Modeling energy utilization and growth parameter description for broiler chickens.
Poult Sci
; 84(9): 1363-9, 2005 Sep.
Article
em En
| MEDLINE
| ID: mdl-16206556
Two experiments were conducted to develop and evaluate a model to estimate ME requirements and determine Gompertz growth parameters for broilers. The first experiment was conducted to determine maintenance energy requirements and the efficiencies of energy utilization for fat and protein deposition. Maintenance ME (MEm) requirements were estimated to be 157.8, 112.1, and 127.2 kcal of ME/kg(0.75) per day for broilers at 13, 23, and 32 degrees C, respectively. Environmental temperature (T) had a quadratic effect on maintenance requirements (MEm = 307.87 - 15.63T + 0.3105T(2); r2= 0.93). Energy requirements for fat and protein deposition were estimated to be 13.52 and 12.59 kcal of ME/g, respectively. Based on these coefficients, a model was developed to calculate daily ME requirements: ME = BW(0.75) (307.87 - 15.63T + 0.3105 T2) + 13.52 Gf + 12.59 Gp. This model considers live BW, the effects of environmental temperature, and fractional fat (Gf) and protein (Gp) deposition. The second experiment was carried out to estimate the growth parameters of Ross broilers and to collect data to evaluate the ME requirement model proposed. Live BW, empty feather-free carcass, weight of the feathers, and carcass chemical compositions were analyzed until 16 wk of age. Parameters of Gompertz curves for each component were estimated. Males had higher growth potential and higher capacity to deposit nutrients than females, except for fat deposition. Data of BW and body composition collected in this experiment were fitted into the energy model proposed herein and the equations described by Emmans (1989) and Chwalibog (1991). The daily ME requirements estimated by the model determined in this study were closer to the ME intake observed in this trial compared with other models.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Galinhas
/
Metabolismo Energético
/
Modelos Biológicos
Limite:
Animals
Idioma:
En
Revista:
Poult Sci
Ano de publicação:
2005
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Reino Unido