Determinação da energia metabolizável e balanço de nitrogênio de dietas com diferentes teores de proteína bruta para frangos de corte

A metabolism trial was carried out in metabolic cages in a completely randomized experimental design to evaluate the effect of CP reduction on nutrients and energy digestibility in the diets of broiler chickens. A hundred sixty male broiler chickens were randomly allotted to four treatments (CP levels) and four replicates of 10 birds each. The crude protein levels used in the diets were 21, 19, 17 and 15. The total excreta was colleted and recorded from 25 to 29 days of age. The CP reduction improved dry matter and energy digestibility linearly. A quadratic effect of the CP level on CP digestibility was observed. The maximum digestibility was estimated for broilers fed 15.3% CP diets. The nitrogen intake and excretion decreased linearly with the CP reduction. The maximum retained nitrogen and nitrogen efficiency utilization were estimated for broilers fed 18.3 and 15.3% CP diets, respectively. No effect of CP levels on ME was observed.

[1]  M. Zaghari,et al.  Effects of fortifying low crude protein diet with crystalline amino acids on performance, blood ammonia level, and excreta characteristics of broiler chicks. , 2008, Poultry science.

[2]  Édison José Fassani,et al.  Redução de proteína e fósforo em rações com fitase para frangos de corte no período de 1 a 21 dias de idade: desempenho e teores de minerais na cama , 2006 .

[3]  M. Macari,et al.  Dietas de baixa proteína no desempenho de frangos criados em diferentes temperaturas , 2006 .

[4]  M. Macari,et al.  Protein Levels and Environmental Temperature Effects on Carcass Characteristics, Performance, and Nitrogen Excretion of Broiler Chickens from 7 to 21 Days of Age , 2005 .

[5]  B. Kerr,et al.  Response of broiler chicks to essential and non-essential amino acid supplementation of low crude protein diets , 2005 .

[6]  Maria Auxiliadora Andrade,et al.  Desempenho de frangos de corte alimentados com rações pré-iniciais contendo diferentes níveis de proteína bruta e energia metabolizável , 2003 .

[7]  J. van Milgen,et al.  Energetic efficiency of starch, protein and lipid utilization in growing pigs. , 2001, The Journal of nutrition.

[8]  E. Pfeffer,et al.  Low-protein amino acid-supplemented diets in broiler-chickens: effects on performance, carcass characteristics, whole-body composition and efficiencies of nutrient utilisation , 2000 .

[9]  B. Kerr,et al.  Amino Acid Supplementation of Low-Protein Broiler Diets: 2. Formulation on an Ideal Amino Acid Basis , 1999 .

[10]  R. Blair,et al.  A Quantitative Assessment of Reduced Protein Diets and Supplements to Improve Nitrogen Utilization , 1999 .

[11]  M. Kirchgessner,et al.  INFLUENCE OF DIETARY LEVEL OF DISPENSABLE AMINO ACIDS ON NITROGEN BALANCE AND WHOLE-BODY PROTEIN TURNOVER IN GROWING PIGS , 1999 .

[12]  R. Gates,et al.  The effect of dietary protein and phosphorus on ammonia concentration and litter composition in broilers. , 1998, Poultry science.

[13]  J. Noblet,et al.  Effect of protein and lysine levels in the diet on body gain composition and energy utilization in growing pigs. , 1987, Journal of animal science.

[14]  J. D. McDonald,et al.  Effects of changes in the intakes of protein and non-protein energy on whole-body protein turnover in growing pigs , 1981, British Journal of Nutrition.