract

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 <0.05) in weight gain and feed conversion. Increasing levels of ME and DL caused significant interaction (P <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 <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. Key words: Performance, broiler, intestinal morphology ResumoO experimento foi conduzido com o objetivo de avaliar o efeito dos níveis de energia metabolizável (EM) e de lisina digestível (LD) no desempenho de pintos de corte de 8 a 21 dias de idade. Foram utilizados 864 pintos de corte, com peso médio de 160 ± 5g, distribuídos em um delineamento inteiramente casualizado ao acaso, em 48 boxes (unidade experimental), e esquema fatorial 4x4 sendo quatro níveis de EM (2.700; 2.825; 2.950; e 3.075 kcal kg -1 ) e quatro níveis de LD (1,080; 1,187; 1,295 e 1,403%) resultando em 16 tratamentos com três repetições. Os aumentos dos níveis de EM e de LD nas rações promoveram interação (P<0,05) no ganho de peso, conversão alimentar, taxa de deposição de proteína

Interactions between lipid source and vitamin A on broiler performance, blood parameters, fat and protein deposition rate, and bone development

“…Even though they were influenced by vitamin A supplementation at 21 d of age, the FDR values obtained in this study were similar to those found by Nunes et al. (2015) for broilers of the same age fed diets with different levels of ME and digestible lysine levels, which averaged 3.511 g d −1 .…”

“…However, they were lower than those obtained by Dias (2015) of 6.45 g d −1 for broilers at 21 d of age fed diets containing different levels of lysine. For the mean values of PDR found in this study (7.529 g d −1 ), the results are between those obtained by Nunes et al. (2015) of 4.707 g d −1 and Dias (2015) of 13.8 g d −1 .…”