Prediction of body composition by total body electrical conductivity technique is affected by fat reserves of Japanese quail

• Published in: Poultry science 2010-11, Vol.89 (11), p.2506-2513
• Main Authors: Hyánková, L, Szebestová, Z
• Format: Article
• Language: English
• Subjects: Adipose Tissue - anatomy & histology; Adipose Tissue - physiology; Aging - physiology; animal growth; Animals; biological development; Body Composition; body fat; body fat distribution; Body Water; Body Weight; carcass composition; carcass quality; Coturnix - anatomy & histology; Coturnix - physiology; Electric Conductivity; electrical conductivity; equations; Female; Japanese quails; lean meat; linear models; lipid content; Lipids - analysis; Organ Size; poultry production; prediction; Regression Analysis; screening; sexual maturity; total body electrical conductivity technique; water content
• ISSN: 0032-5791; 1525-3171
• DOI: 10.3382/ps.2009-00370

The effect of fat accumulation on the prediction of in vivo body composition by a total body electrical conductivity (TOBEC) technique was evaluated using Japanese quail at 2 life periods (0 to 21 d and 28 to 70 d of age) that differ significantly in the fatness of birds. In total, 119 quail of 14 age categories were weighed and scanned by the TOBEC analyzer, and their carcasses were subjected to chemical analysis. The prediction equations for chemical composition (percentage of water, lipids, and lean tissue) and body masses (weight of body, water, lipids, and lean tissue) were obtained by linear regression analysis. The equations involved the E-value as the independent variable. In both growth phases, a high accuracy of estimation was found for the total body, lean, and water masses (0.85 [less-than or equal to] R² [less-than or equal to] 0.98), whereas a low accuracy of estimation was observed for percentages of lipids, lean tissue, and water (0.27 [less-than or equal to] R² [less-than or equal to] 0.64). Most of the variables showed a worse estimation in the late than in the early growth phase; the maximum difference was observed for the lipid mass (R² = 0.35 vs. 0.90, respectively). The correlations between analyzed variables and the residual error distributions of regression models demonstrated that the lower power of the models in the late versus early growth phase may be attributed to an enhanced fat accumulation in sexually mature birds. Their high fat reserves considerably decrease body hydration, which negatively influences the estimation of body composition based upon the TOBEC procedure.